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Your search keyword '"Giusi Micela"' showing total 3 results
Start Over Author "Giusi Micela" Topic astronomy and astrophysics
3 results on '"Giusi Micela"'

1. The GAPS programme at TNG XXXIX. Multiple molecular species in the atmosphere of the warm giant planet WASP-80 b unveiled at high resolution with GIANO-B

Author

Ilaria Carleo, Paolo Giacobbe, Gloria Guilluy, Patricio E. Cubillos, Aldo S. Bonomo, Alessandro Sozzetti, Matteo Brogi, Siddharth Gandhi, Luca Fossati, Diego Turrini, Katia Biazzo, Francesco Borsa, Antonino F. Lanza, Luca Malavolta, Antonio Maggio, Luigi Mancini, Giusi Micela, Lorenzo Pino, Ennio Poretti, Monica Rainer, Gaetano Scandariato, Eugenio Schisano, Gloria Andreuzzi, Andrea Bignamini, Rosario Cosentino, Aldo Fiorenzano, Avet Harutyunyan, Emilio Molinari, Marco Pedani, Seth Redfield, and Hristo Stoev

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Exoplanet atmospheres, Exoplanet astronomy, Exoplanet atmospheric composition, Exoplanet detection methods, Transit photometry, High resolution spectroscopy, Molecular spectroscopy, Settore FIS/05, FOS: Physical sciences, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics - Earth and Planetary Astrophysics
Abstract

Detections of molecules in the atmosphere of gas giant exoplanets allow us to investigate the physico-chemical properties of the atmospheres. Their inferred chemical composition is used as tracer of planet formation and evolution mechanisms. Currently, an increasing number of detections is showing a possible rich chemistry of the hotter gaseous planets, but whether this extends to cooler giants is still unknown. We observed four transits of WASP-80 b, a warm transiting giant planet orbiting a late-K dwarf star with the near-infrared GIANO-B spectrograph installed at the Telescopio Nazionale Galileo and performed high resolution transmission spectroscopy analysis. We report the detection of several molecular species in its atmosphere. Combining the four nights and comparing our transmission spectrum to planetary atmosphere models containing the signature of individual molecules within the cross-correlation framework, we find the presence of H2O, CH4, NH3 and HCN with high significance, tentative detection of CO2, and inconclusive results for C2H2 and CO. A qualitative interpretation of these results, using physically motivated models, suggests an atmosphere consistent with solar composition and the presence of disequilibrium chemistry and we therefore recommend the inclusion of the latter in future modelling of sub-1000K planets., Comment: 12 pages, 4 figures. AJ, Accepted July 11th, 2022

Published
2022

2. Identifying Exoplanets with Deep Learning. IV. Removing Stellar Activity Signals from Radial Velocity Measurements Using Neural Networks

Author

Zoe. L. de Beurs, Andrew Vanderburg, Christopher J. Shallue, Xavier Dumusque, Andrew Collier Cameron, Christopher Leet, Lars A. Buchhave, Rosario Cosentino, Adriano Ghedina, Raphaëlle D. Haywood, Nicholas Langellier, David W. Latham, Mercedes López-Morales, Michel Mayor, Giusi Micela, Timothy W. Milbourne, Annelies Mortier, Emilio Molinari, Francesco Pepe, David F. Phillips, Matteo Pinamonti, Giampaolo Piotto, Ken Rice, Dimitar Sasselov, Alessandro Sozzetti, Stéphane Udry, Christopher A. Watson, De Beurs, ZL [0000-0002-7564-6047], Vanderburg, A [0000-0001-7246-5438], Shallue, CJ [0000-0002-7585-9974], Dumusque, X [0000-0002-9332-2011], Cameron, AC [0000-0002-8863-7828], Leet, C [0000-0003-2369-0481], Buchhave, LA [0000-0003-1605-5666], Cosentino, R [0000-0003-1784-1431], Ghedina, A [0000-0003-4702-5152], Haywood, RD [0000-0001-9140-3574], Langellier, N [0000-0003-2107-3308], Latham, DW [0000-0001-9911-7388], López-Morales, M [0000-0003-3204-8183], Mayor, M [0000-0002-9352-5935], Micela, G [0000-0002-9900-4751], Milbourne, TW [0000-0001-5446-7712], Mortier, A [0000-0001-7254-4363], Molinari, E [0000-0002-1742-7735], Phillips, DF [0000-0001-5132-1339], Pinamonti, M [0000-0002-4445-1845], Piotto, G [0000-0002-9937-6387], Rice, K [0000-0002-6379-9185], Sasselov, D [0000-0001-7014-1771], Sozzetti, A [0000-0002-7504-365X], Udry, S [0000-0001-7576-6236], Apollo - University of Cambridge Repository, Apollo-University Of Cambridge Repository, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science

Subjects
QA75, FOS: Computer and information sciences, Radial velocity, Computer Science - Machine Learning, astro-ph.SR, Exoplanet astronomy, QA75 Electronic computers. Computer science, cs.LG, FOS: Physical sciences, Machine Learning (cs.LG), QB Astronomy, Instrumentation and Methods for Astrophysics (astro-ph.IM), QC, Solar and Stellar Astrophysics (astro-ph.SR), QB, Earth and Planetary Astrophysics (astro-ph.EP), The Solar System, Exoplanets, and Astrobiology, Astronomy and Astrophysics, DAS, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, astro-ph.EP, Convolