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3. Prospects for Galactic and stellar astrophysics with asteroseismology of giant stars in the TESS continuous viewing zones and beyond

Author

J Ted Mackereth, Andrea Miglio, Yvonne Elsworth, Benoit Mosser, Savita Mathur, Rafael A Garcia, Domenico Nardiello, Oliver J Hall, Mathieu Vrard, Warrick H Ball, Sarbani Basu, Rachael L Beaton, Paul G Beck, Maria Bergemann, Diego Bossini, Luca Casagrande, Tiago L Campante, William J Chaplin, Cristina Chiappini, Léo Girardi, Andreas Christ Sølvsten Jørgensen, Saniya Khan, Josefina Montalbán, Martin B Nielsen, Marc H Pinsonneault, Thaíse S Rodrigues, Aldo Serenelli, Victor Silva Aguirre, Dennis Stello, Jamie Tayar, Johanna Teske, Jennifer L van Saders, and Emma Willett

Published
2021
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4. A variational encoder–decoder approach to precise spectroscopic age estimation for large Galactic surveys

Author

Henry W Leung, Jo Bovy, J Ted Mackereth, and Andrea Miglio

Subjects
Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Astrophysics of Galaxies
Abstract

Constraints on the formation and evolution of the Milky Way Galaxy require multidimensional measurements of kinematics, abundances, and ages for a large population of stars. Ages for luminous giants, which can be seen to large distances, are an essential component of studies of the Milky Way, but they are traditionally very difficult to estimate precisely for a large data set and often require careful analysis on a star-by-star basis in asteroseismology. Because spectra are easier to obtain for large samples, being able to determine precise ages from spectra allows for large age samples to be constructed, but spectroscopic ages are often imprecise and contaminated by abundance correlations. Here we present an application of a variational encoder–decoder on cross-domain astronomical data to solve these issues. The model is trained on pairs of observations from APOGEE and Kepler of the same star in order to reduce the dimensionality of the APOGEE spectra in a latent space while removing abundance information. The low dimensional latent representation of these spectra can then be trained to predict age with just ∼1000 precise seismic ages. We demonstrate that this model produces more precise spectroscopic ages ($\sim 22~{{\ \rm per\ cent}}$ overall, $\sim 11~{{\ \rm per\ cent}}$ for red-clump stars) than previous data-driven spectroscopic ages while being less contaminated by abundance information (in particular, our ages do not depend on [α/M]). We create a public age catalogue for the APOGEE DR17 data set and use it to map the age distribution and the age-[Fe/H]-[α/M] distribution across the radial range of the Galactic disc.

Published
2023

9. TOI-257b (HD 19916b): a warm sub-saturn orbiting an evolved F-type star

Author

Brett C. Addison, Duncan J. Wright, Belinda A. Nicholson, Bryson Cale, Teo Mocnik, Daniel Huber, Peter Plavchan, Robert A. Wittenmyer, Andrew Vanderburg, William J. Chaplin, Ashley Chontos, Jake T. Clark, Jason D. Eastman, Carl Ziegler, Rafael Brahm, Bradley D. Carter, Mathieu Clerte, Nestor Espinoza, Jonathan Horner, John Bentley, Andres Jordan, Stephen R. Kane, John F. Kielkopf, Emilie Laychock, Matthew W. Mengel, Jack Okumura, Keivan G. Stassun, Timothy R. Bedding, Brendan P. Bowler, Andrius Burnelis, Sergi Blanco-Cuaresma, Michaela Collins, Ian Crossfield, Allen B. Davis, Dag Evensberget, Alexis Heitzmann, Steve B. Howell, Nicholas Law, Andrew W. Mann, Stephen C. Marsden, Rachel A. Matson, James H. O’Connor, Avi Shporer, Catherine Stevens, C. G. Tinney, Christopher Tylor, Songhu Wang, Hui Zhang, Thomas Henning, Diana Kossakowski, George Ricker, Paula Sarkis, Martin Schlecker, Pascal Torres, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Ismael Mireles, Pam Rowden, Joshua Pepper, Tansu Daylan, Joshua E. Schlieder, Karen A. Collins, Kevin I. Collins, Thiam-Guan Tan, Warrick H. Ball, Sarbani Basu, Derek L. Buzasi, Tiago L. Campante, Enrico Corsaro, L. Gonz´alez-Cuesta, Guy R. Davies, Leandro de Almeida, Jose-Dias do Nascimento Jr, Rafael A. Garcpıa, Zhao Guo, Rasmus Handberg, Saskia Hekker, Daniel R. Hey, Thomas Kallinger, Steven D. Kawaler, Cenk Kayhan, James S. Kuszlewicz, Mikkel N. Lund, Alexander Lyttle, Savita Mathur, Andrea Miglio, Benoit Mosser, Martin B. Nielsen, Aldo M. Serenelli, Victor Silva Aguirre, and Nathalie Themeßl

Subjects
Astrophysics
Abstract

We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the MINERVA-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of M(P) = 0.138 ± 0.023 M(J) (43.9 ± 7.3 Mꚛ), a radius of R(P) = 0.639 ± 0.013 R(J) (7.16 ± 0.15 Rꚛ⁠), bulk density of 0.65 (+0.12,−0.11) (cgs), and period 18.38818 (+0.00085,−0.00084) days⁠. TOI-257b orbits a bright (V = 7.612 mag) somewhat evolved late F-type star with M⁎ = 1.390 ± 0.046 M(sun)⁠, R⁎ = 1.888 ± 0.033 R(sun)⁠, T(eff) = 6075 ± 90 K⁠, and 𝜈sin 𝑖 = 11.3 ± 0.5 km/s. Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a ∼71 day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars (∼100) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.

Published
2020
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10. The K2 Galactic Archaeology Program Data Release 3: Age-abundance Patterns in C1–C8 and C10–C18

Author

Joel C. Zinn, Dennis Stello, Yvonne Elsworth, Rafael A. García, Thomas Kallinger, Savita Mathur, Benoît Mosser, Marc Hon, Lisa Bugnet, Caitlin Jones, Claudia Reyes, Sanjib Sharma, Ralph Schönrich, Jack T. Warfield, Rodrigo Luger, Andrew Vanderburg, Chiaki Kobayashi, Marc H. Pinsonneault, Jennifer A. Johnson, Daniel Huber, Sven Buder, Meridith Joyce, Joss Bland-Hawthorn, Luca Casagrande, Geraint F. Lewis, Andrea Miglio, Thomas Nordlander, Guy R. Davies, Gayandhi De Silva, William J. Chaplin, and Victor Silva Aguirre

Published
2022
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11. Detection and Characterization of Oscillating Red Giants: First Results from the TESS Satellite

Author

Victor Silva Aguirre, Dennis Stello, Amalie Stokholm, Jakob R. Mosumgaard, Warrick H. Ball, Sarbani Basu, Diego Bossini, Lisa Bugnet, Derek Buzasi, Tiago L. Campante, Lindsey Carboneau, William J. Chaplin, Enrico Corsaro, Guy R. Davies, Yvonne Elsworth, Rafael A. Garcia, Patrick Gaulme, Oliver J. Hall, Rasmus Handberg, Marc Hon, Thomas Kallinger, Liu Kang, Mikkel N. Lund, Savita Mathur, Alexey Mints, Benoit Mosser, Zeynep Celik Orhan, Thaise S. Rodrigues, Mathieu Vrard, Mutlu Yıldız, Joel C. Zinn, Sibel Ortel, Paul G. Beck, Keaton J. Bell, Zhao Guo, Chen Jiang, James S. Kuszlewicz, Charles A. Kuehn, Tanda Li, Mia S. Lundkvist, Marc Pinsonneault, Jamie Tayar, Margarida S. Cunha, Saskia Hekker, Daniel Huber, Andrea Miglio, Mario J. P. F. G. Monteiro, Ditte Slumstrup, Mark L. Winther, George Angelou, Othman Benomar, Attila Bodi, Bruno L. De Moura, Sebastien Deheuvels, Aliz Derekas, Maria Pia Di Mauro, Marc-Antoine Dupret, Antonio Jimenez, Yveline Lebreton, Jaymie Matthews, Nicolas Nardetto, Jose D. do Nascimento Jr, Filipe Pereira, Luisa F. Rodriguez Díaz, Aldo M. Serenelli, Emanuele Spitoni, Edita Stonkute, Juan Carlos Suarez, Robert Szabo, Vincent Van Eylen, Rita Ventura, Kuldeep Verma, Achim Weiss, Tao Wu, Thomas Barclay, Jorgen Christensen-Dalsgaard, Jon M Jenkins, Hans Kjeldsen, George R Ricker, Sara Seager, and Roland Vanderspek

Subjects
Astrophysics, Astronomy
Abstract

Since the onset of the “space revolution” of high-precision high-cadence photometry, asteroseismology has been demonstrated as a powerful tool for informing Galactic archeology investigations. The launch of the NASA Transiting Exoplanet Survey Satellite (TESS) mission has enabled seismic-based inferences to go full sky— providing a clear advantage for large ensemble studies of the different Milky Way components. Here we demonstrate its potential for investigating the Galaxy by carrying out the first asteroseismic ensemble study of red giant stars observed by TESS. We use a sample of 25 stars for which we measure their global asteroseimic observables and estimate their fundamental stellar properties, such as radius, mass, and age. Significant improvements are seen in the uncertainties of our estimates when combining seismic observables from TESS with astrometric measurements from the Gaia mission compared to when the seismology and astrometry are applied separately. Specifically, when combined we show that stellar radii can be determined to a precision of a few percent, masses to 5%–10%, and ages to the 20% level. This is comparable to the precision typically obtained using end-of-mission Kepler data.

Published
2020
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12. Chasing the impact of the Gaia-Sausage-Enceladus merger on the formation of the Milky Way thick disc

Author

Ioana Ciucă, Daisuke Kawata, Yuan-Sen Ting, Robert J J Grand, Andrea Miglio, Michael Hayden, Junichi Baba, Francesca Fragkoudi, Stephanie Monty, Sven Buder, and Ken Freeman

Subjects
Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

We employ our Bayesian Machine Learning framework BINGO (Bayesian INference for Galactic archaeOlogy) to obtain high-quality stellar age estimates for 68,360 red giant and red clump stars present in the 17th data release of the Sloan Digital Sky Survey, the APOGEE-2 high-resolution spectroscopic survey. By examining the denoised age-metallicity relationship of the Galactic disc stars, we identify a drop in metallicity with an increase in [Mg/Fe] at an early epoch, followed by a chemical enrichment episode with increasing [Fe/H] and decreasing [Mg/Fe]. This result is congruent with the chemical evolution induced by an early-epoch gas-rich merger identified in the Milky Way-like zoom-in cosmological simulation Auriga. In the initial phase of the merger of Auriga 18 there is a drop in metallicity due to the merger diluting the metal content and an increase in the [Mg/Fe] of the primary galaxy. Our findings suggest that the last massive merger of our Galaxy, the Gaia-Sausage-Enceladus, was likely a significant gas-rich merger and induced a starburst, contributing to the chemical enrichment and building of the metal-rich part of the thick disc at an early epoch., 5 pages, 5 figures, Accepted 2023 March 6 in MNRAS

Published
2022

13. KIC 7955301: a hierarchical triple system with eclipse timing variations and an oscillating red giant

Author

Patrick Gaulme, Tamás Borkovits, Thierry Appourchaux, Krešimir Pavlovski, Federico Spada, Charlotte Gehan, Joel Ong, Andrea Miglio, Andrew Tkachenko, Benoît Mosser, Mathieu Vrard, Mansour Benbakoura, Stephen Drew Chojnowski, Jean Perkins, Anne Hedlund, Jason Jackiewicz, P. Gaulme, T. Borkovit, T. Appourchaux, K. Pavlovski, F. Spada, C. Gehan, J. Ong, A. Miglio, A. Tkachenko, B. Mosser, M. Vrard, M. Benbakoura, S. D. Chojnowski, J. Perkin, A. Hedlund, and J. Jackiewicz

Subjects
binaries: close, binaries: spectroscopic, stars: oscillations, stars: evolution, techniques: radial velocities, techniques: photometric, astro-ph.SR, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

KIC 7955301 is a hierarchical triple system with eclipse timing and depth variations discovered by the Kepler mission. It is composed of a non-eclipsing primary star at the bottom of the red giant branch on a 209-day orbit with a K/G-type main-sequence inner eclipsing binary, orbiting in 15.3 days. This system was noted for the large amplitude of its eclipse timing variations (4 hours), and the clear solar-like oscillations of the red-giant component, including p-modes of degree up to l=3 and mixed l=1 modes. The system is a single-lined spectroscopic triple. We perform a dynamical model by combining the Kepler photometric data, eclipse timing variations, and radial-velocity data obtained at Apache Point (ARCES) and Haute Provence (SOPHIE) observatories. The dynamical mass of the red-giant is determined with a 2% precision at 1.30 (+0.03,-0.02) solar mass. We perform asteroseismic modeling based on the global seismic parameters and on the individual frequencies. Both methods lead to a mass of the red giant that matches the dynamical mass within the uncertainties. Asteroseismology also reveals the rotation rate of the core (15 days), the envelope (150 days), and the inclination (75 deg) of the red giant. Three different approaches lead to an age between 3.3 and 5.8 Gyr, which highlights the difficulty of determining stellar ages despite the exceptional wealth of available information. On short timescales, the inner binary exhibits eclipses with varying depths during a 7.3-year long interval, and no eclipses during the consecutive 11.9 years. This is why Kepler could detect its eclipses, TESS will not, and the future ESA PLATO mission should. Over the long term, the system owes its evolution to the evolution of its individual components. It could end its current smooth evolution by merging by the end of the red giant or the asymptotic giant branch of the primary star., Accepted in A&A, 25 pages, 17 figures, 7 tables

Published
2022

14. Asteroseismology of overmassive, undermassive, and potential past members of the open cluster NGC 6791

Author

Andrea Miglio, Torben Arentoft, Jens Jessen-Hansen, Karsten Brogaard, Brogaard, K, Arentoft, T, Jessen-Hansen, J, and Miglio, A

Subjects
oscillations [stars], peculiar [stars], Physics, 010308 nuclear & particles physics, fundamental parameters [stars], FOS: Physical sciences, stars: peculiar– stars: fundamental parameters – stars: evolution – stars: oscillations – open clusters and associations: individual: NGC 6791, Astronomy and Astrophysics, Astrophysics, Radius, Effective temperature, Giant star, 01 natural sciences, Asteroseismology, Photometry (astronomy), Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, evolution [stars], 0103 physical sciences, Cluster (physics), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), individual: NGC 6791 [open clusters and associations], Open cluster
Abstract

We perform an asteroseismic investigation of giant stars in the field of NGC 6791 with previous indications of atypical evolution. The analysis makes use of observations from Kepler and Gaia in combination with ground-based photometry, a literature radial-velocity study, and measurements of eclipsing binaries in the cluster. We derive mass, radius, effective temperature, evolutionary stage and apparent distance modulus of each target. Among the investigated cluster giants we find clear evidence of overmassive and undermassive members, and non-members with strong hints of potential past membership. Our results indicate that about 10% of the red giants in the cluster have experienced mass-transfer or a merger. High resolution, high-S/N spectroscopic follow-up could confirm potential past membership of the non-members, and reveal whether certain element abundances might expose the non-standard evolution of overmassive and undermassive stars. If so, field stars of similar type could be identified as what they are, i.e. over- or undermassive stars, and not mistakenly classified as younger or older than they are., 14 pages, 5 figures, accepted for publication in MNRAS

Published
2021

15. Chronologically dating the early assembly of the Milky Way

Author

Jason W. Ferguson, J. Ted Mackereth, B. M. Rendle, Josefina Montalbán, Fiorenzo Vincenzo, Emma Willett, Guy R. Davies, M. Vrard, Cristina Chiappini, Saniya Khan, Richard Scuflaire, Andrea Miglio, Arlette Noels, B. Mosser, Martin Bo Nielsen, William J. Chaplin, Oliver J. Hall, Walter E. van Rossem, Gaël Buldgen, Montalban J., Mackereth J.T., Miglio A., Vincenzo F., Chiappini C., Buldgen G., Mosser B., Noels A., Scuflaire R., Vrard M., Willett E., Davies G.R., Hall O.J., Bo Nielsen M., Khan S., Rendle B.M., van Rossem W.E., Ferguson J.W., and Chaplin W.J.

Subjects
010504 meteorology & atmospheric sciences, Milky Way, CHEMICAL EVOLUTION, STELLAR POPULATIONS, RED GIANTS, GAIA, ASTEROSEISMOLOGY, KINEMATICS, AGES, HALO, OSCILLATIONS, ABUNDANCES, Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Compact star, 01 natural sciences, 0103 physical sciences, Thick disk, Satellite galaxy, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, education.field_of_study, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Accretion (astrophysics), Stars, Astrophysics - Solar and Stellar Astrophysics, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Geology
Abstract

The standard cosmological model ($\Lambda$-CDM) predicts that galaxies are built through hierarchical assembly on cosmological timescales$^{1,2}$. The Milky Way, like other disc galaxies, underwent violent mergers and accretion of small satellite galaxies in its early history. Thanks to Gaia-DR2$^3$ and spectroscopic surveys$^4$, the stellar remnants of such mergers have been identified$^{5-7}$. The chronological dating of such events is crucial to uncover the formation and evolution of the Galaxy at high redshift, but it has so far been challenging owing to difficulties in obtaining precise ages for these oldest stars. Here we combine asteroseismology -- the study of stellar oscillations -- with kinematics and chemical abundances, to estimate precise stellar ages ($\sim$ 11%) for a sample of stars observed by the $\mathit{Kepler}$ space mission$^8$. Crucially, this sample includes not only some of the oldest stars that were formed inside the Galaxy, but also stars formed externally and subsequently accreted onto the Milky Way. Leveraging this resolution in age, we provide compelling evidence in favour of models in which the Galaxy had already formed a substantial population of its stars (which now reside mainly in its thick disc) before the in-fall of the satellite galaxy Gaia-Enceladus/Sausage$^{5,6}$ around 10 billions years ago, Comment: Updated with the final version accepted for publication as a Letter in Nature Astronomy (29 pages, 10 figures, 2 tables, including main article and methods section). Improved presentation of results, which have not changed from the previous version

Published
2021

16. CORALIE radial velocity search for companions around evolved stars (CASCADES): II. Seismic masses for three red giants orbited by long-period massive planets

Author

G. Ottoni, M. Mayor, Yvonne Elsworth, C. Pezzotti, Andrea Miglio, D. Segransan, Alexander Lyttle, Stéphane Udry, C. Lovis, Warrick H. Ball, Guy R. Davies, P. Eggenberger, Gaël Buldgen, and G. Buldgen, G. Ottoni, C. Pezzotti, A. Lyttle, P. Eggenberger, S. Udry, D. Ségransan, A. Miglio, M. Mayor, C. Lovis, Y. Elsworth, G.R. Davies, W.H. Ball

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), Planetary system, Computer Science::Information Retrieval, Asteroseismology, FOS: Physical sciences, Astronomy and Astrophysics, Stars: fundamental parameter, Astrophysics, Radial velocity, Stars, Stars: individual: HD 22532, Stars: individual: HD 69123, Astrophysics - Solar and Stellar Astrophysics, Stars: individual: HD 64121, Space and Planetary Science, Planet, Long period, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The advent of asteroseismology as the golden path to precisely characterize single stars naturally led to synergies with the field of exoplanetology. Today, the precise determination of stellar masses, radii and ages for exoplanet-host stars is a driving force in the development of dedicated software and techniques to achieve this goal. However, as various approaches exist, it is clear that they all have advantages and inconveniences and that there is a trade-off between accuracy, efficiency, and robustness of the techniques. We aim to compare and discuss various modelling techniques for exoplanet-host red giant stars for which TESS data are available. The results of the seismic modelling are then used to study the dynamical evolution and atmospheric evaporation of the planetary systems. We study, in detail, the robustness, accuracy and precision of various seismic modelling techniques when applied to four exoplanet-host red giants observed by TESS. We discuss the use of global seismic indexes, the use of individual radial frequencies and that of non-radial oscillations. In each case, we discuss the advantages and inconveniences of the modelling technique. We determine precise and accurate masses of exoplanet-host red giant stars orbited by long-period Jupiter-like planets using various modelling techniques. For each target, we also provide a model-independent estimate of the mass from a mean density inversion combined with radii values from Gaia and spectroscopic data. We show that no engulfment or migration is observed for these targets, even if their evolution is extended beyond their estimated seismic ages up the red giant branch., Accepted for publication in Astronomy and Astrophysics. Part of the CASCADES series of papers

Published
2022

17. The distribution of [$\alpha$/Fe] in the Milky Way disc

Author

David H. Weinberg, Rebecca Lane, Fiorenzo Vincenzo, Alexandre Roman-Lopes, Andrea Miglio, and Fiorenzo Vincenzo, David H. Weinberg, Andrea Miglio, Richard R. Lane, Alexandre Roman-Lopes

Subjects
Physics, Galaxy: stellar content, stars: abundances, Distribution (number theory), 010308 nuclear & particles physics, Milky Way, Galaxy: disc, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy: abundance, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Using a sample of red giant stars from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) Data Release 16, we infer the conditional distribution $p([\alpha/\text{Fe}]\,|\,[\text{Fe/H}])$ in the Milky Way disk for the $\alpha$-elements Mg, O, Si, S, and Ca. In each bin of [Fe/H] and Galactocentric radius $R$, we model $p([\alpha/\text{Fe}])$ as a sum of two Gaussians, representing "low-$\alpha$" and "high-$\alpha$" populations with scale heights $z_1=0.45\,\text{kpc}$ and $z_2=0.95\,\text{kpc}$, respectively. By accounting for age-dependent and $z$-dependent selection effects in APOGEE, we infer the [$\alpha$/Fe] distributions that would be found for a fair sample of long-lived stars covering all $z$. Near the Solar circle, this distribution is bimodal at sub-solar [Fe/H], with the low-$\alpha$ and high-$\alpha$ peaks clearly separated by a minimum at intermediate [$\alpha$/Fe]. In agreement with previous results, we find that the high-$\alpha$ population is more prominent at smaller $R$, lower [Fe/H], and larger $|z|$, and that the sequence separation is smaller for Si and Ca than for Mg, O, and S. We find significant intrinsic scatter in [$\alpha$/Fe] at fixed [Fe/H] for both the low-$\alpha$ and high-$\alpha$ populations, typically $\sim 0.04$-dex. The means, dispersions, and relative amplitudes of this two-Gaussian description, and the dependence of these parameters on $R$, [Fe/H], and $\alpha$-element, provide a quantitative target for chemical evolution models and a test for hydrodynamic simulations of disk galaxy formation. We argue that explaining the observed bimodality will probably require one or more sharp transitions in the disk's gas accretion, star formation, or outflow history in addition to radial mixing of stellar populations., Comment: Accepted for publication in MNRAS

Published
2021

18. The K2 Galactic Archaeology Program Data Release 2:Asteroseismic Results from Campaigns 4, 6, and 7

Author

Thomas Kallinger, Jack T. Warfield, Daniel Huber, Caitlin D. Jones, Sanjib Sharma, Marc Hon, Jennifer A. Johnson, L. Bugnet, Guy R. Davies, Joel C. Zinn, Dennis Stello, William J. Chaplin, Ralph Schönrich, Marc H. Pinsonneault, Benoit Mosser, Andrea Miglio, Yvonne Elsworth, Rafael A. García, Rodrigo Luger, Victor Silva Aguirre, Savita Mathur, Joel C. Zinn, Dennis Stello, Yvonne Elsworth, Rafael A. García, Thomas Kallinger, Savita Mathur, Benoît Mosser, Lisa Bugnet, Caitlin Jones, Marc Hon, Sanjib Sharma, Ralph Schönrich, Jack T. Warfield, Rodrigo Luger, Marc H. Pinsonneault, Jennifer A. Johnson, Daniel Huber, Victor Silva Aguirre, William J. Chaplin, Guy R. Davies, Andrea Miglio, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)

Subjects
Red giant, 01 natural sciences, Red giant branch, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Red giant clump, [PHYS]Physics [physics], Physics, 05 social sciences, Asteroseismology, 050301 education, Radius, Red-giant branch, Astrophysics - Solar and Stellar Astrophysics, Physical Sciences, Catalog, Astrophysics::Earth and Planetary Astrophysics, Data release, PIPELINE, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, AGE, Stellar radii, 0103 physical sciences, OSCILLATIONS, PHOTOMETRY, Stellar masses, Red clump, DISTANCES, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Science & Technology, Astronomy and Astrophysics, Effective temperature, RED, Archaeology, Astrophysics - Astrophysics of Galaxies, Stars, Stellar masse, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), High Energy Physics::Experiment, Catalogs, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 0503 education, STARS
Abstract

Studies of Galactic structure and evolution have benefitted enormously from Gaia kinematic information, though additional, intrinsic stellar parameters like age are required to best constrain Galactic models. Asteroseismology is the most precise method of providing such information for field star populations $\textit{en masse}$, but existing samples for the most part have been limited to a few narrow fields of view by the CoRoT and Kepler missions. In an effort to provide well-characterized stellar parameters across a wide range in Galactic position, we present the second data release of red giant asteroseismic parameters for the K2 Galactic Archaeology Program (GAP). We provide $\nu_{\mathrm{max}}$ and $\Delta \nu$ based on six independent pipeline analyses; first-ascent red giant branch (RGB) and red clump (RC) evolutionary state classifications from machine learning; and ready-to-use radius & mass coefficients, $\kappa_R$ & $\kappa_M$, which, when appropriately multiplied by a solar-scaled effective temperature factor, yield physical stellar radii and masses. In total, we report 4395 radius and mass coefficients, with typical uncertainties of $3.3\% \mathrm{\ (stat.)} \pm 1\% \mathrm{\ (syst.)}$ for $\kappa_R$ and $7.7\% \mathrm{\ (stat.)} \pm 2\% \mathrm{\ (syst.)}$ for $\kappa_M$ among RGB stars, and $5.0\% \mathrm{\ (stat.)} \pm 1\% \mathrm{\ (syst.)}$ for $\kappa_R$ and $10.5\% \mathrm{\ (stat.)} \pm 2\% \mathrm{\ (syst.)}$ for $\kappa_M$ among RC stars. We verify that the sample is nearly complete -- except for a dearth of stars with $\nu_{\mathrm{max}} \lesssim 10-20\mu$Hz -- by comparing to Galactic models and visual inspection. Our asteroseismic radii agree with radii derived from Gaia Data Release 2 parallaxes to within $2.2 \pm 0.3\%$ for RGB stars and $2.0 \pm 0.6\%$ for RC stars., Comment: Published in ApJS

Published
2020

19. The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar, and APOGEE-2 Data

Author

null Abdurro’uf, Katherine Accetta, Conny Aerts, Víctor Silva Aguirre, Romina Ahumada, Nikhil Ajgaonkar, N. Filiz Ak, Shadab Alam, Carlos Allende Prieto, Andrés Almeida, Friedrich Anders, Scott F. Anderson, Brett H. Andrews, Borja Anguiano, Erik Aquino-Ortíz, Alfonso Aragón-Salamanca, Maria Argudo-Fernández, Metin Ata, Marie Aubert, Vladimir Avila-Reese, Carles Badenes, Rodolfo H. Barbá, Kat Barger, Jorge K. Barrera-Ballesteros, Rachael L. Beaton, Timothy C. Beers, Francesco Belfiore, Chad F. Bender, Mariangela Bernardi, Matthew A. Bershady, Florian Beutler, Christian Moni Bidin, Jonathan C. Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Nicholas Fraser Boardman, Adam S. Bolton, Médéric Boquien, Jura Borissova, Jo Bovy, W. N. Brandt, Jordan Brown, Joel R. Brownstein, Marcella Brusa, Johannes Buchner, Kevin Bundy, Joseph N. Burchett, Martin Bureau, Adam Burgasser, Tuesday K. Cabang, Stephanie Campbell, Michele Cappellari, Joleen K. Carlberg, Fábio Carneiro Wanderley, Ricardo Carrera, Jennifer Cash, Yan-Ping Chen, Wei-Huai Chen, Brian Cherinka, Cristina Chiappini, Peter Doohyun Choi, S. Drew Chojnowski, Haeun Chung, Nicolas Clerc, Roger E. Cohen, Julia M. Comerford, Johan Comparat, Luiz da Costa, Kevin Covey, Jeffrey D. Crane, Irene Cruz-Gonzalez, Connor Culhane, Katia Cunha, Y. Sophia Dai, Guillermo Damke, Jeremy Darling, James W. Davidson Jr., Roger Davies, Kyle Dawson, Nathan De Lee, Aleksandar M. Diamond-Stanic, Mariana Cano-Díaz, Helena Domínguez Sánchez, John Donor, Chris Duckworth, Tom Dwelly, Daniel J. Eisenstein, Yvonne P. Elsworth, Eric Emsellem, Mike Eracleous, Stephanie Escoffier, Xiaohui Fan, Emily Farr, Shuai Feng, José G. Fernández-Trincado, Diane Feuillet, Andreas Filipp, Sean P Fillingham, Peter M. Frinchaboy, Sebastien Fromenteau, Lluís Galbany, Rafael A. García, D. A. García-Hernández, Junqiang Ge, Doug Geisler, Joseph Gelfand, Tobias Géron, Benjamin J. Gibson, Julian Goddy, Diego Godoy-Rivera, Kathleen Grabowski, Paul J. Green, Michael Greener, Catherine J. Grier, Emily Griffith, Hong Guo, Julien Guy, Massinissa Hadjara, Paul Harding, Sten Hasselquist, Christian R. Hayes, Fred Hearty, Jesús Hernández, Lewis Hill, David W. Hogg, Jon A. Holtzman, Danny Horta, Bau-Ching Hsieh, Chin-Hao Hsu, Yun-Hsin Hsu, Daniel Huber, Marc Huertas-Company, Brian Hutchinson, Ho Seong Hwang, Héctor J. Ibarra-Medel, Jacob Ider Chitham, Gabriele S. Ilha, Julie Imig, Will Jaekle, Tharindu Jayasinghe, Xihan Ji, Jennifer A. Johnson, Amy Jones, Henrik Jönsson, Ivan Katkov, Dr. Arman Khalatyan, Karen Kinemuchi, Shobhit Kisku, Johan H. Knapen, Jean-Paul Kneib, Juna A. Kollmeier, Miranda Kong, Marina Kounkel, Kathryn Kreckel, Dhanesh Krishnarao, Ivan Lacerna, Richard R. Lane, Rachel Langgin, Ramon Lavender, David R. Law, Daniel Lazarz, Henry W. Leung, Ho-Hin Leung, Hannah M. Lewis, Cheng Li, Ran Li, Jianhui Lian, Fu-Heng Liang, Lihwai Lin, Yen-Ting Lin, Sicheng Lin, Chris Lintott, Dan Long, Penélope Longa-Peña, Carlos López-Cobá, Shengdong Lu, Britt F. Lundgren, Yuanze Luo, J. Ted Mackereth, Axel de la Macorra, Suvrath Mahadevan, Steven R. Majewski, Arturo Manchado, Travis Mandeville, Claudia Maraston, Berta Margalef-Bentabol, Thomas Masseron, Karen L. Masters, Savita Mathur, Richard M. McDermid, Myles Mckay, Andrea Merloni, Michael Merrifield, Szabolcs Meszaros, Andrea Miglio, Francesco Di Mille, Dante Minniti, Rebecca Minsley, Antonela Monachesi, Jeongin Moon, Benoit Mosser, John Mulchaey, Demitri Muna, Ricardo R. Muñoz, Adam D. Myers, Natalie Myers, Seshadri Nadathur, Preethi Nair, Kirpal Nandra, Justus Neumann, Jeffrey A. Newman, David L. Nidever, Farnik Nikakhtar, Christian Nitschelm, Julia E. O’Connell, Luis Garma-Oehmichen, Gabriel Luan Souza de Oliveira, Richard Olney, Daniel Oravetz, Mario Ortigoza-Urdaneta, Yeisson Osorio, Justin Otter, Zachary J. Pace, Nelson Padilla, Kaike Pan, Hsi-An Pan, Taniya Parikh, James Parker, Sebastien Peirani, Karla Peña Ramírez, Samantha Penny, Will J. Percival, Ismael Perez-Fournon, Marc Pinsonneault, Frédérick Poidevin, Vijith Jacob Poovelil, Adrian M. Price-Whelan, Anna Bárbara de Andrade Queiroz, M. Jordan Raddick, Amy Ray, Sandro Barboza Rembold, Nicole Riddle, Rogemar A. Riffel, Rogério Riffel, Hans-Walter Rix, Annie C. Robin, Aldo Rodríguez-Puebla, Alexandre Roman-Lopes, Carlos Román-Zúñiga, Benjamin Rose, Ashley J. Ross, Graziano Rossi, Kate H. R. Rubin, Mara Salvato, Sebástian F. Sánchez, José R. Sánchez-Gallego, Robyn Sanderson, Felipe Antonio Santana Rojas, Edgar Sarceno, Regina Sarmiento, Conor Sayres, Elizaveta Sazonova, Adam L. Schaefer, Ricardo Schiavon, David J Schlegel, Donald P. Schneider, Mathias Schultheis, Axel Schwope, Aldo Serenelli, Javier Serna, Zhengyi Shao, Griffin Shapiro, Anubhav Sharma, Yue Shen, Matthew Shetrone, Yiping Shu, Joshua D. Simon, M. F. Skrutskie, Rebecca Smethurst, Verne Smith, Jennifer Sobeck, Taylor Spoo, Dani Sprague, David V. Stark, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Alexander Stone-Martinez, Thaisa Storchi-Bergmann, Guy S. Stringfellow, Amelia Stutz, Yung-Chau Su, Manuchehr Taghizadeh-Popp, Michael S. Talbot, Jamie Tayar, Eduardo Telles, Johanna Teske, Ani Thakar, Christopher Theissen, Andrew Tkachenko, Daniel Thomas, Rita Tojeiro, Hector Hernandez Toledo, Nicholas W. Troup, Jonathan R. Trump, James Trussler, Jacqueline Turner, Sarah Tuttle, Eduardo Unda-Sanzana, José Antonio Vázquez-Mata, Marica Valentini, Octavio Valenzuela, Jaime Vargas-González, Mariana Vargas-Magaña, Pablo Vera Alfaro, Sandro Villanova, Fiorenzo Vincenzo, David Wake, Jack T. Warfield, Jessica Diane Washington, Benjamin Alan Weaver, Anne-Marie Weijmans, David H. Weinberg, Achim Weiss, Kyle B. Westfall, Vivienne Wild, Matthew C. Wilde, John C. Wilson, Robert F. Wilson, Mikayla Wilson, Julien Wolf, W. M. Wood-Vasey, Renbin Yan, Olga Zamora, Gail Zasowski, Kai Zhang, Cheng Zhao, Zheng Zheng, Kai Zhu, Institute of Astronomy [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Radboud University [Nijmegen], Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Instituto de Astrofisica de Canarias (IAC), Universidad de Antofagasta, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of St Andrews. School of Physics and Astronomy, University of St Andrews. Centre for Contemporary Art, European Space Agency, National Aeronautics and Space Administration (US), Alfred P. Sloan Foundation, and Abdurro'uf, Katherine Accetta, Conny Aerts, Victor Silva Aguirre, Romina Ahumada, Nikhil Ajgaonkar, N. Filiz Ak, Shadab Alam, Carlos Allende Prieto, Andres Almeida, Friedrich Anders, Scott F. Anderson, Brett H. Andrews, Borja Anguiano, Erik Aquino-Ortiz, Alfonso Aragon-Salamanca, Maria Argudo-Fernandez, Metin Ata, Marie Aubert, Vladimir Avila-Reese, Carles Badenes, Rodolfo H. Barba, Kat Barger, Jorge K. Barrera-Ballesteros, Rachael L. Beaton, Timothy C. Beers, Francesco Belfiore, Chad F. Bender, Mariangela Bernardi, Matthew A. Bershady, Florian Beutler, Christian Moni Bidin, Jonathan C. Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Nicholas Fraser Boardman, Adam S. Bolton, Mederic Boquien, Jura Borissova, Jo Bovy, W.N. Brandt, Jordan Brown, Joel R. Brownstein, Marcella Brusa, Johannes Buchner, Kevin Bundy, Joseph N. Burchett, Martin Bureau, Adam Burgasser, Tuesday K. Cabang, Stephanie Campbell, Michele Cappellari, Joleen K. Carlberg, Fabio Carneiro Wanderley, Ricardo Carrera, Jennifer Cash, Yan-Ping Chen, Wei-Huai Chen, Brian Cherinka, Cristina Chiappini, Peter Doohyun Choi, S. Drew Chojnowski, Haeun Chung, Nicolas Clerc, Roger E. Cohen, Julia M. Comerford, Johan Comparat, Luiz da Costa, Kevin Covey, Jeffrey D. Crane, Irene Cruz-Gonzalez, Connor Culhane, Katia Cunha, Y. Sophia Dai, Guillermo Damke, Jeremy Darling, James W. Davidson Jr., Roger Davies, Kyle Dawson, Nathan De Lee, Aleksandar M. Diamond-Stanic, Mariana Cano-Diaz, Helena Dominguez Sanchez, John Donor, Chris Duckworth, Tom Dwelly, Daniel J. Eisenstein, Yvonne P. Elsworth, Eric Emsellem, Mike Eracleous, Stephanie Escoffier, Xiaohui Fan, Emily Farr, Shuai Feng, Jose G. Fernandez-Trincado, Diane Feuillet, Andreas Filipp, Sean P Fillingham, Peter M. Frinchaboy , Sebastien Fromenteau, Lluis Galbany, Rafael A. Garcia, D. A. Garcia-Hernandez, Junqiang Ge, Doug Geisler, Joseph Gelfand, Tobias Geron, Benjamin J. Gibson, Julian Goddy, Diego Godoy-Rivera, Kathleen Grabowski, Paul J. Green, Michael Greener, Catherine J. Grier, Emily Griffith, Hong Guo, Julien Guy, Massinissa Hadjara, Paul Harding, Sten Hasselquist, Christian R. Hayes, Fred Hearty, Jesus Hernandez, Lewis Hill, David W. Hogg, Jon A. Holtzman, Danny Horta, Bau-Ching Hsieh, Chin-Hao Hsu, Yun-Hsin Hsu, Daniel Huber, Marc Huertas-Company, Brian Hutchinson, Ho Seong Hwang, Hector J. Ibarra-Medel, Jacob Ider Chitham, Gabriele S. Ilha, Julie Imig, Will Jaekle, Tharindu Jayasinghe, Xihan Ji, Jennifer A. Johnson, Amy Jones, Henrik Jonsson, Ivan Katkov, Dr. Arman Khalatyan, Karen Kinemuchi, Shobhit Kisku, Johan H. Knapen, Jean-Paul Kneib, Juna A. Kollmeier, Miranda Kong, Marina Kounkel, Kathryn Kreckel, Dhanesh Krishnarao, Ivan Lacerna, Richard R. Lane, Rachel Langgin, Ramon Lavender, David R. Law, Daniel Lazarz, Henry W. Leung, Ho-Hin Leung, Hannah M. Lewis, Cheng Li, Ran Li, Jianhui Lian, Fu-Heng Liang, Lihwai Lin, Yen-Ting Lin, Sicheng Lin, Chris Lintott, Dan Long, Penelope Longa-Pena, Carlos Lopez-Coba, Shengdong Lu, Britt F. Lundgren, Yuanze Luo, J. Ted Mackereth, Axel de la Macorra, Suvrath Mahadevan, Steven R. Majewski, Arturo Manchado, Travis Mandeville, Claudia Maraston, Berta Margalef-Bentabol, Thomas Masseron, Karen L. Masters, Savita Mathur, Richard M. McDermid, Myles Mckay, Andrea Merloni, Michael Merrifield, Szabolcs Meszaros, Andrea Miglio, Francesco Di Mille, Dante Minniti, Rebecca Minsley, Antonela Monachesi, Jeongin Moon, Benoit Mosser, John Mulchaey, Demitri Muna, Ricardo R. Munoz, Adam D. Myers, Natalie Myers, Seshadri Nadathur, Preethi Nair, Kirpal Nandra, Justus Neumann, Jeffrey A. Newman, David L. Nidever, Farnik Nikakhtar, Christian Nitschelm, Julia E. O'Connell, Luis Garma-Oehmichen, Gabriel Luan Souza de Oliveira, Richard Olney, Daniel Oravetz, Mario Ortigoza-Urdaneta, Yeisson Osorio, Justin Otter, Zachary J. Pace, Nelson Padilla, Kaike Pan, Hsi-An Pan, Taniya Parikh, James Parker, Sebastien Peirani, Karla Pena Ramirez, Samantha Penny, Will J. Percival, Ismael Perez-Fournon, Marc Pinsonneault, Frederick Poidevin, Vijith Jacob Poovelil, Adrian M. Price-Whelan, Anna Barbara de Andrade Queiroz, M. Jordan Raddick, Amy Ray, Sandro Barboza Rembold, Nicole Riddle, Rogemar A. Riffel, Rogerio Riffel, Hans-Walter Rix, Annie C. Robin, Aldo Rodriguez-Puebla, Alexandre Roman-Lopes, Carlos Roman-Zuniga, Benjamin Rose, Ashley J. Ross, Graziano Rossi, Kate H. R. Rubin, Mara Salvato, Sebastian F. Sanchez, Jose R. Sanchez-Gallego, Robyn Sanderson, Felipe Antonio Santana Rojas, Edgar Sarceno, Regina Sarmiento, Conor Sayres, Elizaveta Sazonova, Adam L. Schaefer, Ricardo Schiavon, David J Schlegel, Donald P. Schneider, Mathias Schultheis, Axel Schwope, Aldo Serenelli, Javier Serna, Zhengyi Shao, Griffin Shapiro, Anubhav Sharma, Yue Shen, Matthew Shetrone, Yiping Shu, Joshua D. Simon, M. F. Skrutskie, Rebecca Smethurst, Verne Smith, Jennifer Sobeck, Taylor Spoo, Dani Sprague, David V. Stark, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Alexander Stone-Martinez, Thaisa Storchi-Bergmann, Guy S. Stringfellow, Amelia Stutz, Yung-Chau Su, Manuchehr Taghizadeh-Popp, Michael S. Talbot, Jamie Tayar, Eduardo Telles, Johanna Teske, Ani Thakar, Christopher Theissen, Daniel Thomas, Andrew Tkachenko, Rita Tojeiro, Hector Hernandez Toledo, Nicholas W. Troup, Jonathan R. Trump, James Trussler, Jacqueline Turner, Sarah Tuttle, Eduardo Unda-Sanzana, Jose Antonio Vazquez-Mata, Marica Valentini, Octavio Valenzuela, Jaime Vargas-Gonzalez, Mariana Vargas-Magana, Pablo Vera Alfaro, Sandro Villanova, Fiorenzo Vincenzo, David Wake, Jack T. Warfield, Jessica Diane Washington, Benjamin Alan Weaver, Anne-Marie Weijmans, David H. Weinberg, Achim Weiss, Kyle B. Westfall, Vivienne Wild, Matthew C. Wilde, John C. Wilson, Robert F. Wilson, Mikayla Wilson, Julien Wolf, W. M. Wood-Vasey, Renbin Yan, Olga Zamora, Gail Zasowski, Kai Zhang, Cheng Zhao, Zheng Zheng, Zheng Zheng, Kai Zhu

Subjects
ABSORPTION-LINE SPECTRA, ACTIVE GALACTIC NUCLEI, anisotropic power spectrum, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics - astrophysics of galaxies, absorption-line spectra, FOS: Physical sciences, Astronomy & Astrophysics, large-scale structure, OSCILLATION SPECTROSCOPIC SURVEY, cluster chemical abundances, reverberation mapping project, Astronomi, astrofysik och kosmologi, LARGE-SCALE STRUCTURE, Astronomy, Astrophysics and Cosmology, QB Astronomy, OLD STELLAR POPULATIONS, CLUSTER CHEMICAL ABUNDANCES, Instrumentation and Methods for Astrophysics (astro-ph.IM), QC, QB, MCC, FINAL TARGETING STRATEGY, Science & Technology, REVERBERATION MAPPING PROJECT, DAS, Astronomy and Astrophysics, ANISOTROPIC POWER SPECTRUM, oscillation spectroscopic survey, Astrophysics - Astrophysics of Galaxies, final targeting strategy, sdss-iv manga, QC Physics, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), active galactic nuclei, Physical Sciences, old stellar populations, Astrophysics - Instrumentation and Methods for Astrophysics, SDSS-IV MANGA, Astrophysics - instrumentation and methods for Astrophysics
Abstract

Abdurro’uf et al., This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys., This publication uses data generated via the Zooniverse.org platform, development of which is funded by generous support, including a Global Impact Award from Google, and by a grant from the Alfred P. Sloan Foundation. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.

Published
2022

20. Cancelable templates for secure face verification based on deep learning and random projections

Author

Arslan Ali, Andrea Migliorati, Tiziano Bianchi, and Enrico Magli

Subjects
Biometrics, Face verification, Biometric authentication, Cancelable biometrics, Compressed sensing, Computer engineering. Computer hardware, TK7885-7895, Electronic computers. Computer science, QA75.5-76.95
Abstract

Abstract Recently, biometric recognition has become a significant field of research. The concept of cancelable biometrics (CB) has been introduced to address security concerns related to the handling of sensitive data. In this paper, we address unconstrained face verification by proposing a deep cancelable framework called BiometricNet+ that employs random projections (RP) to conceal face images and compressive sensing (CS) to reconstruct measurements in the original domain. Our lightweight design enforces the properties of unlinkability, revocability, and non-invertibility of the templates while preserving face recognition accuracy. We compare facial features by learning a regularized metric: at training time, we jointly learn facial features and the metric such that matching and non-matching pairs are mapped onto latent target distributions; then, for biometric verification, features are randomly projected via random matrices changed at every enrollment and query and reconstructed before the latent space mapping is computed. We assess the face recognition accuracy of our framework on challenging datasets such as LFW, CALFW, CPLFW, AgeDB, YTF, CFP, and RFW, showing notable improvements over state-of-the-art techniques while meeting the criteria for secure cancelable template design. Since our method requires no fine-tuning of the learned features, it can be applied to pre-trained networks to increase sensitive data protection.

Published
2024
Full Text
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21. The Sixth Data Release of the Radial Velocity Experiment (RAVE). I. Survey Description, Spectra, and Radial Velocities

Author

Alessandro Siviero, Rosemary F. G. Wyse, Kristin Fiegert, Amina Helmi, Teresa Antoja, George M. Seabroke, Ortwin Gerhard, Ivan Minchev, William J. Chaplin, Andrea Kunder, Borja Anguiano, Alejandra Recio-Blanco, Savita Mathur, Matthias Steinmetz, Giacomo Monari, Cristina Chiappini, Benoit Mosser, Guillaume Guiglion, Paul Cass, Jennifer Wojno, Warren A. Reid, Olivier Bienaymé, M. Stupar, J. P. Fulbright, Quentin A. Parker, Benoit Famaey, Kseniia Sysoliatina, Andreas Ritter, James Binney, Diego Bossini, Harry Enke, Rafael A. García, Kenneth C. Freeman, Paula Jofre, Gal Matijevic, Andreas Just, Andrea Miglio, Joss Bland-Hawthorn, G. R. Ruchti, Danijela Birko, Georges Kordopatis, Gerard Gilmore, Friedrich Anders, Fred Watson, Ulisse Munari, Sanjib Sharma, Marica Valentini, Eva K. Grebel, Arnaud Siebert, Thaíse S. Rodrigues, Ralf-Dieter Scholz, Yvonne Elsworth, I. Carrillo, Luca Casagrande, Julio F. Navarro, Mary E K Williams, D. Burton, Brad K. Gibson, Albert Bijaoui, Patrick de Laverny, Tomaž Zwitter, Paul J. McMillan, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Leibniz Institute for Astrophysics Potsdam, Australian Astronomical Observatory, Australian National University, Australian Research Council, Agence Nationale de la Recherche (France), German Research Foundation, European Research Council, Istituto Nazionale di Astrofisica, Johns Hopkins University, National Science Foundation (US), W. M. Keck Foundation, Macquarie University, Netherlands Research School for Astronomy, Natural Sciences and Engineering Research Council of Canada, Slovenian Research Agency, Swiss National Science Foundation, Science and Technology Facilities Council (UK), Opticon, Observatoire Astronomique de Strasbourg, University of Basel, University of Groningen, University of Heidelberg, University of Sydney, Centre National D'Etudes Spatiales (France), Ministerio de Economía y Competitividad (España), Kavli Institute for Theoretical Physics, Simons Foundation, Astronomy, Matthias Steinmetz, Gal Matijevic, Harry Enke, Tomaz Zwitter, Guillaume Guiglion, McMillan, {Paul J.}, Georges Kordopati, Marica Valentini, Cristina Chiappini, Luca Casagrande, Jennifer Wojno, Borja Anguiano, Olivier Bienayme, Albert Bijaoui, James Binney, Donna Burton, Paul Ca, Laverny, {Patrick de}, Kristin Fiegert, Kenneth Freeman, Fulbright, {Jon P.}, Gibson, {Brad K.}, Gerard Gilmore, Grebel, {Eva K.}, Amina Helmi, Andrea Kunder, Ulisse Munari, Navarro, {Julio F.}, Quentin Parker, Ruchti, {Gregory R.}, Alejandra Recio-Blanco, Warren Reid, Seabroke, {George M.}, Alessandro Siviero, Arnaud Siebert, Milorad Stupar, Fred Watson, Williams, {Mary E. K.}, Wyse, {Rosemary F. G.}, Friedrich Ander, Teresa Antoja, Danijela Birko, Joss Bland-Hawthorn, Diego Bossini, Garcia, {Rafael A.}, Ismael Carrillo, Chaplin, {William J.}, Yvonne Elsworth, Benoit Famaey, Ortwin Gerhard, Paula Jofre, Andreas Just, Savita Mathur, Andrea Miglio, Ivan Minchev, Giacomo Monari, Benoit Mosser, Andreas Ritter, Rodrigues, {Thaise S.}, Ralf-Dieter Scholz, Sanjib Sharma, and Kseniia Sysoliatina

Subjects
010504 meteorology & atmospheric sciences, FOS: Physical sciences, Library science, Surveys, Sky surveys, 01 natural sciences, Milky Way Galaxy, Observatory, 0103 physical sciences, PHOTOMETRY, FIELD, Stellar populations, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Milky Way dynamics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], GALAH SURVEY, European research, Astronomy and Astrophysics, Catalogues, Astrophysics - Astrophysics of Galaxies, Galaxy stellar content, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Research council, Astrophysics of Galaxies (astro-ph.GA), LIBRARY, Christian ministry, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, EXPERIMENT RAVE, SKY SURVEY, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Data release, SYSTEM
Abstract

The Radial Velocity Experiment (Rave) is a magnitude-limited (9 < I < 12) spectroscopic survey of Galactic stars randomly selected in Earth's southern hemisphere. The Rave medium-resolution spectra (R ∼ 7500) cover the Ca-triplet region (8410-8795 Å). The sixth and final data release (DR6) is based on 518,387 observations of 451,783 unique stars. Rave observations were taken between 2003 April 12 and 2013 April 4. Here we present the genesis, setup, and data reduction of Rave as well as wavelength-calibrated and flux-normalized spectra and error spectra for all observations in Rave DR6. Furthermore, we present derived spectral classification and radial velocities for the Rave targets, complemented by cross-matches with Gaia DR2 and other relevant catalogs. A comparison between internal error estimates, variances derived from stars with more than one observing epoch, and a comparison with radial velocities of Gaia DR2 reveals consistently that 68% of the objects have a velocity accuracy better than 1.4 km s-1, while 95% of the objects have radial velocities better than 4.0 km s-1. Stellar atmospheric parameters, abundances and distances are presented in a subsequent publication. The data can be accessed via the Rave website (http://rave-survey.org) or the Vizier database., Funding for Rave has been provided by: the Leibniz-Institut f¨ur Astrophysik Potsdam (AIP); the Australian Astronomical Observatory; the Australian National University; the Australian Research Council; the French National Research Agency (Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU with INP and IN2P3, co-funded by CEA and CNES); the German Research Foundation (SPP 1177 and SFB 881); the European Research Council (ERC-StG 240271 Galactica); the Istituto Nazionale di Astrofisica at Padova; The Johns Hopkins University; the National Science Foundation of the USA (AST-0908326); the W. M. Keck foundation; the Macquarie University; the Netherlands Research School for Astronomy; the Natural Sciences and Engineering Research Council of Canada; the Slovenian Research Agency (research core funding no. P1-0188); the Swiss National Science Foundation; the Science & Technology Facilities Council of the UK; Opticon; Strasbourg Observatory; and the Universities of Basel, Groningen, Heidelberg, and Sydney. PJM is supported by grant 2017-03721 from the Swedish Research Council. LC is the recipient of the ARC Future Fellowship FT160100402. RAG acknowledges the support from the PLATO CNES grant. SM would like to acknowledge support from the Spanish Ministry with the Ramon y Cajal fellowship number RYC-2015-17697. MS thanks the Research School of Astronomy & Astrophysics in Canberra for support through a Distinguished Visitor Fellowship. RFGW thanks the Kavli Institute for Theoretical Physics and the Simons Foundation for support as a Simons Distinguished Visiting Scholar. This research was supported in part by the National Science Foundation under Grant No. NSF PHY-1748958 to KITP.

Published
2020

22. Chronos - take the pulse of our galactic neighbourhood. After Gaia: Time domain information, masses and ages for stars

Author

Sébastien Deheuvels, Kevin Belkacem, T. L. Campante, Jérôme Ballot, Victor Silva Aguirre, D. Katz, B. Mosser, Andy Moya, Margarida S. Cunha, Hans Kjeldsen, Misha Haywood, Juan Carlos Suárez, Benoit Famaey, Rafael A. García, Mário J. P. F. G. Monteiro, R. Samadi, Eric Michel, Andrea Miglio, Michel E., Haywood M., Famaey B., Mosser B., Samadi R., Monteiro M.J.P.F.G., Kjeldsen H., Belkacem K., Miglio A., Garcia R., Katz D., Suarez J.C., Deheuvels S., Campante T., Cunha M., Aguirre V.S., Ballot J., and Moya A.

Subjects
Red giant, Computer science, Milky Way, Milky way galaxy, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Stellar age estimation, Observatory, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Seismology, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Time domain astrophysics, Galaxy, Stars, Stellar ages, Stellar age, 13. Climate action, Space and Planetary Science, Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics
Abstract

Understanding our Galaxy’s structure, formation, and evolution will, over the next decades, continue to benefit from the wonderful large survey by Gaia, for astrometric, kinematic, and spectroscopic characterization, and by large spectroscopic surveys for chemical characterization. The weak link for full exploitation of these data is age characterization, and stellar age estimation relies predominantly on mass estimates. The ideas presented in this White Paper shows that a seismology survey is the way out of this situation and a natural complement to existing and planned surveys. These ideas are strongly rooted in the past decade’s experience of the so-called Seismology revolution, initiated with CoRoT and Kepler. The case of red giant stars is used here as the best current illustration of what we can expect from seismology for large samples, but premises for similar developments exist in various other classes of stars covering other ranges of age or mass. Whatever the star considered, the first information provided by stellar pulsations is always related to the mean density and thus to the mass (and age). In order to satisfy the need for long-duration and allsky coverage, we rely on a new instrumental concept which decouples integration time and sampling time. We thus propose a long (~1 year) all-sky survey which would perfectly fit between TESS, PLATO, and the Rubin Observatory (previously known as LSST) surveys to offer a time domain complement to the current and planned astrometric and spectroscopic surveys. The fine characterization of host stars is also a key aspect for the interpretation and exploitation of the various projects – anticipated in the framework of the Voyage 2050 programme – searching for atmospheric characterization of terrestrial planets or, more specifically, looking for a signature of life, in distant planets.

Published
2021

23. Deciphering the evolution of the Milky Way discs: Gaia APOGEE Kepler giant stars and the Besan\c{c}on Galaxy Model

Author

J. Montillaud, Nadège Lagarde, N. Cabral, R. Mor, Francesca Figueras, Cristina Chiappini, Friedrich Anders, Andrea Miglio, Céline Reylé, M. Romero-Gómez, Olivier Bienaymé, J.-B. Salomon, David Cornu, Teresa Antoja, Annie C. Robin, Caroline Soubiran, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de Science des Matériaux de Mulhouse (IS2M), Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Oregon Health and Science University [Portland] (OHSU), Université de Paris - École de sages-femmes Baudelocque (UP ESF Baudelocque), Université de Paris (UP), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Leibniz-Institut für Astrophysik Potsdam (AIP), Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), University of Birmingham [Birmingham], Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Racah Institute of Physics (Racah Institute of Physics), The Hebrew University of Jerusalem (HUJ)-Racah Institute of Physics, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, and N. Lagarde, C. Reylé, C. Chiappini, R. Mor, F. Anders, F. Figueras, A. Miglio, M. Romero-Gómez, T. Antoja, N. Cabral, J.-B. Salomon, A.C. Robin, O. Bienaymé, C. Soubiran, D. Cornu, J. Montillaud

Subjects
Stellar population, Metallicity, Milky Way, Population, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Asteroseismology, evolution [Galaxy], 0103 physical sciences, Galaxy formation and evolution, stellar content [Galaxy], education, 010303 astronomy & astrophysics, Galaxy: structure, Astrophysics::Galaxy Astrophysics, Physics, Galaxy: evolution, [PHYS]Physics [physics], education.field_of_study, Galaxy: stellar content, 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrometry, kinematics and dynamics [Galaxy], Astrophysics - Astrophysics of Galaxies, Galaxy, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Galaxy: kinematics and dynamic, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Galaxy: kinematics and dynamics, structure [Galaxy]
Abstract

[Context] Thanks to ongoing efforts to compute accurate stellar ages, we are able to characterise stars in different regions of the Milky Way. The Gaia and Kepler space-missions, along with ground-based spectroscopic surveys such as APOGEE, provide a unique way to study the chemo-kinematics relations as a function of age through the Galactic stellar populations and provide new constraints to Galactic evolution models. [Aims] We investigate the properties of the double sequences of the Milky Way discs visible in the [α/Fe] versus [Fe/H] diagram, which are usually associated to the chemical thin and thick discs at the solar circle. In the framework of Galactic formation and evolution, we discuss the complex relationships between age, metallicity, [α/Fe], and the radial, azimuthal, and vertical components of the space velocities. [Methods] We study stars with measured chemical and seismic properties from the APOGEE spectroscopic survey and the Kepler satellite, respectively. In addition, astrometry from the Gaia satellite is available for the majority of the sample. We separate the [α/Fe]-[Fe/H] diagram into three stellar populations: the thin disc, the high-α metal-poor thick disc, and the high-α metal-rich thick disc and characterise each of these in the age-chemo-kinematics parameter space. Because of the model-dependent nature of the ages inferred from asteroseismology, and because they depend on the quality of the input spectroscopic information, we compare results obtained from different APOGEE data releases (DR14 and DR16). We also use age determinations from two recent works in the literature. In addition, we use the Besançon stellar populations synthesis model to highlight selection biases and mechanisms (such as mergers and secular evolution) not included in the model. [Results] The thin disc exhibits a flat age-metallicity relation while [α/Fe] increases with stellar age. We confirm no correlation between radial and vertical velocities with [Fe/H], [α/Fe], and age for each stellar population. Considering both samples, Vφ decreases with age for the thin disc, while Vφ increases with age for the high-α metal-poor thick disc. We show that this difference is not due to sample selection. Although the age distribution of the high-α metal-rich thick disc is very close to that of the high-α metal-poor thick disc between 7 and 14 Gyr, its kinematics seems to follow that of the thin disc. This feature, not predicted by the hypotheses included in the Besançon Galaxy Model, suggests a different origin and history for this population. Finally, we show that there is a maximum dispersion of the vertical velocity, σZ, with age for the high-α metal-poor thick disc around 8 Gyr. The comparisons with the Besançon Galaxy Model simulations suggest a more complex chemo-dynamical scheme to explain this feature, most likely including mergers and radial migration effects., F.F., A.F., R.M., M.R., T.A. acknowledge support by the Spanish Ministry of Science, Innovation and University (MICIU/FEDER, UE) through grant RTI2018-095076-B-C21, the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia “María de Maeztu”) through grant CEX2019-000918-M, the Ramon y Cajal Fellowship RYC2018-025968-I. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 800502. AM acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 772293 – project ASTEROCHRONOMETRY, https://www.asterochronometry.eu.

Published
2021

24. Sensitivity of low-degree solar p modes to active and ephemeral regions: frequency shifts back to the Maunder minimum

Author

Raphaëlle D. Haywood, Andrea Miglio, Rachel Howe, Steven J. Hale, Yvonne Elsworth, Sarbani Basu, Eddie Ross, William J. Chaplin, Timothy Milbourne, and Guy R. Davies

Subjects
OSCILLATION FREQUENCIES, 010504 meteorology & atmospheric sciences, Field (physics), FOS: Physical sciences, Flux, MAGNETIC ACTIVITY, Astrophysics, 01 natural sciences, 0103 physical sciences, TOTAL IRRADIANCE, Astrophysics::Solar and Stellar Astrophysics, activity [Sun], helioseismology [Sun], CYCLE, FIELD, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, oscillations [Sun], Ephemeral key, SUN, Astronomy and Astrophysics, Magnetic flux, Magnetic field, Maxima and minima, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Maxima
Abstract

We explore the sensitivity of the frequencies of low-degree solar p-modes to near-surface magnetic flux on different spatial scales and strengths, specifically to active regions with strong magnetic fields and ephemeral regions with weak magnetic fields. We also use model reconstructions from the literature to calculate average frequency offsets back to the end of the Maunder minimum. We find that the p-mode frequencies are at least three times less sensitive (at 95% confidence) to the ephemeral-region field than they are to the active-region field. Frequency shifts between activity cycle minima and maxima are controlled predominantly by the change of active region flux. Frequency shifts at cycle minima (with respect to a magnetically quiet Sun) are determined largely by the ephemeral flux, and are estimated to have been $0.1\,\rm \mu Hz$ or less over the last few minima. We conclude that at epochs of cycle minimum, frequency shifts due to near-surface magnetic activity are negligible compared to the offsets between observed and model frequencies that arise from inaccurate modelling of the near-surface layers (the so-called surface term). The implication is that this will be the case for other Sun-like stars with similar activity, which has implications for asteroseismic modelling of stars., Comment: 5 pages, 3 figures, accepted for publication in Letters of Monthly Notices of the Royal Astronomical Society

Published
2019

25. KOI-3890: a high-mass-ratio asteroseismic red giant+M-dwarf eclipsing binary undergoing heartbeat tidal interactions

Author

Tiago L. Campante, James S. Kuszlewicz, Sébastien Deheuvels, Guy R. Davies, Allyson Bieryla, Thomas S. H. North, Keaton J. Bell, Saskia Hekker, Andrea Miglio, William J. Chaplin, David W. Latham, Mikkel N. Lund, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Orbital plane, Red giant, fundamental parameters [stars], FOS: Physical sciences, KEPLER, asteroseismology, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Asteroseismology, photometric [techniques], Photometry (optics), techniques: photometric, eclipsing [binaries], SYSTEMS, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, stars: evolution, Binary system, MAIN-SEQUENCE, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, LIGHT CURVES, Physics, STAR, 010308 nuclear & particles physics, Stellar rotation, binaries: eclipsing, Astronomy and Astrophysics, Mass ratio, EXOPLANETS, Radial velocity, ALIGNMENT, SPIN, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, evolution [stars], High Energy Physics::Experiment, stars: fundamental parameters, Astrophysics::Earth and Planetary Astrophysics, SOLAR-LIKE OSCILLATIONS, MULTISITE CAMPAIGN
Abstract

KOI-3890 is a highly eccentric, 153-day period eclipsing, single-lined spectroscopic binary system containing a red-giant star showing solar-like oscillations alongside tidal interactions. The combination of transit photometry, radial velocity observations, and asteroseismology have enabled the detailed characterisation of both the red-giant primary and the M-dwarf companion, along with the tidal interaction and the geometry of the system. The stellar parameters of the red-giant primary are determined through the use of asteroseismology and grid-based modelling to give a mass and radius of $M_{\star}=1.04\pm0.06\;\textrm{M}_{\odot}$ and $R_{\star}=5.8\pm0.2\;\textrm{R}_{\odot}$ respectively. When combined with transit photometry the M-dwarf companion is found to have a mass and radius of $M_{\mathrm{c}}=0.23\pm0.01\;\textrm{M}_{\odot}$ and $R_{\mathrm{c}}=0.256\pm0.007\;\textrm{R}_{\odot}$. Moreover, through asteroseismology we constrain the age of the system through the red-giant primary to be $9.1^{+2.4}_{-1.7}\;\mathrm{Gyr}$. This provides a constraint on the age of the M-dwarf secondary, which is difficult to do for other M-dwarf binary systems. In addition, the asteroseismic analysis yields an estimate of the inclination angle of the rotation axis of the red-giant star of $i=87.6^{+2.4}_{-1.2}$ degrees. The obliquity of the system\textemdash the angle between the stellar rotation axis and the angle normal to the orbital plane\textemdash is also derived to give $\psi=4.2^{+2.1}_{-4.2}$ degrees showing that the system is consistent with alignment. We observe no radius inflation in the M-dwarf companion when compared to current low-mass stellar models., Comment: 11 pages, 5 figures, accepted for publication in MNRAS

Published
2019

26. Impact of magnetic activity on inferred stellar properties of main sequence Sun-like stars

Author

Alexandra E. L. Thomas, Sarbani Basu, Andrea Miglio, William J. Chaplin, Guy R. Davies, B. M. Rendle, Thomas A.E.L., Chaplin W.J., Basu S., Rendle B., Davies G., and Miglio A.

Subjects
fundamental parameters [stars], FOS: Physical sciences, Field strength, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, asteroseismology, Spatial distribution, 01 natural sciences, Asteroseismology, Frequency separation, 0103 physical sciences, stars: activity, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, activity [stars], 010308 nuclear & particles physics, Oscillation, Mode (statistics), Astronomy and Astrophysics, Observable, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, stars: fundamental parameters, Astrophysics::Earth and Planetary Astrophysics
Abstract

The oscillation frequencies observed in Sun-like stars are susceptible to being shifted by magnetic activity effects. The measured shifts depend on a complex relationship involving the mode type, the field strength and spatial distribution of activity, as well as the inclination angle of the star. Evidence of these shifts is also present in frequency separation ratios which are often used when inferring global properties of stars in order to avoid surface effects. However, one assumption when using frequency ratios for this purpose is that there are no near-surface perturbations that are non-spherically symmetric. In this work, we studied the impact on inferred stellar properties when using frequency ratios that are influenced by non-homogeneous activity distributions. We generate several sets of artificial oscillation frequencies with various amounts of shift and determine stellar properties using two separate pipelines. We find that for asteroseismic observations of Sun-like targets we can expect magnetic activity to affect mode frequencies which will bias the results from stellar modelling analysis. Although for most stellar properties this offset should be small, typically less than 0.5% in mass, estimates of age and central hydrogen content can have an error of up to 5% and 3% respectively. We expect a larger frequency shift and therefore larger bias for more active stars. We also warn that for stars with very high or low inclination angles, the response of modes to activity is more easily observable in the separation ratios and hence will incur a larger bias., 13 pages, 8 figures

Published
2021

27. On the impact of the structural surface effect on global stellar properties and asteroseismic analyses

Author

Richard Scuflaire, George C. Angelou, Andrea Miglio, Achim Weiss, Arlette Noels, Jakob Rørsted Mosumgaard, Victor Silva Aguirre, Andreas Christ Sølvsten Jørgensen, Josefina Montalbán, Jorgensen A.C.S., Montalban J., Angelou G.C., Miglio A., Weiss A., Scuflaire R., Noels A., Mosumgaard J.R., and Aguirre V.S.

Subjects
Monte Carlo method, statistical [methods], FOS: Physical sciences, Stratification (water), asteroseismology, stars: interiors, 01 natural sciences, Asteroseismology, stars: atmosphere, Mixing length model, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Stellar structure, Boundary value problem, Statistical physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, atmospheres [stars], interiors [stars], methods: statistical, 010308 nuclear & particles physics, Astronomy and Astrophysics, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics
Abstract

In a series of papers, we have recently demonstrated that it is possible to construct stellar structure models that robustly mimic the stratification of multi-dimensional radiative magneto-hydrodynamic simulations at every time-step of the computed evolution. The resulting models offer a more realistic depiction of the near-surface layers of stars with convective envelopes than parameterizations, such as mixing length theory, do. In this paper, we explore how this model improvement impacts on seismic and non-seismic properties of stellar models across the Hertzsprung-Russell diagram. We show that the improved description of the outer boundary layers alters the predicted global stellar properties at different evolutionary stages. In a hare and hound exercise, we show that this plays a key role for asteroseismic analyses, as it, for instance, often shifts the inferred stellar age estimates by more than 10 per cent. Improper boundary conditions may thus introduce systematic errors that exceed the required accuracy of the PLATO space mission. Moreover, we discuss different approximations for how to compute stellar oscillation frequencies. We demonstrate that the so-called gas $\Gamma_1$ approximation performs reasonably well for all main-sequence stars. Using a Monte Carlo approach, we show that the model frequencies of our hybrid solar models are consistent with observations within the uncertainties of the global solar parameters when using the so-called reduced $\Gamma_1$ approximation., Comment: Submitted to MNRAS

Published
2021

28. Age dissection of the Milky Way discs: Red giants in the Kepler field

Author

Andrea Miglio, Diego Bossini, Saniya Khan, Guy R. Davies, Luca Casagrande, Cristina Chiappini, Thaíse S. Rodrigues, Karsten Brogaard, Arlette Noels, B. Mosser, Rob Izzard, William J. Chaplin, L. Girardi, J. T. Mackereth, Ilya Mandel, Fiorenzo Vincenzo, Josefina Montalbán, Marica Valentini, Daisuke Kawata, Miglio A., Chiappini C., MacKereth J.T., Davies G.R., Brogaard K., Casagrande L., Chaplin W.J., Girardi L., Kawata D., Khan S., Izzard R., Montalban J., Mosser B., Vincenzo F., Bossini D., Noels A., Rodrigues T., Valentini M., and Mandel I.

Subjects
Stellar mass, Metallicity, Mass-loss [Stars], Stars: Mass-loss, FOS: Physical sciences, Stellar content [Galaxy], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Galaxy: Structure, Late-type [Stars], Galaxy: Evolution, Structure [Galaxy], 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Stars: Late-type, 010303 astronomy & astrophysics, Red clump, Stellar evolution, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Star formation, Asteroseismology, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Galaxy: Stellar content, Stars, Evolution [Galaxy], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Open cluster
Abstract

[Abridged] Ensemble studies of red-giant stars with exquisite asteroseismic, spectroscopic, and astrometric constraints offer a novel opportunity to recast and address long-standing questions concerning the evolution of stars and of the Galaxy. Here, we infer masses and ages for nearly 5400 giants with available Kepler light curves and APOGEE spectra, and discuss some of the systematics that may affect the accuracy of the inferred stellar properties. First, we look at age-chemical-abundances relations. We find a dearth of young, metal-rich stars, and the existence of a significant population of old (8-9 Gyr), low-[$\alpha$/Fe], super-solar metallicity stars, reminiscent of the age and metallicity of the well-studied open cluster NGC6791. The age-chemo-kinematic properties of these stars indicate that efficient radial migration happens in the thin disk. We find that ages and masses of the nearly 400 $\alpha$-element-rich red-giant-branch (RGB) stars in our sample are compatible with those of an old (~11 Gyr), nearly coeval, chemical-thick disk population. Using a statistical model, we show that 95% of the population was born within ~1.5 Gyr. Moreover, we find a difference in the vertical velocity dispersion between low- and high-[$\alpha$/Fe] populations, confirming their different chemo-dynamical histories. We then exploit the almost coeval $\alpha$-rich population to gain insight into processes that may have altered the mass of a star along its evolution, which are key to improve the mapping of the observed stellar mass to age. We find evidence for a mean integrated RGB mass loss = 0.10 $\pm$ 0.02 Msun and that the occurrence of massive (M $\gtrsim$ 1.1 Msun) $\alpha$-rich stars is of the order of 5% on the RGB, and significantly higher in the RC, supporting the scenario in which most of these stars had undergone interaction with a companion., Comment: accepted for publication in A&A, 26 pages, 24 figures, catalogue available via cds

Published
2021

29. Prospects for Galactic and stellar astrophysics with asteroseismology of giant stars in the TESS continuous viewing zones and beyond

Author

Jennifer L. van Saders, Léo Girardi, Johanna Teske, Emma Willett, Dennis Stello, Tiago L. Campante, M. Vrard, William J. Chaplin, Marc H. Pinsonneault, Savita Mathur, Andreas Christ Sølvsten Jørgensen, Paul G. Beck, Andrea Miglio, Martin Bo Nielsen, B. Mosser, Aldo Serenelli, Thaíse S. Rodrigues, Rafael A. García, Maria Bergemann, Josefina Montalbán, Jamie Tayar, Oliver J. Hall, Sarbani Basu, Luca Casagrande, Domenico Nardiello, Yvonne Elsworth, Rachael L. Beaton, Saniya Khan, Warrick H. Ball, Christina Chiappini, Victor Silva Aguirre, J. Ted Mackereth, Diego Bossini, Government of Canada, University of Toronto, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Australian Research Council, Generalitat de Catalunya, National Aeronautics and Space Administration (US), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Mackereth, Ted, Miglio, Andrea, Elsworth, Yvonne, Mosser, Benoit, Mathur, Savita, Garcia, Rafael A, Nardiello, Domenico, Hall, Oliver J, Vrard, Mathieu, Ball, Warrick H, Basu, Sarbani, Beaton, Rachael L, Beck, Paul G, Bergemann, Maria, Bossini, Diego, Casagrande, Luca, Campante, Tiago L, Chaplin, William J, Chiappini, Cristina, Girardi, Léo, Jørgensen, Andreas Christ Sølvsten, Khan, Saniya, Montalbán, Josefina, Nielsen, Martin B, Pinsonneault, Marc H, Rodrigues, Thaíse S, Serenelli, Aldo, Silva Aguirre, Victor, Stello, Denni, Tayar, Jamie, Teske, Johanna, van Saders, Jennifer L, and Willett, Emma

Subjects
Red giant, Star (game theory), Milky Way, oscillations [Stars], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Asteroseismology, fundamental parameters [Stars], 0103 physical sciences, Stars: oscillations, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, stellar content [Galaxy], 010303 astronomy & astrophysics, Galaxy: structure, Astrophysics::Galaxy Astrophysics, Stars: fundamental parameters, Physics, Galaxy: stellar content, stars: oscillation, 010308 nuclear & particles physics, Star formation, Galaxy: fundamental parameter, fundamental parameters [Galaxy], Astronomy and Astrophysics, stars: fundamental parameter, Galaxy: fundamental parameters, kinematics and dynamics [Galaxy], Giant star, Astrophysics - Astrophysics of Galaxies, Stars, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Galaxy: kinematics and dynamic, Astrophysics::Earth and Planetary Astrophysics, Galaxy: kinematics and dynamics, structure [Galaxy]
Abstract

Mackereth, J. Ted, et al., The NASA Transiting Exoplanet Survey Satellite (NASA-TESS) mission presents a treasure trove for understanding the stars it observes and the Milky Way, in which they reside. We present a first look at the prospects for Galactic and stellar astrophysics by performing initial asteroseismic analyses of bright (G < 11) red giant stars in the TESS southern continuous viewing zone (SCVZ). Using three independent pipelines, we detect νmax and Δν in 41 per cent of the 15 405 star parent sample (6388 stars), with consistency at a level of ∼2 per cent in νmax and ∼5 per cent in Δν. Based on this, we predict that seismology will be attainable for ∼3 × 105 giants across the whole sky and at least 104 giants with ≥1 yr of observations in the TESS-CVZs, subject to improvements in analysis and data reduction techniques. The best quality TESS-CVZ data, for 5574 stars where pipelines returned consistent results, provide high-quality power spectra across a number of stellar evolutionary states. This makes possible studies of, for example, the asymptotic giant branch bump. Furthermore, we demonstrate that mixed ℓ = 1 modes and rotational splitting are cleanly observed in the 1-yr data set. By combining TESS-CVZ data with TESS-HERMES, SkyMapper, APOGEE, and Gaia, we demonstrate its strong potential for Galactic archaeology studies, providing good age precision and accuracy that reproduces well the age of high [α/Fe] stars and relationships between mass and kinematics from previous studies based on e.g. Kepler. Better quality astrometry and simpler target selection than the Kepler sample makes this data ideal for studies of the local star formation history and evolution of the Galactic disc. These results provide a strong case for detailed spectroscopic follow-up in the CVZs to complement that which has been (or will be) collected by current surveys., JTM and AM acknowledge support from the ERC Consolidator Grant funding scheme (project ASTEROCHRONOMETRY, G.A. n. 772293). JTM acknowledges support from the Banting Postdoctoral Fellowship programme administered by the Government of Canada, and a CITA/Dunlap Institute fellowship. The Dunlap Institute is funded through an endowment established by the David Dunlap family and the University of Toronto. SM acknowledges support from the Spanish Ministry with the Ramon y Cajal fellowship number RYC-2015-17697. RAG acknowledges the support from the PLATO CNES grant. DB acknowledges supported by FCT through the research grants UIDB/04434/2020, UIDP/04434/2020, and PTDC/FIS-AST/30389/2017, and by FEDER – Fundo Europeu de Desenvolvimento Regional through COMPETE2020 – Programa Operacional Competitividade e Internacionalização (grant: POCI-01-0145-FEDER-030389). LC acknowledges support from the Australian Research Council grant FT160100402. TC acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 792848 (PULSATION). AS is partially supported by grants ESP2017-82674-R (Spanish Government) and 2017-SGR-1131 (Generalitat de Catalunya). MHP and MV acknowledge support from NASA grant 80NSSC18K1582.

Published
2021

30. The Sixth Data Release of the Radial Velocity Experiment (R ave). II. Stellar Atmospheric Parameters, Chemical Abundances, and Distances

Author

Savita Mathur, Quentin A. Parker, Diego Bossini, I. Carrillo, Amina Helmi, Cristina Chiappini, Luca Casagrande, Marica Valentini, Paul J. McMillan, Teresa Antoja, Brad K. Gibson, Sanjib Sharma, Kenneth C. Freeman, Benoit Famaey, Andrea Miglio, Harry Enke, Joss Bland-Hawthorn, Rosemary F. G. Wyse, G. R. Ruchti, Georges Kordopatis, George M. Seabroke, Benoit Mosser, Gal Matijevic, Julio F. Navarro, M. Stupar, Fred Watson, Alessandro Siviero, Mary E K Williams, J. P. Fulbright, Gerard Gilmore, Kseniia Sysoliatina, Giacomo Monari, Tomaž Zwitter, Paul Cass, Danijela Birko, Friedrich Anders, Yvonne Elsworth, Eva K. Grebel, Warren A. Reid, Ulisse Munari, Kristin Fiegert, Olivier Bienaymé, Andreas Ritter, Alejandra Recio-Blanco, James Binney, Thaíse S. Rodrigues, Guillaume Guiglion, Arnaud Siebert, Ralf-Dieter Scholz, Patrick de Laverny, Paula Jofre, Andreas Just, D. Burton, Ortwin Gerhard, Jennifer Wojno, Ivan Minchev, William J. Chaplin, Albert Bijaoui, Andrea Kunder, Borja Anguiano, Rafael A. García, Matthias Steinmetz, Leibniz Institute for Astrophysics Potsdam, Australian Astronomical Observatory, Australian National University, Australian Research Council, Agence Nationale de la Recherche (France), German Research Foundation, European Research Council, Istituto Nazionale di Astrofisica, Johns Hopkins University, National Science Foundation (US), W. M. Keck Foundation, Macquarie University, Netherlands Research School for Astronomy, Natural Sciences and Engineering Research Council of Canada, Slovenian Research Agency, Swiss National Science Foundation, Science and Technology Facilities Council (UK), Opticon, Observatoire Astronomique de Strasbourg, University of Basel, University of Groningen, University of Heidelberg, University of Sydney, Centre National D'Etudes Spatiales (France), Ministerio de Economía y Competitividad (España), Kavli Institute for Theoretical Physics, Simons Foundation, Steinmetz M., Guiglion G., McMillan P.J., Matijevic G., Enke H., Kordopatis G., Zwitter T., Valentini M., Chiappini C., Casagrande L., Wojno J., Anguiano B., Bienayme O., Bijaoui A., Binney J., Burton D., Cass P., De Laverny P., Fiegert K., Freeman K., Fulbright J.P., Gibson B.K., Gilmore G., Grebel E.K., Helmi A., Kunder A., Munari U., Navarro J.F., Parker Q., Ruchti G.R., Recio-Blanco A., Reid W., Seabroke G.M., Siviero A., Siebert A., Stupar M., Watson F., Williams M.E.K., Wyse R.F.G., Anders F., Antoja T., Birko D., Bland-Hawthorn J., Bossini D., Garcia R.A., Carrillo I., Chaplin W.J., Elsworth Y., Famaey B., Gerhard O., Jofre P., Just A., Mathur S., Miglio A., Minchev I., Monari G., Mosser B., Ritter A., Rodrigues T.S., Scholz R.-D., Sharma S., Sysoliatina K., Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Astronomy

Subjects
010504 meteorology & atmospheric sciences, ACCURACY, FOS: Physical sciences, Library science, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, surveys, Observatory, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, KINEMATICS, Abundances, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, F-DWARF, European research, Surveys - Stars, Astronomy and Astrophysics, DISC, Astrophysics - Astrophysics of Galaxies, Distances, Astrophysics - Solar and Stellar Astrophysics, stars: abundances - distances, 13. Climate action, Space and Planetary Science, Research council, Astrophysics of Galaxies (astro-ph.GA), PATTERN SPEED, MILKY, Christian ministry, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, EXPERIMENT RAVE, SKY SURVEY, Data release, STARS, ISOCHRONES
Abstract

We present part 2 of the sixth and final Data Release (DR6) of the Radial Velocity Experiment (Rave), a magnitude-limited spectroscopic survey of Galactic stars randomly selected in Earth's southern hemisphere. The Rave medium-resolution spectra (R ∼ 7500) cover the Ca triplet region (8410-8795 Å) and span the complete time frame from the start of Rave observations on 2003 April 12 to their completion on 2013 April 4. In the second of two publications, we present the data products derived from 518,387 observations of 451,783 unique stars using a suite of advanced reduction pipelines focusing on stellar atmospheric parameters, in particular purely spectroscopically derived stellar atmospheric parameters, and the overall metallicity), enhanced stellar atmospheric parameters inferred via a Bayesian pipeline using Gaia DR2 astrometric priors, and asteroseismically calibrated stellar atmospheric parameters for giant stars based on asteroseismic observations for 699 K2 stars. In addition, we provide abundances of the elements Fe, Al, and Ni, as well as an overall [α/Fe] ratio obtained using a new pipeline based on the GAUGUIN optimization method that is able to deal with variable signal-to-noise ratios. The Rave DR6 catalogs are cross-matched with relevant astrometric and photometric catalogs, and are complemented by orbital parameters and effective temperatures based on the infrared flux method. The data can be accessed via the Rave website (http://rave-survey.org) or the Vizier database., Funding for Rave has been provided by: the Leibniz-Institut f¨ur Astrophysik Potsdam (AIP); the Australian Astronomical Observatory; the Australian National University; the Australian Research Council; the French National Research Agency (Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU with INP and IN2P3, co-funded by CEA and CNES); the German Research Foundation (SPP 1177 and SFB 881); the European Research Council (ERC-StG 240271 Galactica); the Istituto Nazionale di Astrofisica at Padova; The Johns Hopkins University; the National Science Foundation of the USA (AST-0908326); the W. M. Keck foundation; the Macquarie University; the Netherlands Research School for Astronomy; the Natural Sciences and Engineering Research Council of Canada; the Slovenian Research Agency (research core funding no. P1-0188); the Swiss National Science Foundation; the Science & Technology Facilities Council of the UK; Opticon; Strasbourg Observatory; and the Universities of Basel, Groningen, Heidelberg, and Sydney. PJM is supported by grant 2017-03721 from the Swedish Research Council. LC is the recipient of the ARC Future Fellowship FT160100402. RAG acknowledges the support from the PLATO CNES grant. SM would like to acknowledge support from the Spanish Ministry with the Ramon y Cajal fellowship number RYC-2015-17697. MS thanks the Research School of Astronomy & Astrophysics in Canberra for support through a Distinguished Visitor Fellowship. RFGW thanks the Kavli Institute for Theoretical Physics and the Simons Foundation for support as a Simons Distinguished Visiting Scholar. This research was supported in part by the National Science Foundation under Grant No. NSF PHY-1748958 to KITP.

Published
2020

31. The 16th Data Release of the Sloan Digital Sky Surveys : First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra

Author

Romina Ahumada, Carlos Allende Prieto, Andrés Almeida, Friedrich Anders, Scott F. Anderson, Brett H. Andrews, Borja Anguiano, Riccardo Arcodia, Eric Armengaud, Marie Aubert, Santiago Avila, Vladimir Avila-Reese, Carles Badenes, Christophe Balland, Kat Barger, Jorge K. Barrera-Ballesteros, Sarbani Basu, Julian Bautista, Rachael L. Beaton, Timothy C. Beers, B. Izamar T. Benavides, Chad F. Bender, Mariangela Bernardi, Matthew Bershady, Florian Beutler, Christian Moni Bidin, Jonathan Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Médéric Boquien, Jura Borissova, Jo Bovy, W. N. Brandt, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Martin Bureau, Adam Burgasser, Etienne Burtin, Mariana Cano-Díaz, Raffaella Capasso, Michele Cappellari, Ricardo Carrera, Solène Chabanier, William Chaplin, Michael Chapman, Brian Cherinka, Cristina Chiappini, Peter Doohyun Choi, S. Drew Chojnowski, Haeun Chung, Nicolas Clerc, Damien Coffey, Julia M. Comerford, Johan Comparat, Luiz da Costa, Marie-Claude Cousinou, Kevin Covey, Jeffrey D. Crane, Katia Cunha, Gabriele da Silva Ilha, Yu Sophia Dai, Sanna B. Damsted, Jeremy Darling, James W. Davidson, Roger Davies, Kyle Dawson, Nikhil De, Axel de la Macorra, Nathan De Lee, Anna Bárbara de Andrade Queiroz, Alice Deconto Machado, Sylvain de la Torre, Flavia Dell’Agli, Hélion du Mas des Bourboux, Aleksandar M. Diamond-Stanic, Sean Dillon, John Donor, Niv Drory, Chris Duckworth, Tom Dwelly, Garrett Ebelke, Sarah Eftekharzadeh, Arthur Davis Eigenbrot, Yvonne P. Elsworth, Mike Eracleous, Ghazaleh Erfanianfar, Stephanie Escoffier, Xiaohui Fan, Emily Farr, José G. Fernández-Trincado, Diane Feuillet, Alexis Finoguenov, Patricia Fofie, Amelia Fraser-McKelvie, Peter M. Frinchaboy, Sebastien Fromenteau, Hai Fu, Lluís Galbany, Rafael A. Garcia, D. A. García-Hernández, Luis Alberto Garma Oehmichen, Junqiang Ge, Marcio Antonio Geimba Maia, Doug Geisler, Joseph Gelfand, Julian Goddy, Violeta Gonzalez-Perez, Kathleen Grabowski, Paul Green, Catherine J. Grier, Hong Guo, Julien Guy, Paul Harding, Sten Hasselquist, Adam James Hawken, Christian R. Hayes, Fred Hearty, S. Hekker, David W. Hogg, Jon A. Holtzman, Danny Horta, Jiamin Hou, Bau-Ching Hsieh, Daniel Huber, Jason A. S. Hunt, J. Ider Chitham, Julie Imig, Mariana Jaber, Camilo Eduardo Jimenez Angel, Jennifer A. Johnson, Amy M. Jones, Henrik Jönsson, Eric Jullo, Yerim Kim, Karen Kinemuchi, Charles C. Kirkpatrick IV, George W. Kite, Mark Klaene, Jean-Paul Kneib, Juna A. Kollmeier, Hui Kong, Marina Kounkel, Dhanesh Krishnarao, Ivan Lacerna, Ting-Wen Lan, Richard R. Lane, David R. Law, Jean-Marc Le Goff, Henry W. Leung, Hannah Lewis, Cheng Li, Jianhui Lian, Lihwai Lin, Dan Long, Penélope Longa-Peña, Britt Lundgren, Brad W. Lyke, J. Ted Mackereth, Chelsea L. MacLeod, Steven R. Majewski, Arturo Manchado, Claudia Maraston, Paul Martini, Thomas Masseron, Karen L. Masters, Savita Mathur, Richard M. McDermid, Andrea Merloni, Michael Merrifield, Szabolcs Mészáros, Andrea Miglio, Dante Minniti, Rebecca Minsley, Takamitsu Miyaji, Faizan Gohar Mohammad, Benoit Mosser, Eva-Maria Mueller, Demitri Muna, Andrea Muñoz-Gutiérrez, Adam D. Myers, Seshadri Nadathur, Preethi Nair, Kirpal Nandra, Janaina Correa do Nascimento, Rebecca Jean Nevin, Jeffrey A. Newman, David L. Nidever, Christian Nitschelm, Pasquier Noterdaeme, Julia E. O’Connell, Matthew D. Olmstead, Daniel Oravetz, Audrey Oravetz, Yeisson Osorio, Zachary J. Pace, Nelson Padilla, Nathalie Palanque-Delabrouille, Pedro A. Palicio, Hsi-An Pan, Kaike Pan, James Parker, Romain Paviot, Sebastien Peirani, Karla Peña Ramŕez, Samantha Penny, Will J. Percival, Ismael Perez-Fournon, Ignasi Pérez-Ràfols, Patrick Petitjean, Matthew M. Pieri, Marc Pinsonneault, Vijith Jacob Poovelil, Joshua Tyler Povick, Abhishek Prakash, Adrian M. Price-Whelan, M. Jordan Raddick, Anand Raichoor, Amy Ray, Sandro Barboza Rembold, Mehdi Rezaie, Rogemar A. Riffel, Rogério Riffel, Hans-Walter Rix, Annie C. Robin, A. Roman-Lopes, Carlos Román-Zúñiga, Benjamin Rose, Ashley J. Ross, Graziano Rossi, Kate Rowlands, Kate H. R. Rubin, Mara Salvato, Ariel G. Sánchez, Laura Sánchez-Menguiano, José R. Sánchez-Gallego, Conor Sayres, Adam Schaefer, Ricardo P. Schiavon, Jaderson S. Schimoia, Edward Schlafly, David Schlegel, Donald P. Schneider, Mathias Schultheis, Axel Schwope, Hee-Jong Seo, Aldo Serenelli, Arman Shafieloo, Shoaib Jamal Shamsi, Zhengyi Shao, Shiyin Shen, Matthew Shetrone, Raphael Shirley, Víctor Silva Aguirre, Joshua D. Simon, M. F. Skrutskie, Anže Slosar, Rebecca Smethurst, Jennifer Sobeck, Bernardo Cervantes Sodi, Diogo Souto, David V. Stark, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Julianna Stermer, Thaisa Storchi-Bergmann, Alina Streblyanska, Guy S. Stringfellow, Amelia Stutz, Genaro Suárez, Jing Sun, Manuchehr Taghizadeh-Popp, Michael S. Talbot, Jamie Tayar, Aniruddha R. Thakar, Riley Theriault, Daniel Thomas, Zak C. Thomas, Jeremy Tinker, Rita Tojeiro, Hector Hernandez Toledo, Christy A. Tremonti, Nicholas W. Troup, Sarah Tuttle, Eduardo Unda-Sanzana, Marica Valentini, Jaime Vargas-González, Mariana Vargas-Magaña, Jose Antonio Vázquez-Mata, M. Vivek, David Wake, Yuting Wang, Benjamin Alan Weaver, Anne-Marie Weijmans, Vivienne Wild, John C. Wilson, Robert F. Wilson, Nathan Wolthuis, W. M. Wood-Vasey, Renbin Yan, Meng Yang, Christophe Yèche, Olga Zamora, Pauline Zarrouk, Gail Zasowski, Kai Zhang, Cheng Zhao, Gongbo Zhao, Zheng Zheng, Guangtun Zhu, Hu Zou, Department of Physics, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofisica de Canarias (IAC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional Autónoma de México (UNAM), Department of Astrophysical Sciences [Princeton], Princeton University, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Department of Astronomy, Yale University [New Haven], University of Notre Dame [Indiana] (UND), Department of Physics and Astronomy [Philadelphia], University of Pennsylvania [Philadelphia], University of Wisconsin-Madison, Texas Tech University Health Sciences Center, Texas Tech University [Lubbock] (TTU), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), California Institute of Technology (CALTECH), Sub-department of Astrophysics [Oxford], Department of Physics [Oxford], University of Oxford [Oxford]-University of Oxford [Oxford], Center for Astrophysics and Space Sciences [La Jolla] (CASS), University of California [San Diego] (UC San Diego), University of California-University of California, Department of Psychology, St John's University, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Departamento de FisicaTeorica e IFT-UAM/CSIC, Universidad Autonoma de Madrid (UAM), Lowell Observatory [Flagstaff], Observatorio Nacional [Rio de Janeiro], Vernalis (R&D) Ltd, Special Care Dentistry, UCLH Eastman Dental Hospital, University of Utah, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidad de La Laguna [Tenerife - SP] (ULL), University of Virginia [Charlottesville], University of Wyoming (UW), School of Physics and Astronomy, University of Birmingham [Birmingham], Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Arizona State University [Tempe] (ASU), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Max-Planck-Institut für Astronomie (MPIA), Texas Christian University (TCU), Department of Physics and Astronomy [Irvine], University of California [Irvine] (UCI), Department of Physics and Astronomy [Pittsburgh], University of Pittsburgh (PITT), Pennsylvania Commonwealth System of Higher Education (PCSHE)-Pennsylvania Commonwealth System of Higher Education (PCSHE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), New York University [New York] (NYU), NYU System (NYU), Research Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, New Mexico State University, Pennsylvania State University (Penn State), Penn State System, Princess Margaret Hospital, University of Toronto, Cognition, Langues, Langage, Ergonomie (CLLE-ERSS), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Toulouse - Jean Jaurès (UT2J)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), J. A. Baker Institute, Cornell University [New York], Institute of Infection, Immunity & Inflammation, University of Glasgow, Sainsbury Laboratory Cambridge University (SLCU), University of Cambridge [UK] (CAM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Carnegie Observatories, Carnegie Institution for Science [Washington], Institute of Science and Technology [Austria] (IST Austria), Universidad de Atacama, Department of Chemical and Biomolecular Engineering, Universidad de Antofagasta, Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Institute of cosmology and gravitation, University of Portsmouth, Institut d'Astronomie et d'Astrophysique [Bruxelles] (IAA), Université libre de Bruxelles (ULB), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max-Planck-Institut für Astrophysik (MPA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département des Sciences et Gestion de l'Environnement/Océanologie [Liège], Université de Liège, Universidad Andrés Bello [Santiago] (UNAB), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Montana State University (MSU), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Institut Lagrange de Paris, Sorbonne Université (SU), The Wellcome Trust Centre for Human Genetics [Oxford], University of Oxford [Oxford], Liverpool John Moores University (LJMU), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), Chinese Academy of Sciences [Beijing] (CAS), McDonald Observatory, University of Texas at Austin [Austin], Astronomy Centre, University of Sussex, Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], University of Washington [Seattle], Vanderbilt University [Nashville], Stellar Astrophysics Centre [Aarhus] (SAC), University of Colorado [Boulder], Laboratoire de Biochimie Médicale (LBM), CHU Rouen, Normandie Université (NU)-Normandie Université (NU), University of St Andrews [Scotland], Instituto de Astronomıa, universidad catolica del Norte, Institut d'Astrophysique et de Géophysique [Liège], Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Department of Computer Science and Engineering [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Dunlap Institute for Astronomy and Astrophysics [Toronto], World Bank, State Key Laboratory in Computer Science [Beijing] (SKLCS), Institute of Software Chinese Academy of Sciences [Beijing], Nanjing University of Information Science and Technology (NUIST), Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Johns Hopkins University (JHU), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Pennsylvania, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Oxford-University of Oxford, University of California (UC)-University of California (UC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universidad Autónoma de Madrid (UAM), University of Virginia, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), University of California [Irvine] (UC Irvine), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Carnegie Institution for Science, Institute of Science and Technology [Klosterneuburg, Austria] (IST Austria), Harvard University-Smithsonian Institution, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Oxford, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Ahumada R., Prieto C.A., Almeida A., Anders F., Anderson S.F., Andrews B.H., Anguiano B., Arcodia R., Armengaud E., Aubert M., Avila S., Avila-Reese V., Badenes C., Balland C., Barger K., Barrera-Ballesteros J.K., Basu S., Bautista J., Beaton R.L., Beers T.C., Benavides B.I.T., Bender C.F., Bernardi M., Bershady M., Beutler F., Bidin C.M., Bird J., Bizyaev D., Blanc G.A., Blanton M.R., Boquien M., Borissova J., Bovy J., Brandt W.N., Brinkmann J., Brownstein J.R., Bundy K., Bureau M., Burgasser A., Burtin E., Cano-Diaz M., Capasso R., Cappellari M., Carrera R., Chabanier S., Chaplin W., Chapman M., Cherinka B., Chiappini C., Doohyun Choi P., Chojnowski S.D., Chung H., Clerc N., Coffey D., Comerford J.M., Comparat J., Da Costa L., Cousinou M.-C., Covey K., Crane J.D., Cunha K., Ilha G.D.S., Dai Y.S., Damsted S.B., Darling J., Davidson J.W., Davies R., Dawson K., De N., De La Macorra A., De Lee N., Queiroz A.B.D.A., Deconto Machado A., De La Torre S., Dell'Agli F., Du Mas Des Bourboux H., Diamond-Stanic A.M., Dillon S., Donor J., Drory N., Duckworth C., Dwelly T., Ebelke G., Eftekharzadeh S., Davis Eigenbrot A., Elsworth Y.P., Eracleous M., Erfanianfar G., Escoffier S., Fan X., Farr E., Fernandez-Trincado J.G., Feuillet D., Finoguenov A., Fofie P., Fraser-Mckelvie A., Frinchaboy P.M., Fromenteau S., Fu H., Galbany L., Garcia R.A., Garcia-Hernandez D.A., Oehmichen L.A.G., Ge J., Maia M.A.G., Geisler D., Gelfand J., Goddy J., Gonzalez-Perez V., Grabowski K., Green P., Grier C.J., Guo H., Guy J., Harding P., Hasselquist S., Hawken A.J., Hayes C.R., Hearty F., Hekker S., Hogg D.W., Holtzman J.A., Horta D., Hou J., Hsieh B.-C., Huber D., Hunt J.A.S., Chitham J.I., Imig J., Jaber M., Angel C.E.J., Johnson J.A., Jones A.M., Jonsson H., Jullo E., Kim Y., Kinemuchi K., Kirkpatrick Iv C.C., Kite G.W., Klaene M., Kneib J.-P., Kollmeier J.A., Kong H., Kounkel M., Krishnarao D., Lacerna I., Lan T.-W., Lane R.R., Law D.R., Le Goff J.-M., Leung H.W., Lewis H., Li C., Lian J., Lin L., Long D., Longa-Peña P., Lundgren B., Lyke B.W., Ted Mackereth J., Macleod C.L., Majewski S.R., Manchado A., Maraston C., Martini P., Masseron T., Masters K.L., Mathur S., McDermid R.M., Merloni A., Merrifield M., Meszaros S., Miglio A., Minniti D., Minsley R., Miyaji T., Mohammad F.G., Mosser B., Mueller E.-M., Muna D., Muñoz-Gutierrez A., Myers A.D., Nadathur S., Nair P., Nandra K., Do Nascimento J.C., Nevin R.J., Newman J.A., Nidever D.L., Nitschelm C., Noterdaeme P., O'Connell J.E., Olmstead M.D., Oravetz D., Oravetz A., Osorio Y., Pace Z.J., Padilla N., Palanque-Delabrouille N., Palicio P.A., Pan H.-A., Pan K., Parker J., Paviot R., Peirani S., Ramrez K.P., Penny S., Percival W.J., Perez-Fournon I., Perez-Rafols I., Petitjean P., Pieri M.M., Pinsonneault M., Poovelil V.J., Povick J.T., Prakash A., Price-Whelan A.M., Raddick M.J., Raichoor A., Ray A., Rembold S.B., Rezaie M., Riffel R.A., Riffel R., Rix H.-W., Robin A.C., Roman-Lopes A., Roman-Zuñiga C., Rose B., Ross A.J., Rossi G., Rowlands K., Rubin K.H.R., Salvato M., Sanchez A.G., Sanchez-Menguiano L., Sanchez-Gallego J.R., Sayres C., Schaefer A., Schiavon R.P., Schimoia J.S., Schlafly E., Schlegel D., Schneider D.P., Schultheis M., Schwope A., Seo H.-J., Serenelli A., Shafieloo A., Shamsi S.J., Shao Z., Shen S., Shetrone M., Shirley R., Aguirre V.S., Simon J.D., Skrutskie M.F., Slosar A., Smethurst R., Sobeck J., Sodi B.C., Souto D., Stark D.V., Stassun K.G., Steinmetz M., Stello D., Stermer J., Storchi-Bergmann T., Streblyanska A., Stringfellow G.S., Stutz A., Suarez G., Sun J., Taghizadeh-Popp M., Talbot M.S., Tayar J., Thakar A.R., Theriault R., Thomas D., Thomas Z.C., Tinker J., Tojeiro R., Toledo H.H., Tremonti C.A., Troup N.W., Tuttle S., Unda-Sanzana E., Valentini M., Vargas-Gonzalez J., Vargas-Magaña M., Vazquez-Mata J.A., Vivek M., Wake D., Wang Y., Weaver B.A., Weijmans A.-M., Wild V., Wilson J.C., Wilson R.F., Wolthuis N., Wood-Vasey W.M., Yan R., Yang M., Yeche C., Zamora O., Zarrouk P., Zasowski G., Zhang K., Zhao C., Zhao G., Zheng Z., Zhu G., Zou H., Alfred P. Sloan Foundation, and Department of Energy (US)

Subjects
Optical telescopes, SAMPLE, Astrophysics, 01 natural sciences, Astronomi, astrofysik och kosmologi, Infrared astronomy, Observatory, Astronomy, Astrophysics and Cosmology, Astrophysics::Solar and Stellar Astrophysics, REDSHIFT 0.8, redshift surveys, stellar spectral lines, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, media_common, Astronomy databases, Redshift surveys, Physics, Astrophysics::Instrumentation and Methods for Astrophysics, stellar properties, CATALOG, astro-ph.CO, astronomy databases, Data release, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], infrared astonomy, TELESCOPE, astro-ph.GA, media_common.quotation_subject, Astrophysics::Cosmology and Extragalactic Astrophysics, MASS, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Galactic abundances, Stellar properties, 0103 physical sciences, Astrophysics::Galaxy Astrophysics, DISTANCES, Stellar spectral lines, 010308 nuclear & particles physics, Astronomy and Astrophysics, optical telescopes, 115 Astronomy, Space science, Galaxy, GALAXY, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], STELLAR, 13. Climate action, Space and Planetary Science, Sky, [SDU]Sciences of the Universe [physics], galactic abundances, MILKY, astro-ph.IM, SDSS-IV MANGA
Abstract

This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17)., Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS website is www.sdss.org.

Published
2020

32. The Aarhus red giants challenge: I. Stellar structures in the red giant branch phase

Author

Maurizio Salaris, V. Silva Aguirre, Santi Cassisi, Anwesh Mazumdar, Dennis Stello, George C. Angelou, Andrea Miglio, R. M. Ouazzani, Federico Spada, Earl P. Bellinger, Diego Bossini, Tiara Battich, M. M. Miller Bertolami, Jakob Rørsted Mosumgaard, Richard H. D. Townsend, K. B. Nielsen, Adriano Pietrinferni, Chen Jiang, S. Deheuvels, Saskia Hekker, A. Weiss, Jørgen Christensen-Dalsgaard, Aldo Serenelli, T. Constantino, Patrick Eggenberger, Yveline Lebreton, Kavli Institute for Theoretical Physics [Santa Barbara] (KITP), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Stellar Astrophysics Centre [Aarhus] (SAC), Aarhus University [Aarhus], Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), School of Physics [UNSW Sydney] (UNSW), University of New South Wales [Sydney] (UNSW), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare [Pisa] (INFN), Istituto Nazionale di Fisica Nucleare (INFN), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Collurania Astronomical Observatory, Istituto Nazionale di Astrofisica (INAF), University of Wisconsin-Madison, INAF - Osservatorio Astronomico di Padova (OAPD), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), School of Physics and Astronomy, University of Birmingham [Birmingham], Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Astrophysical Research Institute [Liverpool], Liverpool John Moore University (ljmu), Danish National Research Foundation, European Commission, Villum Fonden, Independent Research Fund Denmark, Ministerio de Ciencia e Innovación (España), Generalitat de Catalunya, Australian Research Council, National Science Foundation (US), Fundação para a Ciência e a Tecnologia (Portugal), Department of Atomic Energy (India), University of California [Santa Barbara] (UCSB), University of California-University of California, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université de Genève (UNIGE), Department of Physics and Astronomy [Aarhus], Sydney Institute for Astronomy (SIfA), The University of Sydney, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, DNK, Silva Aguirre V., Christensen-Dalsgaard J., Cassisi S., Miller Bertolami M., Serenelli A., Stello D., Weiss A., Angelou G., Jiang C., Lebreton Y., Spada F., Bellinger E.P., Deheuvels S., Ouazzani R.M., Pietrinferni A., Mosumgaard J.R., Townsend R.H.D., Battich T., Bossini D., Constantino T., Eggenberger P., Hekker S., Mazumdar A., Miglio A., Nielsen K.B., and Salaris M.

Subjects
Stellar mass, FOS: Physical sciences, evolution [Stars], Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, Asteroseismology, Luminosity, purl.org/becyt/ford/1 [https], 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Stellar structure, 010303 astronomy & astrophysics, Stellar evolution, Solar and Stellar Astrophysics (astro-ph.SR), QC, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, QB, Physics, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], interiors [Stars], Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Red-giant branch, Stars, Stars: evolution, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Stars: interiors, Astrophysics::Earth and Planetary Astrophysics
Abstract

[Context] With the advent of space-based asteroseismology, determining accurate properties of red-giant stars using their observed oscillations has become the focus of many investigations due to their implications in a variety of fields in astrophysics. Stellar models are fundamental in predicting quantities such as stellar age, and their reliability critically depends on the numerical implementation of the physics at play in this evolutionary phase., [Aims] We introduce the Aarhus red giants challenge, a series of detailed comparisons between widely used stellar evolution and oscillation codes that aim to establish the minimum level of uncertainties in properties of red giants arising solely from numerical implementations. We present the first set of results focusing on stellar evolution tracks and structures in the red-giant-branch (RGB) phase., [Methods] Using nine state-of-the-art stellar evolution codes, we defined a set of input physics and physical constants for our calculations and calibrated the convective efficiency to a specific point on the main sequence. We produced evolutionary tracks and stellar structure models at a fixed radius along the red-giant branch for masses of 1.0 M⊙, 1.5 M⊙, 2.0 M⊙, and 2.5 M⊙, and compared the predicted stellar properties., [Results] Once models have been calibrated on the main sequence, we find a residual spread in the predicted effective temperatures across all codes of ∼20 K at solar radius and ∼30–40 K in the RGB regardless of the considered stellar mass. The predicted ages show variations of 2–5% (increasing with stellar mass), which we attribute to differences in the numerical implementation of energy generation. The luminosity of the RGB-bump shows a spread of about 10% for the considered codes, which translates into magnitude differences of ∼0.1 mag in the optical V-band. We also compare the predicted [C/N] abundance ratio and find a spread of 0.1 dex or more for all considered masses., [Conclusions] Our comparisons show that differences at the level of a few percent still remain in evolutionary calculations of red giants branch stars despite the use of the same input physics. These are mostly due to differences in the energy generation routines and interpolation across opacities, and they call for further investigation on these matters in the context of using properties of red giants as benchmarks for astrophysical studies., Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement No. DNRF106). The research was supported by the ASTERISK project (ASTERoseismic Investigations with SONG and Kepler) funded by the European Research Council (Grant agreement No. 267864). VSA acknowledges support from VILLUM FONDEN (research grant 10118) and the Independent Research Fund Denmark (Research grant 7027-00096B). AS is partially supported by grant ESP2017-82674-R (MICINN) and 2017-SGR-1131 (Generalitat Catalunya). DS acknowledges support from the Australian Research Council. Part of this research was supported by the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no 338251 (StellarAges). RHDT acknowledges support from National Science Foundation grants ACI-1663696 and AST-1716436. This work was supported by FCT/MCTES through national funds and by FEDER – Fundo Europeu de Desenvolvimento Regional through COMPETE2020 – Programa Operacional Competitividade e Internacionalização by these grants: UID/FIS/04434/2019; PTDC/FIS-AST/30389/2017 and POCI-01-0145-FEDER-030389. DB is supported in the form of work contract funded by national funds through Fundação para a Ciência e Tecnologia (FCT). AM acknowledges the support of the Govt. Of India, Department of Atomic Energy, under Project No. 12-R&D-TFR-6.04-0600. We would like to thank Bill Paxton for assistance with the MESA solar calibration and for accommodating requested changes to the code along the way.

Published
2020

33. Age dating of an early Milky Way merger via asteroseismology of the naked-eye star ν Indi

Author

William J. Chaplin, Aldo M. Serenelli, Andrea Miglio, Thierry Morel, J. Ted Mackereth, Fiorenzo Vincenzo, Hans Kjeldsen, Sarbani Basu, Warrick H. Ball, Amalie Stokholm, Kuldeep Verma, Jakob Rørsted Mosumgaard, Victor Silva Aguirre, Anwesh Mazumdar, Pritesh Ranadive, H. M. Antia, Yveline Lebreton, Joel Ong, Thierry Appourchaux, Timothy R. Bedding, Jørgen Christensen-Dalsgaard, Orlagh Creevey, Rafael A. García, Rasmus Handberg, Daniel Huber, Steven D. Kawaler, Mikkel N. Lund, Travis S. Metcalfe, Keivan G. Stassun, Michäel Bazot, Paul G. Beck, Keaton J. Bell, Maria Bergemann, Derek L. Buzasi, Othman Benomar, Diego Bossini, Lisa Bugnet, Tiago L. Campante, Zeynep Çelik Orhan, Enrico Corsaro, Lucía González-Cuesta, Guy R. Davies, Maria Pia Di Mauro, Ricky Egeland, Yvonne P. Elsworth, Patrick Gaulme, Hamed Ghasemi, Zhao Guo, Oliver J. Hall, Amir Hasanzadeh, Saskia Hekker, Rachel Howe, Jon M. Jenkins, Antonio Jiménez, René Kiefer, James S. Kuszlewicz, Thomas Kallinger, David W. Latham, Mia S. Lundkvist, Savita Mathur, Josefina Montalbán, Benoit Mosser, Andres Moya Bedón, Martin Bo Nielsen, Sibel Örtel, Ben M. Rendle, George R. Ricker, Thaíse S. Rodrigues, Ian W. Roxburgh, Hossein Safari, Mathew Schofield, Sara Seager, Barry Smalley, Dennis Stello, Róbert Szabó, Jamie Tayar, Nathalie Themeßl, Alexandra E. L. Thomas, Roland K. Vanderspek, Walter E. van Rossem, Mathieu Vrard, Achim Weiss, Timothy R. White, Joshua N. Winn, Mutlu Yıldız, European Commission, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Generalitat de Catalunya, Chaplin W.J., Serenelli A.M., Miglio A., Morel T., Mackereth J.T., Vincenzo F., Kjeldsen H., Basu S., Ball W.H., Stokholm A., Verma K., Mosumgaard J.R., Silva Aguirre V., Mazumdar A., Ranadive P., Antia H.M., Lebreton Y., Ong J., Appourchaux T., Bedding T.R., Christensen-Dalsgaard J., Creevey O., Garcia R.A., Handberg R., Huber D., Kawaler S.D., Lund M.N., Metcalfe T.S., Stassun K.G., Bazot M., Beck P.G., Bell K.J., Bergemann M., Buzasi D.L., Benomar O., Bossini D., Bugnet L., Campante T.L., Orhan Z.C., Corsaro E., Gonzalez-Cuesta L., Davies G.R., Di Mauro M.P., Egeland R., Elsworth Y.P., Gaulme P., Ghasemi H., Guo Z., Hall O.J., Hasanzadeh A., Hekker S., Howe R., Jenkins J.M., Jimenez A., Kiefer R., Kuszlewicz J.S., Kallinger T., Latham D.W., Lundkvist M.S., Mathur S., Montalban J., Mosser B., Bedon A.M., Nielsen M.B., Ortel S., Rendle B.M., Ricker G.R., Rodrigues T.S., Roxburgh I.W., Safari H., Schofield M., Seager S., Smalley B., Stello D., Szabo R., Tayar J., Themessl N., Thomas A.E.L., Vanderspek R.K., van Rossem W.E., Vrard M., Weiss A., White T.R., Winn J.N., Yildiz M., Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Psychology, St John's University, Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), School of Physics and Astronomy, University of Birmingham [Birmingham], Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), Danish AsteroSeismology Centre (DASC), Aarhus University [Aarhus], Department of Astronomy, Yale University [New Haven], Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Sydney Institute for Astronomy (SIfA), The University of Sydney, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Research institute of Computer Vision and Robotics [Girona] (VICOROB), Universitat de Girona (UdG), Department of Physics and Astronomy [Aarhus], Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), NASA Ames Research Center (ARC), Centre for Automation and Robotics (CAR), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad Politécnica de Madrid (UPM), Kiepenheuer-Institut für Sonnenphysik (KIS), Stellar Astrophysics Centre [Aarhus] (SAC), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), High Altitude Observatory (HAO), National Center for Atmospheric Research [Boulder] (NCAR), Département des Sciences et Gestion de l'Environnement/Océanologie [Liège], Université de Liège, Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), High Speed Networks Laboratory, Dept. of Telecommunications and Media Informatics, Budapest University of Technology and Economics [Budapest] (BME), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Observatoire de Paris, Université Paris sciences et lettres (PSL), Ege Üniversitesi, CERFACS [Toulouse], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universidad Politécnica de Madrid (UPM)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), PSL Research University (PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Milky Way, Population, GAIA, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, MASS, CHEMICAL-COMPOSITION, Q1, 01 natural sciences, Asteroseismology, 0103 physical sciences, QB460, Satellite galaxy, STELLAR HALOES, Astrophysics::Solar and Stellar Astrophysics, 10. No inequality, education, 010303 astronomy & astrophysics, QB600, QC, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Dwarf galaxy, QB, Physics, [PHYS]Physics [physics], education.field_of_study, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], ACCRETION HISTORY, Astronomy and Astrophysics, DISC, Astrophysics - Astrophysics of Galaxies, Galaxy, MODEL, Stars, Astrophysics - Solar and Stellar Astrophysics, DARK-MATTER HALOES, ROTATION, Halo, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], SOLAR-LIKE OSCILLATIONS, QB799
Abstract

This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). et al., Over the course of its history, the Milky Way has ingested multiple smaller satellite galaxies. Although these accreted stellar populations can be forensically identified as kinematically distinct structures within the Galaxy, it is difficult in general to date precisely the age at which any one merger occurred. Recent results have revealed a population of stars that were accreted via the collision of a dwarf galaxy, called Gaia–Enceladus, leading to substantial pollution of the chemical and dynamical properties of the Milky Way. Here we identify the very bright, naked-eye star ν Indi as an indicator of the age of the early in situ population of the Galaxy. We combine asteroseismic, spectroscopic, astrometric and kinematic observations to show that this metal-poor, alpha-element-rich star was an indigenous member of the halo, and we measure its age to be 11.0±0.7 (stat) ±0.8 (sys) billion years. The star bears hallmarks consistent with having been kinematically heated by the Gaia–Enceladus collision. Its age implies that the earliest the merger could have begun was 11.6 and 13.2 billion years ago, at 68% and 95% confidence, respectively. Computations based on hierarchical cosmological models slightly reduce the above limits., J.M. acknowledge support from the ERC Consolidator Grant funding scheme (project ASTEROCHRONOMETRY, grant agreement number 772293). A.M.S. is partially supported by the Spanish Government (ESP2017-82674-R) and Generalitat de Catalunya (2017-SGR-1131). T.L.C. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement number 792848 (PULSATION). K.J.B., S.H., J.S.K. and N.T. are supported by the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement number 338251 (StellarAges). E.C. is funded by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement number 664931. L.G.-C. acknowledges support from the MINECO FPI-SO doctoral research project SEV-2015-0548-17-2 and predoctoral contract BES-2017-082610. S.M. acknowledges support from the Spanish ministry through the Ramon y Cajal fellowship number RYC-2015-17697. This work was supported by FEDER through COMPETE2020 (POCI-01-0145-FEDER-030389. A.M.B. acknowledges funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 749962 (project THOT).

Published
2020

34. Solar cycle variation of νmax in helioseismic data and its implications for asteroseismology

Author

Steven J. Hale, Yvonne Elsworth, Martin Bo Nielsen, William J. Chaplin, Warrick H. Ball, Lucas S. Viani, Andrea Miglio, Guy R. Davies, Sarbani Basu, Rachel Howe, Howe R., Chaplin W.J., Basu S., Ball W.H., Davies G.R., Elsworth Y., Hale S.J., Miglio A., Nielsen M.B., and Viani L.S.

Subjects
010504 meteorology & atmospheric sciences, asteroseismology, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Asteroseismology, Spectral line, Photometry (optics), Sun: activity, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, High activity, activity [Sun], helioseismology [Sun], 010303 astronomy & astrophysics, Scaling, Sun: helioseismology, 0105 earth and related environmental sciences, Physics, Astronomy and Astrophysics, Doppler velocity, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Physics::Space Physics, Significant positive correlation, Astrophysics::Earth and Planetary Astrophysics
Abstract

The frequency, $\nu_{\rm max}$, at which the envelope of pulsation power peaks for solar-like oscillators is an important quantity in asteroseismology. We measure $\nu_{\rm max}$ for the Sun using 25 years of Sun-as-a-Star Doppler velocity observations with the Birmingham Solar-Oscillations Network (BiSON), by fitting a simple model to binned power spectra of the data. We also apply the fit to Sun-as-a-Star Doppler velocity data from GONG and GOLF, and photometry data from VIRGO/SPM on the ESA/NASA SOHO spacecraft. We discover a weak but nevertheless significant positive correlation of the solar $\nu_{\rm max}$ with solar activity. The uncovered shift between low and high activity, of $\simeq 25\,\rm \mu Hz$, translates to an uncertainty of 0.8 per cent in radius and 2.4 per cent in mass, based on direct use of asteroseismic scaling relations calibrated to the Sun. The mean $\nu_{\rm max}$ in the different datasets is also clearly offset in frequency. Our results flag the need for caution when using $\nu_{\rm max}$ in asteroseismology., Comment: 6 pages, 4 figures, published in MNRAS Letters, 2020, vol 493, pages L49 - 53 Corrected error in metadata list of authors

Published
2020
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35. TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star

Author

Andrés Jordán, Derek Buzasi, K. I. Collins, Joshua Pepper, Jon M. Jenkins, Alexander Lyttle, Martin Schlecker, Ismael Mireles, Sara Seager, Brett C. Addison, Andrea Miglio, Jack Okumura, Savita Mathur, Christopher Tylor, Daniel R. Hey, Victor Silva Aguirre, Zhao Guo, Tansu Daylan, Paula Sarkis, Mikkel N. Lund, J. S. Bentley, Martin Bo Nielsen, Joshua E. Schlieder, Keivan G. Stassun, Aldo Serenelli, Jonathan Horner, Stephen R. Kane, Tiago L. Campante, B. D. Carter, Joshua N. Winn, Hui Zhang, Diana Kossakowski, Thomas Henning, Brendan P. Bowler, Rasmus Handberg, Jake T. Clark, Warrick H. Ball, Matthew W. Mengel, Pamela Rowden, L. González-Cuesta, Karen A. Collins, Andrew W. Mann, Nicholas M. Law, John F. Kielkopf, B. Mosser, Daniel Huber, Ian J. M. Crossfield, Mathieu Clerte, Michaela Collins, Ashley Chontos, Songhu Wang, Belinda A. Nicholson, Pascal Torres, Thomas Kallinger, Robert A. Wittenmyer, Stephen C. Marsden, Andrew Vanderburg, Dag Evensberget, N. Themeßl, Rachel A. Matson, José Dias do Nascimento, David W. Latham, Cenk Kayhan, Timothy R. Bedding, Allen B. Davis, Emilie Laychock, J. O'Connor, Néstor Espinoza, B. Cale, Andrius Burnelis, S. Hekker, Steven D. Kawaler, Avi Shporer, Duncan J. Wright, Sarbani Basu, Peter Plavchan, James S. Kuszlewicz, Guy R. Davies, Teo Mocnik, Leandro de Almeida, Jason D. Eastman, Carl Ziegler, Rafael Brahm, Enrico Corsaro, William J. Chaplin, C. G. Tinney, Catherine Stevens, Rafael A. García, Sergi Blanco-Cuaresma, Steve B. Howell, Alexis Heitzmann, Roland Vanderspek, Thiam-Guan Tan, George R. Ricker, Addison, Brett C, Wright, Duncan J, Nicholson, Belinda A, Cale, Bryson, Mocnik, Teo, Huber, Daniel, Plavchan, Peter, Wittenmyer, Robert A, Vanderburg, Andrew, Chaplin, William J, Chontos, Ashley, Clark, Jake T, Eastman, Jason D, Ziegler, Carl, Brahm, Rafael, Carter, Bradley D, Clerte, Mathieu, Espinoza, Néstor, Horner, Jonathan, Bentley, John, Jordán, André, Kane, Stephen R, Kielkopf, John F, Laychock, Emilie, Mengel, Matthew W, Okumura, Jack, Stassun, Keivan G, Bedding, Timothy R, Bowler, Brendan P, Burnelis, Andriu, Blanco-Cuaresma, Sergi, Collins, Michaela, Crossfield, Ian, Davis, Allen B, Evensberget, Dag, Heitzmann, Alexi, Howell, Steve B, Law, Nichola, Mann, Andrew W, Marsden, Stephen C, Matson, Rachel A, O’Connor, James H, Shporer, Avi, Stevens, Catherine, Tinney, C G, Tylor, Christopher, Wang, Songhu, Zhang, Hui, Henning, Thoma, Kossakowski, Diana, Ricker, George, Sarkis, Paula, Schlecker, Martin, Torres, Pascal, Vanderspek, Roland, Latham, David W, Seager, Sara, Winn, Joshua N, Jenkins, Jon M, Mireles, Ismael, Rowden, Pam, Pepper, Joshua, Daylan, Tansu, Schlieder, Joshua E, Collins, Karen A, Collins, Kevin I, Tan, Thiam-Guan, Ball, Warrick H, Basu, Sarbani, Buzasi, Derek L, Campante, Tiago L, Corsaro, Enrico, González-Cuesta, L, Davies, Guy R, de Almeida, Leandro, do Nascimento, Jose-Dia, García, Rafael A, Guo, Zhao, Handberg, Rasmu, Hekker, Saskia, Hey, Daniel R, Kallinger, Thoma, Kawaler, Steven D, Kayhan, Cenk, S. Kuszlewicz, Jame, Lund, Mikkel N, Lyttle, Alexander, Mathur, Savita, Miglio, Andrea, Mosser, Benoit, Nielsen, Martin B, Serenelli, Aldo M, Aguirre, Victor Silva, Themeßl, Nathalie, National Aeronautics and Space Administration (US), National Science Foundation (US), Danish National Research Foundation, National Natural Science Foundation of China, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, European Commission, Centre National D'Etudes Spatiales (France), Ministerio de Economía y Competitividad (España), Kavli Institute for Theoretical Physics, Independent Research Fund Denmark, Carlsberg Foundation, Addison, Brett C., Wright, Duncan J., Nicholson, Belinda A., Wittenmyer, Robert A., Chaplin, William J., Clark, Jake T., Eastman, Jason D., Carter, Bradley D., Kane, Stephen R., Kielkopf, John F., Mengel, Matthew W., Stassun, Keivan G., Bedding, Timothy R., Bowler, Brendan P., Davis, Allen B., Howell, Steve B., Mann, Andrew W., Marsden, Stephen C., Matson, Rachel A., O'Connor, Jame, Tinney, C. G., Latham, David W., Winn, Joshua N., Jenkins, Jon M., Schlieder, Joshua E., Collins, Karen A., Collins, Kevin I., Ball, Warrick H., Buzasi, Derek L., Campante, Tiago L., González-Cuesta, Lucía, Davies, Guy R., do Nascimento, Jose-Dias, Jr., García, Rafael A., Hey, Daniel R., Kawaler, Steven D., Kuszlewicz, James S., Lund, Mikkel N., Nielsen, Martin B., Serenelli, Aldo M., and Silva Aguirre, Victor

Subjects
astro-ph.SR, Star (game theory), FOS: Physical sciences, Context (language use), Astrophysics, asteroseismology, Type (model theory), 01 natural sciences, Asteroseismology, spectroscopic [Techniques], techniques: photometric, stars: individual (TIC 200723869/TOI-257), 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Earth and Planetary Astrophysics (astro-ph.EP), individual (TIC 200723869/TOI-257) [Stars], radial velocities [Techniques], 010308 nuclear & particles physics, photometric [Techniques], techniques: radial velocitie, Astronomy and Astrophysics, Planetary system, planetary system, Exoplanet, Radial velocity, Stars, Planetary systems, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Techniques: radial velocities, astro-ph.EP, techniques: spectroscopic, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of MP = 0.138 ± 0.023 M J (43.9 ± 7.3, M⊕), a radius of RP = 0.639 ± 0.013 R J (7.16 ± 0.15, R ⊕), bulk density of 0.65+0.12-0.11 (cgs), and period 18.38818 +0.00085 -0.00084 days. TOI-257b orbits a bright (V = 7.612 mag) somewhat evolved late F-type star with M∗ = 1.390 ± 0.046 rm M sun, R∗ = 1.888 ± 0.033 Rsun, Teff = 6075 ± 90 rm K, and vsin i = 11.3 ± 0.5 km s-1. Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a ∼71 day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars (∼100) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems., Daniel Huber acknowledges support by the National Aeronautics and Space Administration through the TESS Guest Investigator Program (80NSSC18K1585) and by the National Science Foundation (AST-1717000). Ashley Chontos acknowledges support from the National Science Foundation through the Graduate Research Fellowship Program (DGE 1842402). William J. Chaplin, Warrick H. Ball, Martin B. Nielsen, and Andrea Miglio. acknowledge support from the Science and Technology Facilities Council and UK Space Agency. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant DNRF106). Rafael Brahm acknowledges support from National Fund for Scientific and Technological Development Post-doctoral Fellowship Project 3180246, and from the Millennium Institute of Astrophysics (MAS). H.Z. Hui Zhang is supported by the Natural Science Foundation of China (NSFC grants 11673011, 11933001). Andres Jordan acknowledges support from FONDECYT project 1171208 and by the Ministry for the Economy, Development, and Tourism’s Programa Iniciativa Científica Milenio through grant IC 120009, awarded to the Millennium Institute of Astrophysics (MAS). Aldo M. Serenelli is partially supported by grants ESP2017-82674-R (Spanish Government) and 2017-SGR-1131 (Generalitat de Catalunya). Andrea Miglio acknowledges support from the European Research Council Consolidator Grant funding scheme (project ASTEROCHRONOMETRY, G.A. number 772293). Rafael A. Garcia acknowledges the support of the PLAnetary Transits and Oscillations of stars grant from the Centre National d'Études Spatiales. Savita Mathur acknowledges support from the Spanish Ministry with the Ramon y Cajal fellowship number RYC-2015-17697. Tiago L. Campante acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 792848 (PULSATION). This work was supported by Foundation of Science and Technology/Ministry of Science, Technology and Higher Education through national funds (UID/FIS/04434/2019). Enrico Corsaro is funded by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 664931. L. González-Cuesta thanks the support from grant FPI-SO from the Spanish Ministry of Economy and Competitiveness (MINECO) (research project SEV-2015-0548-17-2 and predoctoral contract BES-2017-082610). Sarbani Basu acknowledges NASA grant NNX16AI09G and NSF grant AST-1514676. Ian J. M. Crossfield acknowledges support from the NSF through grant AST-1824644, and from NASA through Caltech/JPL grant RSA-1610091. Tansu Daylan acknowledges support from MIT’s Kavli Institute as a Kavli postdoctoral fellow. Derek L. Buzasi acknowledges support from NASA through the TESS Guest Investigator program (80NSSC19K0385). Cenk Kayhan acknowledges support by Erciyes University Scientific Research Projects Coordination Unit under grant number MAP-2020-9749. Emilie Laychock and Michaela Collins acknowledge support by the National Science Foundation under grant 1559487. Victor Silva Aguirre acknowledges support from the Independent Research Fund Denmark (Research grant 7027-00096B) and the Carlsberg Foundation (grant agreement CF19-0649).

Published
2020
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36. Properties of the Hyades, the eclipsing binary HD27130, and the oscillating red giant epsilon Tauri

Author

Gražina Tautvaišienė, Šarūnas Mikolaitis, Don A. VandenBerg, Gilles Otten, H. Kjeldsen, Andrea Miglio, Torben Arentoft, R. Minkevičiūtė, Jens Jessen-Hansen, Rimvydas Janulis, Karsten Brogaard, Pere L. Palle, Arnas Drazdauskas, Timothy R. White, Patrick Dorval, D. Slumstrup, V. Bagdonas, Ignas Snellen, M. Fredslund Andersen, E. Stonkutė, Alessandro Marchini, Frank Grundahl, G. J. J. Talens, E. Pakštienė, Brogaard K., Pakstiene E., Grundahl F., Mikolaitis S., Tautvaisiene G., Slumstrup D., Talens G.J.J., Vandenberg D.A., Miglio A., Arentoft T., Kjeldsen H., Janulis R., Drazdauskas A., Marchini A., Minkeviciute R., Stonkute E., Bagdonas V., Fredslund Andersen M., Jessen-Hansen J., Palle P.L., Dorval P., Snellen I.A.G., Otten G.P.P.L., White T.R., Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
oscillations [stars], Red giant, Open clusters and associations: individual: Hyade, Binaries: eclipsing, Astrophysics, 01 natural sciences, eclipsing [binaries], Astrophysics::Solar and Stellar Astrophysics, Abundances, 010303 astronomy & astrophysics, Physics, individual: E Tau [stars], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Star cluster, Astrophysics - Solar and Stellar Astrophysics, Stars: individual: HD27130, Astrophysics::Earth and Planetary Astrophysics, open clusters and associations: individual: Hyades, NGC 6791, Hyades, Oscillations, Stars: abundance, stars: abundances, Stars: individual: ϵ Tau, Metallicity, MODELS, Open Clusters and Associations, Individual, Astrophysics::Cosmology and Extragalactic Astrophysics, 0103 physical sciences, Binary star, Stars: oscillations, individual: HD27130 [stars], SPECTRA, individual: Hyades [open clusters and associations], Eclipsing, SOLAR, Astrophysics::Galaxy Astrophysics, RADIAL-VELOCITY, stars: individual: ɛ Tau, 010308 nuclear & particles physics, Binaries, White dwarf, Astronomy and Astrophysics, Light curve, Giant star, Stars, EVOLUTION, abundances [stars], HD27130, [SDU]Sciences of the Universe [physics], Space and Planetary Science, ɛ Tau, OPEN CLUSTERS, DISTANCE, STARS, ASTEROSEISMIC MASS
Abstract

Eclipsing binary stars allow derivation of accurate and precise masses and radii. When they reside in star clusters, properties of even higher precision, along with additional information, can be extracted. Asteroseismology of solar-like oscillations offers similar possibilities for single stars. We improve the previously established properties of the Hyades eclipsing binary HD27130 and re-assess the asteroseismic properties of the giant star $\epsilon$ Tau. The physical properties of these members of the Hyades are then used to constrain the helium content and age of the cluster. New multi-colour light curves were combined with multi-epoch radial velocities to yield masses and radii of HD27130. $T_{\rm eff}$ was derived from spectroscopy and photometry, and verified using the Gaia parallax. We estimate the cluster age from re-evaluated asteroseismic properties of $\epsilon$ Tau while using HD27130 to constrain the helium content. The masses and radii, and $T_{\rm eff}$ of HD 27130 were found to be $M=1.0245\pm0.0024 M_{\odot}$, $R=0.9226\pm0.015 R_{\odot}$, $T_{\rm eff}=5650\pm50$ K for the primary, and $M=0.7426\pm0.0016 M_{\odot}$, $R=0.7388\pm0.026 R_{\odot}$, $T_{\rm eff}=4300\pm100$ K for the secondary component. Our re-evaluation of $\epsilon$ Tau suggests that the previous literature estimates are trustworthy, and that the Hipparcos parallax is more reliable than the Gaia DR2 parallax. The helium content of HD27130 and thus of the Hyades is found to be $Y=0.27$ but with significant model dependence. Correlations with the adopted metallicity results in a robust helium enrichment law with $\frac{\Delta Y}{\Delta Z}$ close to 1.2. We estimate the age of the Hyades to be 0.9 $\pm$ 0.1 (stat) $\pm$ 0.1 (sys) Gyr in slight tension with recent age estimates based on the cluster white dwarfs. (abridged), Comment: 14 pages, 8 figures, accepted for publication in Astronomy & Astrophysics

Published
2020
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37. Asteroseismology of evolved stars to constrain the internal transport of angular momentum

Author

Andrea Miglio, Patrick Eggenberger, G. Buldgen, Sébastien Salmon, Josefina Montalbán, L. Fellay, Saniya Khan, and L. Fellay, G. Buldgen, P. Eggenberger, S. Khan, S. J. A. J. Salmon, A. Miglio, J. Montalbán

Subjects
Angular momentum, Red giant, FOS: Physical sciences, Astrophysics, Rotation, 01 natural sciences, Asteroseismology, symbols.namesake, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Stars: individual: KIC 6448890, 010308 nuclear & particles physics, Computer Science::Information Retrieval, Stars: rotation, Astronomy and Astrophysics, Markov chain Monte Carlo, Stars: interior, Computational physics, Stars: evolution, Stars, Astrophysics - Solar and Stellar Astrophysics, Convection zone, 13. Climate action, Space and Planetary Science, symbols, Astrophysics::Earth and Planetary Astrophysics
Abstract

The observations of global stellar oscillations of post main-sequence stars by space-based photometry missions allowed to directly determine their internal rotation. These constraints have pointed towards the existence of angular momentum transport processes unaccounted for in theoretical models. Constraining the properties of their internal rotation thus appears as the golden path to determine the physical nature of these missing dynamical processes. We wish to determine the robustness of a new approach to study the internal rotation of post main-sequence stars, using parametric rotation profiles coupled to a global optimization technique. We test our methodology on Kepler 56, a red giant observed by the Kepler mission. First, we carry out an extensive modelling of the star using global and local minimizations techniques, and seismic inversions. Then, using our best model, we study in details its internal rotation profile, we adopted a Bayesian approach to constrain stellar parametric predetermined rotation profiles using a Monte Carlo Markov Chain analysis of the rotational splittings of mixed modes. Our Monte Carlo Markov Chain analysis of the rotational splittings allows to determine the core and envelope rotation of Kepler 56 as well as give hints about the location of the transition between the slowly rotating envelope and the fast rotating core. We are able to discard a rigid rotation profile in the radiative regions followed by a power-law in the convective zone and show that the data favours a transition located in the radiative region, as predicted by processes originating from a turbulent nature. Our analysis of Kepler 56 indicates that turbulent processes whose transport efficiency is reduced by chemical gradients are favoured, while large scale fossil magnetic fields are disfavoured as a solution to the missing angular momentum transport., accepted for publication in Astronomy and Astrophysics

Published
2021

38. Weighing in on the masses of retired A stars with asteroseismology: K2 observations of the exoplanet-host star HD 212771

Author

Tiago L. Campante, Mikkel N. Lund, Andrea Miglio, Benjamin F. Cooke, Guy R. Davies, T. S. Rodrigues, Yvonne Elsworth, William J. Chaplin, Thierry Morel, Andrew Vanderburg, Daniel Huber, Dimitri Veras, John Asher Johnson, James S. Kuszlewicz, and Thomas S. H. North

Subjects
PLANET HOSTS, Stellar mass, individual: HD 212771 [stars], FOS: Physical sciences, STELLAR ASTROPHYSICS MESA, asteroseismology, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, star interactions, 01 natural sciences, Asteroseismology, photometric [techniques], ATMOSPHERIC PARAMETERS, Planet, 0103 physical sciences, EVOLVED STARS, Astrophysics::Solar and Stellar Astrophysics, MAIN-SEQUENCE, planetary systems, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, RED-CLUMP STARS, 010308 nuclear & particles physics, Subgiant, Astronomy, Astronomy and Astrophysics, Planetary system, GIANT STARS, Exoplanet, Stars, Astrophysics - Solar and Stellar Astrophysics, FUNDAMENTAL PROPERTIES, planet, Space and Planetary Science, Stellar mass loss, spectroscopic [techniques], Astrophysics::Earth and Planetary Astrophysics, BOLOMETRIC CORRECTIONS, SOLAR-LIKE OSCILLATIONS, Astrophysics - Earth and Planetary Astrophysics
Abstract

Doppler-based planet surveys point to an increasing occurrence rate of giant planets with stellar mass. Such surveys rely on evolved stars for a sample of intermediate-mass stars (so-called retired A stars), which are more amenable to Doppler observations than their main-sequence progenitors. However, it has been hypothesised that the masses of subgiant and low-luminosity red-giant stars targeted by these surveys --- typically derived from a combination of spectroscopy and isochrone fitting --- may be systematically overestimated. Here, we test this hypothesis for the particular case of the exoplanet-host star HD 212771 using K2 asteroseismology. The benchmark asteroseismic mass ($1.45^{+0.10}_{-0.09}\:\text{M}_{\odot}$) is significantly higher than the value reported in the discovery paper ($1.15\pm0.08\:\text{M}_{\odot}$), which has been used to inform the stellar mass-planet occurrence relation. This result, therefore, does not lend support to the above hypothesis. Implications for the fates of planetary systems are sensitively dependent on stellar mass. Based on the derived asteroseismic mass, we predict the post-main-sequence evolution of the Jovian planet orbiting HD 212771 under the effects of tidal forces and stellar mass loss., Accepted for publication in MNRAS; 10 pages, 3 figures, 2 tables

Published
2017

39. TESS asteroseismology of the known red-giant host stars HD 212771 and HD 203949

Author

Filipe Pereira, S. G. Sousa, Daniel Huber, S. Stock, James S. Kuszlewicz, Marc Hon, Mário J. P. F. G. Monteiro, Stephen R. Kane, Rafael A. García, Vardan Adibekyan, Tiago L. Campante, Sabine Reffert, Dennis Stello, Zeynep Çelik Orhan, Guy R. Davies, Martin Bo Nielsen, Timothy R. Bedding, Mutlu Yildiz, Benard Nsamba, Jørgen Christensen-Dalsgaard, Elisa Delgado Mena, H. M. Antia, Sibel Örtel, Maria Tsantaki, Victor Silva Aguirre, Rasmus Handberg, Miles Lucas, Margarida S. Cunha, Sarbani Basu, Savita Mathur, Enrico Corsaro, Nicolas Nardetto, William J. Chaplin, Warrick H. Ball, Mathieu Vrard, Hans Kjeldsen, Jacob L. Bean, Travis S. Metcalfe, Benoit Mosser, Keivan G. Stassun, Aldo Serenelli, Steven D. Kawaler, Margaret C. Turnbull, Mikkel N. Lund, Marc H. Pinsonneault, Dimitri Veras, Andrea Miglio, Diego Bossini, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), Department of Astronomy, Yale University [New Haven], Sydney Institute for Astronomy (SIfA), The University of Sydney, Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Stellar Astrophysics Centre [Aarhus] (SAC), High Altitude Observatory (HAO), National Center for Atmospheric Research [Boulder] (NCAR), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Landessternwarte Königstuhl [ZAH] (LSW), Universität Heidelberg [Heidelberg], Observatoire de Paris, Université Paris sciences et lettres (PSL), Department of Psychology, St John's University, Danish AsteroSeismology Centre (DASC), School of Physics and Astronomy, University of Birmingham [Birmingham], Instituto de Patologia e Imunologia Molecular, Universidade do Porto, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universität Heidelberg [Heidelberg] = Heidelberg University, Universidade do Porto = University of Porto, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL), Universidade do Porto [Porto], and Ege Üniversitesi

Subjects
010504 meteorology & atmospheric sciences, Red giant, Star (game theory), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Asteroseismology, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Transit (astronomy), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Exoplanets, Astronomy and Astrophysics, Exoplanet, Stars, Evolved stars, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract

Orhan, Zeynep Celik/0000-0002-9424-2339; Serenelli, Aldo/0000-0001-6359-2769; Monteiro, Mario J. P. F. G./0000-0003-0513-8116; Huber, Daniel/0000-0001-8832-4488; Adibekyan, Vardan/0000-0002-0601-6199; Reffert, Sabine/0000-0002-0460-8289; Stock, Stephan/0000-0002-1166-9338; Stassun, Keivan/0000-0002-3481-9052; Cunha, Margarida/0000-0001-8237-7343; Kuszlewicz, James/0000-0002-3322-5279; Lund, Mikkel Norup/0000-0001-9214-5642; Mathur, Savita/0000-0002-0129-0316; Nielsen, Martin Bo/0000-0001-9169-2599; Mosser, Benoit/0000-0002-7547-1208; Pereira, Filipe/0000-0002-2157-7146; Lucas, Miles/0000-0001-6341-310X; miglio, andrea/0000-0001-5998-8533; Ball, Warrick/0000-0002-4773-1017; Basu, Sarbani/0000-0002-6163-3472; Veras, Dimitri/0000-0001-8014-6162; Handberg, Rasmus/0000-0001-8725-4502; Christensen-Dalsgaard, Jorgen/0000-0001-5137-0966; Delgado Mena, Elisa/0000-0003-4434-2195, WOS: 000498546800001, The Transiting Exoplanet Survey Satellite (TESS) is performing a near all-sky survey for planets that transit bright stars. in addition, its excellent photometric precision enables asteroseismology of solar-type and red-giant stars, which exhibit convection-driven, solar-like oscillations. Simulations predict that TESS will detect solar-like oscillations in nearly 100 stars already known to host planets. in this paper, we present an asteroseismic analysis of the known red-giant host stars HD;212771 and HD;203949, both systems having a long-period planet detected through radial velocities. These are the first detections of oscillations in previously known exoplanet-host stars by TESS, further showcasing the mission?s potential to conduct asteroseismology of red-giant stars. We estimate the fundamental properties of both stars through a grid-based modeling approach that uses global asteroseismic parameters as input. We discuss the evolutionary state of HD;203949 in depth and note the large discrepancy between its asteroseismic mass (M-* = 1.23 0.15 MM* = 1.00 0.16 M if in the clump) and the mass quoted in the discovery paper (M-* = 2.1 0.1 M), implying a change >30% in the planet?s mass. Assuming HD;203949 to be in the clump, we investigate the planet?s past orbital evolution and discuss how it could have avoided engulfment at the tip of the red-giant branch. Finally, HD;212771 was observed by K2 during its Campaign 3, thus allowing for a preliminary comparison of the asteroseismic performances of TESS and K2. We estimate the ratio of the observed oscillation amplitudes for this star to be, NASA Explorer ProgramNational Aeronautics & Space Administration (NASA); ESA PRODEXEuropean Space Agency [PEA 4000119301]; Stellar Astrophysics Centre (SAC) - Danish National Research Foundation [DNRF106]; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grantEuropean Union (EU) [792848, 664931]; FCT/MCTESPortuguese Foundation for Science and Technology [UID/FIS/04434/2019]; FCTPortuguese Foundation for Science and Technology [PTDC/FIS-AST/30389/2017, PTDC/FIS-AST/28953/2017, PTDC/FIS-AST/32113/2017, CEECIND/02619/2017, IF/00650/2015/CP1273/CT0001, IF/00028/2014/CP1215/CT0002]; FEDER through COMPETE2020 [POCI-01-0145-FEDER-030389, POCI-01-0145-FEDER-028953, POCI-01-0145-FEDER-032113]; National Science Foundation under the Kavli Institute for Theoretical Physics program "Better Stars, Better Planets" [NSF PHY-1748958]; European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant [338251]; ESA PRODEX programme; CNES through the PLATO grants; Spanish GovernmentSpanish Government [ESP2017-82674-R]; Generalitat de CatalunyaGeneralitat de Catalunya [2017-SGR-1131]; STFC via an Ernest Rutherford Fellowship [ST/P003850/1]; NSFNational Science Foundation (NSF) [AST-1514676]; NASANational Aeronautics & Space Administration (NASA) [NNX16AI09G]; Spanish Ministry through the Ramon y Cajal fellowship [RYC-2015-17697]; NYUAD Institute [G1502]; DFGGerman Research Foundation (DFG) [SPP 1992, RE 2694/5-1]; Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TUBITAK:118F352]; National Aeronautics and Space Administration through the TESS Guest Investigator Program [80NSSC18K1585, 80NSSC19K0379]; European Social Fund via the Lithuanian Science Council [09.3.3-LMT-K-712-01-0103], This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program. Funding for the TESS Asteroseismic Science Operations Center at Aarhus University is provided by ESA PRODEX (PEA 4000119301) and Stellar Astrophysics Centre (SAC), funded by the Danish National Research Foundation (Grant agreement No.: DNRF106). the project leading to this publication has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No..792848 (PULSATION). This work was supported by FCT/MCTES through national funds (UID/FIS/04434/2019). This work was supported by FCT through national funds (PTDC/FIS-AST/30389/2017, PTDC/FIS-AST/28953/2017, and PTDC/FIS-AST/32113/2017) and by FEDER through COMPETE2020 (POCI-01-0145-FEDER-030389, POCI-01-0145-FEDER-028953, and POCI-01-0145-FEDER-032113). This research was supported in part by the National Science Foundation under grant No.NSF PHY-1748958 through the Kavli Institute for Theoretical Physics program "Better Stars, Better Planets". the research leading to the presented results has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No..338251 (StellarAges). E.C.is funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No..664931. M.N.L.acknowledges support from the ESA PRODEX programme. B.M.and R.A.G. acknowledge the support received from CNES through the PLATO grants. A. S.is partially supported by grants ESP2017-82674-R (Spanish Government) and 2017-SGR-1131 (Generalitat de Catalunya). D.V.gratefully acknowledges the support of the STFC via an Ernest Rutherford Fellowship (grant ST/P003850/1). V. A.and S.G.S. acknowledge support from FCT through Investigador FCT contracts No..IF/00650/2015/CP1273/CT0001 and No..IF/00028/2014/CP1215/CT0002, respectively. S. B. acknowledges NSF grant AST-1514676 and NASA grant NNX16AI09G. S.M..acknowledges support from the Spanish Ministry through the Ramon y Cajal fellowship No. RYC-2015-17697. M.B.N..acknowledges support from NYUAD Institute grant G1502. S.R..acknowledges support from the DFG priority program SPP 1992 "Exploring the Diversity of Extrasolar Planets (RE 2694/5-1)". M.Y., Z.C.O., and S. O. acknowledge the Scientific and Technological Research Council of Turkey (TUBITAK:118F352). D.H. acknowledges support by the National Aeronautics and Space Administration (80NSSC18K1585, 80NSSC19K0379) awarded through the TESS Guest Investigator Program. M.S.C. is supported in the form of a work contract funded by FCT (CEECIND/02619/2017). H.K. acknowledges support from the European Social Fund via the Lithuanian Science Council grant No. 09.3.3-LMT-K-712-01-0103.

Published
2019

40. HAYDN - High-precision AsteroseismologY of DeNse stellar fields

Author

Giampaolo Piotto, Igor Soszyński, Marc-Antoine Dupret, Frank Grundahl, Valerio Nascimbeni, Demetrio Magrin, Andrea Miglio, Cristina Chiappini, Silvia Toonen, Arlette Noels, Gaël Buldgen, Eline Tolstoy, Eric Michel, William Chantereau, Nadège Lagarde, Amaury H. M. J. Triaud, Bill Chaplin, Karsten Brogaard, Angela Bragaglia, Ted Mackereth, Mark Gieles, Léo Girardi, Georges Meynet, Rob Izzard, Roberto Ragazzoni, Patrick Eggenberger, Benoit Mosser, Nate Bastian, Daisuke Kawata, Josefina Montalbán, Christoffer Karoff, Fiorenzo Vincenzo, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), European Commission, International Space Science Institute, Science and Technology Facilities Council (UK), Swiss National Science Foundation, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Miglio A., Girardi L., Grundahl F., Mosser B., Bastian N., Bragaglia A., Brogaard K., Buldgen G., Chantereau W., Chaplin W., Chiappini C., Dupret M.-A., Eggenberger P., Gieles M., Izzard R., Kawata D., Karoff C., Lagarde N., Mackereth T., Magrin D., Meynet G., Michel E., Montalban J., Nascimbeni V., Noels A., Piotto G., Ragazzoni R., Soszynski I., Tolstoy E., Toonen S., Triaud A., Vincenzo F., and Low Energy Astrophysics (API, FNWI)

Subjects
bulge [Galaxy], Astrophysics::Cosmology and Extragalactic Astrophysics, Globular cluster, low-mass, gGlobular clusters, galaxy: bulge, galaxies: dwarf, asteroseismology [stars], 7. Clean energy, 01 natural sciences, Asteroseismology, Galaxy: bulge, Bulge, low-mass [Stars], Globular clusters, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Stars: low-mass, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, dwarf, Physics, 010308 nuclear & particles physics, Galaxies: dwarf, bulge, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Galaxies, Stars, dwarf [Galaxies], Galaxy, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Miglio, A., et al., In the last decade, the Kepler and CoRoT space-photometry missions have demonstrated the potential of asteroseismology as a novel, versatile and powerful tool to perform exquisite tests of stellar physics, and to enable precise and accurate characterisations of stellar properties, with impact on both exoplanetary and Galactic astrophysics. Based on our improved understanding of the strengths and limitations of such a tool, we argue for a new small/medium space mission dedicated to gathering high-precision, high-cadence, long photometric series in dense stellar fields. Such a mission will lead to breakthroughs in stellar astrophysics, especially in the metal poor regime, will elucidate the evolution and formation of open and globular clusters, and aid our understanding of the assembly history and chemodynamics of the Milky Way’s bulge and a few nearby dwarf galaxies., AM, JM and FV acknowledge support from the European Research Council Consolidator Grant funding scheme (project ASTEROCHRONOMETRY, G.A. n. 772293, http://www.asterochronometry.eu). AM, BM and LG are grateful to the International Space Science Institute (ISSI) for support provided to the asteroSTEP ISSI International Team. AM and WJC acknowledge the support of the UK Science and Technology Facilities Council (STFC). GB is sponsored by the Swiss National Science Foundation (project number 200020 − 172505). WC acknowledges funding from the Swiss National Science Foundation under grant P400P2_183846. We thank G. R. Davies for providing the power spectra used in Fig. 1. N.L. acknowledges financial support from “Programme National de Physique Stellaire” (PNPS) of CNRS/INSU, France. CC acknowledges partial support from DFG Grant CH1188/2-1 and from the ChETEC COST Action (CA16117), supported by COST (European Cooperation in Science and Technology).

Published
2019

41. New light on the Gaia DR2 parallax zero-point: influence of the asteroseismic approach, in and beyond the Kepler field

Author

Anthony G. A. Brown, Frédéric Arenou, Kevin Belkacem, Thaíse S. Rodrigues, David Katz, Thomas S. H. North, Andrea Miglio, Luca Casagrande, Diego Bossini, Yvonne Elsworth, Guy R. Davies, Antonella Vallenari, Benoit Mosser, Tristan Cantat-Gaudin, William J. Chaplin, Léo Girardi, Saniya Khan, B. M. Rendle, Stellar Astrophysics Centre [Aarhus] (SAC), Aarhus University [Aarhus], Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Research School of Astronomy and Astrophysics [Canberra] (RSAA), Australian National University (ANU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), School of Physics and Astronomy, University of Birmingham [Birmingham], PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, Cepheid variable, FOS: Physical sciences, asteroseismology, Astrophysics, 010501 environmental sciences, 01 natural sciences, Kepler, Asteroseismology, stars: low-mass, SYSTEMS, 0103 physical sciences, OSCILLATIONS, low-mass [stars], 010303 astronomy & astrophysics, Red clump, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], MASS-LOSS, Astronomy and Astrophysics, Astrometry, 010601 ecology, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, GIANTS, parallaxes, astrometry, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], CLUSTERS, RADII, Parallax, STARS, Open cluster
Abstract

The importance of studying the Gaia DR2 parallax zero-point by external means was underlined by Lindegren et al. (2018), and initiated by several works making use of Cepheids, eclipsing binaries, and asteroseismology. Despite a very efficient elimination of basic-angle variations, a small fluctuation remains and shows up as a small offset in the Gaia DR2 parallaxes. By combining astrometric, asteroseismic, spectroscopic, and photometric constraints, we undertake a new analysis of the Gaia parallax offset for nearly 3000 red-giant branch (RGB) and 2200 red clump (RC) stars observed by Kepler, as well as about 500 and 700 red giants (both RGB and RC) selected by the K2 Galactic Archaeology Program in campaigns 3 and 6. Engaging into a thorough comparison of the astrometric and asteroseismic parallaxes, we are able to highlight the influence of the asteroseismic method, and measure parallax offsets in the Kepler field that are compatible with independent estimates from literature and open clusters. Moreover, adding the K2 fields to our investigation allows us to retrieve a clear illustration of the positional dependence of the zero-point, in general agreement with the information provided by quasars. Lastly, we initiate a two-step methodology to make progress in the simultaneous calibration of the asteroseismic scaling relations and of the Gaia DR2 parallax offset, which will greatly benefit from the gain in precision with the third Data Release of Gaia., Comment: 15 pages, 17 figures, Accepted for publication in A&A

Published
2019

42. He abundances in disc galaxies -- I. Predictions from cosmological chemodynamical simulations

Author

Josefina Montalbán, Fiorenzo Vincenzo, J. Ted Mackereth, Andrea Miglio, and Chiaki Kobayashi

Subjects
Physics, 010308 nuclear & particles physics, Star formation, Metallicity, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Disc galaxy, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Interstellar medium, Supernova, Space and Planetary Science, Bulge, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Galaxy formation and evolution, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We investigate how the stellar and gas-phase He abundances evolve as functions of time within simulated star-forming disc galaxies with different star formation histories. We make use of a cosmological chemodynamical simulation for galaxy formation and evolution, which includes star formation, as well as energy and chemical enrichment feedback from asymptotic giant branch stars, core-collapse supernovae, and Type Ia supernovae. The predicted relations between the He mass fraction, $Y$, and the metallicity, $Z$, in the interstellar medium of our simulated disc galaxies depend on the past galaxy star formation history. In particular, $dY/dZ$ is not constant and evolves as a function of time, depending on the specific chemical element that we choose to trace $Z$; in particular, $dY/dX_{\text{O}}$ and $dY/dX_{\text{C}}$ increase as functions of time, whereas $dY/dX_{\text{N}}$ decreases. In the gas-phase, we find negative radial gradients of $Y$, due to the inside-out growth of our simulated galaxy discs as a function of time; this gives rise to longer chemical enrichment time scales in the outer galaxy regions, where we find lower average values for $Y$ and $Z$. Finally, by means of chemical evolution models, in the galactic bulge and inner disc, we predict steeper $Y$ versus age relations at high $Z$ than in the outer galaxy regions. We conclude that, for calibrating the assumed $Y$-$Z$ relation in stellar models, C, N, and C+N are better proxies for the metallicity than O, because they show steeper and less scattered relations., Accepted for publication in A&A

Published
2019

43. AIMS - a new tool for stellar parameter determinations using asteroseismic constraints

Author

Laura J. A. Scott, Tiago L. Campante, William J. Chaplin, Daniel R. Reese, Warrick H. Ball, Jiri Smetana, Mikkel N. Lund, Gaël Buldgen, Arlette Noels, B. M. Rendle, Richard Scuflaire, Andrea Miglio, James S. Kuszlewicz, Guy R. Davies, Benard Nsamba, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
stars, oscillations [stars], fundamental parameters -stars, fundamental parameters [stars], FOS: Physical sciences, Scale (descriptive set theory), 01 natural sciences, Asteroseismology, Synthetic data, symbols.namesake, Consistency (statistics), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), [PHYS]Physics [physics], Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Markov chain Monte Carlo, Grid, Bayesian statistics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, oscillations, symbols, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Algorithm, QB799, Interpolation
Abstract

A key aspect in the determination of stellar properties is the comparison of observational constraints with predictions from stellar models. Asteroseismic Inference on a Massive Scale (AIMS) is an open source code that uses Bayesian statistics and a Markov Chain Monte Carlo approach to find a representative set of models that reproduce a given set of classical and asteroseismic constraints. These models are obtained by interpolation on a pre-calculated grid, thereby increasing computational efficiency. We test the accuracy of the different operational modes within AIMS for grids of stellar models computed with the Li\`ege stellar evolution code (main sequence and red giants) and compare the results to those from another asteroseismic analysis pipeline, PARAM. Moreover, using artificial inputs generated from models within the grid (assuming the models to be correct), we focus on the impact on the precision of the code when considering different combinations of observational constraints (individual mode frequencies, period spacings, parallaxes, photospheric constraints,...). Our tests show the absolute limitations of precision on parameter inferences using synthetic data with AIMS, and the consistency of the code with expected parameter uncertainty distributions. Interpolation testing highlights the significance of the underlying physics to the analysis performance of AIMS and provides caution as to the upper limits in parameter step size. All tests demonstrate the flexibility and capability of AIMS as an analysis tool and its potential to perform accurate ensemble analysis with current and future asteroseismic data yields., Comment: Accepted for publication in MNRAS. 17 pages, 17 figures

Published
2019

44. Dynamical heating across the Milky Way disc using APOGEE and Gaia

Author

Marie Martig, Steven R. Majewski, Diane Feuillet, Jennifer Sobeck, Jo Bovy, William J. Chaplin, David L. Nidever, Victor Silva Aguirre, J. Tayar, Ricardo P. Schiavon, Marc H. Pinsonneault, Katia Cunha, Gail Zasowski, Wilma H. Trick, J. Ted Mackereth, Henry W. Leung, and Andrea Miglio

Subjects
010308 nuclear & particles physics, FOS: Physical sciences, Library science, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, kinematics and dynamics [Galaxy], 01 natural sciences, Astrophysics - Astrophysics of Galaxies, evolution [Galaxy], disc [Galaxy], formation [Galaxy], 13. Climate action, Space and Planetary Science, Research council, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, stellar content [Galaxy], Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, QC, Mathematics, QB
Abstract

The kinematics of the Milky Way disc as a function of age are well measured at the solar radius, but have not been studied over a wider range of Galactocentric radii. Here, we measure the kinematics of mono-age, mono-$\mathrm{[Fe/H]}$ populations in the low and high $\mathrm{[\alpha/Fe]}$ discs between $4 \lesssim R \lesssim 13$ kpc and $|z| \lesssim 2$ kpc using 65,719 stars in common between APOGEE DR14 and $\it{Gaia}$ DR2 for which we estimate ages using a Bayesian neural network model trained on asteroseismic ages. We determine the vertical and radial velocity dispersions, finding that the low and high $\mathrm{[\alpha/Fe]}$ discs display markedly different age--velocity-dispersion relations (AVRs) and shapes $\sigma_z/\sigma_R$. The high $\mathrm{[\alpha/Fe]}$ disc has roughly flat AVRs and constant $\sigma_z/\sigma_R = 0.64\pm 0.04$, whereas the low $\mathrm{[\alpha/Fe]}$ disc has large variations in this ratio which positively correlate with the mean orbital radius of the population at fixed age. The high $\mathrm{[\alpha/Fe]}$ disc component's flat AVRs and constant $\sigma_z/\sigma_R$ clearly indicates an entirely different heating history. Outer disc populations also have flatter radial AVRs than those in the inner disc, likely due to the waning effect of spiral arms. Our detailed measurements of AVRs and $\sigma_z/\sigma_R$ across the disc indicate that low $\mathrm{[\alpha/Fe]}$, inner disc ($R \lesssim 10\,\mathrm{kpc}$) stellar populations are likely dynamically heated by both giant molecular clouds and spiral arms, while the observed trends for outer disc populations require a significant contribution from another heating mechanism such as satellite perturbations. We also find that outer disc populations have slightly positive mean vertical and radial velocities, likely because they are part of the warped disc., Comment: Accepted for publication in MNRAS - The revised version has various updates to the text following suggestions from the referee, but general results remain the same. Code is available https://github.com/jmackereth/monoage-velocity-dispersion, and the APOGEE DR14 age catalogue can be found alongside a paper summary http://www.astro.ljmu.ac.uk/~astjmack/dynamical-heating.html

Published
2019
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45. Insights from the APOKASC determination of the evolutionary state of red-giant stars by consolidation of different methods

Author

J. Tayar, Marc H. Pinsonneault, Aldo Serenelli, Yvonne Elsworth, B. Mosser, James S. Kuszlewicz, Saskia Hekker, Jennifer A. Johnson, Andrea Miglio, M. Vrard, Dennis Stello, Marc Hon, Thomas Kallinger, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
oscillations [stars], Red giant, CLUMP, Milky Way, FOS: Physical sciences, Astrophysics, asteroseismology, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Kepler, Asteroseismology, MAGNETIC-FIELDS, 0103 physical sciences, OSCILLATIONS, Astrophysics::Solar and Stellar Astrophysics, Stellar structure, low-mass [stars], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, [PHYS]Physics [physics], Consolidation (soil), 010308 nuclear & particles physics, Astronomy and Astrophysics, Observable, HELIUM ABUNDANCE, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, evolution [stars], MODES, Astrophysics::Earth and Planetary Astrophysics, CLUSTERS, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

The internal working of low-mass stars is of great significance to both the study of stellar structure and the history of the Milky Way. Asteroseismology has the power to directly sense the internal structure of stars and allows for the determination of the evolutionary state -- i.e. has helium burning commenced or is the energy generated only by the fusion in the hydrogen-burning shell? We use observational data from red-giant stars in a combination (known as APOKASC) of asteroseismology (from the \textit{Kepler} mission) and spectroscopy (from SDSS/APOGEE). The new feature of the analysis is that the APOKASC evolutionary state determination is based on the comparison of diverse approaches to the investigation of the frequency-power spectrum. The high level of agreement between the methods is a strong validation of the approaches. Stars for which there is not a consensus view are readily identified. The comparison also facilitates the identification of unusual stars including those that show evidence for very strong coupling between p and g cavities. The comparison between the classification based on the spectroscopic data and asteroseismic data have led to a new value for the statistical uncertainty in APOGEE temperatures. These consensus evolutionary states will be used as an input for methods that derive masses and ages for these stars based on comparison of observables with stellar evolutionary models (`grid-based modeling') and as a training set for machine-learning and other data-driven methods of evolutionary state determination, 19 pages, 10 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society

Published
2019
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46. The K2 Galactic Caps Project – going beyond the Kepler field and ageing the Galactic disc

Author

Paula Jofre, J. A. Johnson, Andrea Miglio, B. M. Rendle, R. A. Garcia, Savita Mathur, Thaíse S. Rodrigues, William J. Chaplin, Marica Valentini, Riki Lane, Katia Cunha, Benoit Mosser, Mikkel N. Lund, Yvonne Elsworth, Cristina Chiappini, L. Girardi, Saniya Khan, Luca Casagrande, Christian Nitschelm, A. Gavel, Guy R. Davies, Laura Magrini, Diane Feuillet, C. C. Worley, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
THICK DISK, asteroseismology -stars, FOS: Physical sciences, Library science, Astrophysics::Cosmology and Extragalactic Astrophysics, late type [stars], stellar content, 01 natural sciences, STELLAR POPULATIONS, 0103 physical sciences, OSCILLATIONS, Astrophysics::Solar and Stellar Astrophysics, Cost action, structure, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Mathematics, [PHYS]Physics [physics], SOLAR-TYPE STARS, 010308 nuclear & particles physics, European research, Asteroseismology, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, GALAXY, COLD DARK-MATTER, RED GIANTS, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Research council, Astrophysics of Galaxies (astro-ph.GA), MILKY, Christian ministry, Astrophysics::Earth and Planetary Astrophysics, late type -Galaxy, stellar content, structure [Galaxy], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], NEARBY STARS
Abstract

Analyses of data from spectroscopic and astrometric surveys have led to conflicting results concerning the vertical characteristics of the Milky Way. Ages are often used to provide clarity, but typical uncertainties of $>$ 40\,\% restrict the validity of the inferences made. Using the \textit{Kepler} APOKASC sample for context, we explore the global population trends of two K2 campaign fields (3 and 6), which extend further vertically out of the Galactic plane than APOKASC. We analyse the properties of red giant stars utilising three asteroseismic data analysis methods to cross-check and validate detections. The Bayesian inference tool PARAM is used to determine the stellar masses, radii and ages. Evidence of a pronounced red giant branch bump and an [$\alpha$/Fe] dependence on the position of the red clump is observed from the radii distribution of the K2 fields. Two peaks in the age distribution centred at $\sim$5 and and $\sim$12 Gyr are found using a sample with $\sigma_{\rm{age}}$ $$ 0.1) [$\alpha$/Fe] stars. As a function of vertical distance from the Galactic mid-plane ($|Z|$), the age distribution shows a transition from a young to old stellar population with increasing $|Z|$ for the K2 fields. Further coverage of campaign targets with high resolution spectroscopy is required to increase the yield of precise ages achievable with asteroseismology., Comment: 17 pages, 16 figures. Accepted to MNRAS 01/08/2019. Updated manuscript

Published
2019
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47. Testing asteroseismology with Gaia DR2:hierarchical models of the Red Clump

Author

Anthony G. A. Brown, Keith Hawkins, Rafael A. García, Thomas S. H. North, Timothy R. Bedding, Andrea Miglio, Guy R. Davies, William J. Chaplin, Oliver J. Hall, Yvonne Elsworth, and Saniya Khan

Subjects
Offset (computer science), PLANET HOSTS, ACCURACY, fundamental parameters [stars], FOS: Physical sciences, Astrophysics, asteroseismology, MASS, 01 natural sciences, Asteroseismology, K band, 0103 physical sciences, Calibration, OSCILLATIONS, 010303 astronomy & astrophysics, Red clump, Solar and Stellar Astrophysics (astro-ph.SR), Physics, 010308 nuclear & particles physics, Cosmic distance ladder, Astronomy and Astrophysics, SOLAR-TYPE, GIANT STARS, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, parallaxes, POPULATIONS, ABSOLUTE MAGNITUDE, Parallax, STELLAR PHOTOMETRY, RADII, statistics [stars]
Abstract

Asteroseismology provides fundamental stellar parameters independent of distance, but subject to systematics under calibration. Gaia DR2 has provided parallaxes for a billion stars, which are offset by a parallax zero-point. Red Clump (RC) stars have a narrow spread in luminosity, thus functioning as standard candles to calibrate these systematics. This work measures how the magnitude and spread of the RC in the Kepler field are affected by changes to temperature and scaling relations for seismology, and changes to the parallax zero-point for Gaia. We use a sample of 5576 RC stars classified through asteroseismology. We apply hierarchical Bayesian latent variable models, finding the population level properties of the RC with seismology, and use those as priors on Gaia parallaxes to find the parallax zero-point offset. We then find the position of the RC using published values for the zero-point. We find a seismic temperature insensitive spread of the RC of ~0.03 mag in the 2MASS K band and a larger and slightly temperature-dependent spread of ~0.13 mag in the Gaia G band. This intrinsic dispersion in the K band provides a distance precision of ~1% for RC stars. Using Gaia data alone, we find a mean zero-point of -41 $\pm$ 10 $\mu$as. This offset yields RC absolute magnitudes of -1.634 $\pm$ 0.018 in K and 0.546 $\pm$ 0.016 in G. Obtaining these same values through seismology would require a global temperature shift of ~-70 K, which is compatible with known systematics in spectroscopy., Comment: Accepted for publication in MNRAS

Published
2019

48. The Asteroseismic Target List (ATL) for solar-like oscillators observed in 2-minute cadence with the Transiting Exoplanet Survey Satellite (TESS)

Author

V. Silva Aguirre, O. L. Creevey, T. L. Campante, J. Christensen-Dalsgaard, D. W. Latham, M. N. Lund, T. S. Metcalfe, H. Kjeldsen, Rasmus Handberg, S. Basu, T. Appourchaux, Warrick H. Ball, R. Vanderspek, George R. Ricker, Timothy R. Bedding, Andrea Miglio, Daniel Huber, William J. Chaplin, Rafael A. García, S. D. Kawaler, A. M. Serenelli, Guy R. Davies, D. Stello, Mathew Schofield, Department of Psychology, St John's University, Cognition, Langues, Langage, Ergonomie (CLLE-ERSS), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Toulouse - Jean Jaurès (UT2J)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Département des Sciences et Gestion de l'Environnement/Océanologie [Liège], Université de Liège, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy, Yale University [New Haven], Sydney Institute for Astronomy (SIfA), The University of Sydney, Danish AsteroSeismology Centre (DASC), Aarhus University [Aarhus], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Research institute of Computer Vision and Robotics [Girona] (VICOROB), Universitat de Girona (UdG), Department of Physics and Astronomy [Aarhus], Department of Physics and Astronomy [Iowa City], and University of Iowa [Iowa City]

Subjects
oscillations [stars], Source code, instruments [space vehicles], media_common.quotation_subject, fundamental parameters [stars], FOS: Physical sciences, Astrophysics, 01 natural sciences, Asteroseismology, surveys, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), media_common, Physics, 010308 nuclear & particles physics, Subgiant, Astronomy and Astrophysics, Exoplanet, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Satellite, Cadence, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], catalogs
Abstract

We present the target list of solar-type stars to be observed in short-cadence (2-min) for asteroseismology by the NASA Transiting Exoplanet Survey Satellite (TESS) during its 2-year nominal survey mission. The solar-like Asteroseismic Target List (ATL) is comprised of bright, cool main-sequence and subgiant stars and forms part of the larger target list of the TESS Asteroseismic Science Consortium (TASC). The ATL uses Gaia DR2 and the Extended Hipparcos Compilation (XHIP) to derive fundamental stellar properties, calculate detection probabilities and produce a rank-ordered target list. We provide a detailed description of how the ATL was produced and calculate expected yields for solar-like oscillators based on the nominal photometric performance by TESS. We also provide publicly available source code which can be used to reproduce the ATL, thereby enabling comparisons of asteroseismic results from TESS with predictions from synthetic stellar populations., Comment: 13 pages, 11 figures; accepted for publication in Astrophysical Journal Supplement Series

Published
2019
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49. Seismic performance

Author

R. Samadi, Andrea Miglio, B. Mosser, Guy R. Davies, M. J. Goupil, L. Girardi, E. Michel, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, INAF - Osservatorio Astronomico di Padova (OAPD), and Istituto Nazionale di Astrofisica (INAF)

Subjects
oscillations [Stars], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: interiors, 01 natural sciences, Asteroseismology, Apparent magnitude, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, stars: evolution, 010303 astronomy & astrophysics, Scaling, Stellar evolution, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, interiors [stars], 010308 nuclear & particles physics, Astronomy and Astrophysics, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Stellar physics, evolution [stars], Content (measure theory), stars: oscillations, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Main sequence
Abstract

Asteroseismology is a unique tool that can be used to study the interior of stars and hence deliver unique information for the studiy of stellar physics, stellar evolution, and Galactic archaeology. We aim to develop a simple model of the information content of asteroseismology and to characterize the ability and precision with which fundamental properties of stars can be estimated for different space missions. We defined and calibrated metrics of the seismic performance. The metrics, expressed by a seismic index ${\mathcal{E}$ defined by simple scaling relations, are calculated for an ensemble of stars. We studied the relations between the properties of mission observations, fundamental stellar properties, and the performance index. We also defined thresholds for asteroseismic detection and measurement of different stellar properties We find two regimes of asteroseismic performance: the first where the signal strength is dominated by stellar properties and not by observational noise; and the second where observational properties dominate. Typically, for evolved stars, stellar properties provide the dominant terms in estimating the information content, while main sequence stars fall in the regime where the observational properties, especially stellar magnitude, dominate. We estimate scaling relations to predict ${\mathcal{E}$ with an intrinsic scatter of around 21%. Incidentally, the metrics allow us to distinguish stars burning either hydrogen or helium. Our predictions will help identify the nature of the cohort of existing and future asteroseismic observations. In addition, the predicted performance for PLATO will help define optimal observing strategies for defined scientific goals., Accepted in A&A

Published
2019

50. Asteroseismic constraints on active latitudes of solar-type stars:HD173701 has active bands at higher latitudes than the Sun

Author

Guy R. Davies, Andrea Miglio, Alexandra E. L. Thomas, William J. Chaplin, Ângela R. G. Santos, Tiago L. Campante, Yvonne Elsworth, Rachel Howe, and Margarida S. Cunha

Subjects
FOS: Physical sciences, Flux, Astrophysics, Spatial distribution, 01 natural sciences, Asteroseismology, Latitude, Activity - stars, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Asteroseismology - stars, Individual (HD 173701), 010308 nuclear & particles physics, Oscillation, Astronomy and Astrophysics, Magnetic flux, Azimuth, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics
Abstract

We present a new method for determining the location of active bands of latitude on solar-type stars, which uses stellar-cycle-induced frequency shifts of detectable solar-like oscillations. When near-surface activity is distributed in a non-homogeneous manner, oscillation modes of different angular degree and azimuthal order will have their frequencies shifted by different amounts. We use this simple concept, coupled to a model for the spatial distribution of the near-surface activity, to develop two methods that use the frequency shifts to infer minimum and maximum latitudes for the active bands. Our methods respond to the range in latitude over which there is significant magnetic flux present, over and above weak basal ephemeral flux levels. We verify that we are able to draw accurate inferences in the solar case, using Sun-as-a-star helioseismic data and artificial data. We then apply our methods to Kepler data on the solar analogue HD173701, and find that its active bands straddle a much wider range in latitude than do the bands on the Sun., 13 pages, 15 figures, MNRAS accepted

Published
2019

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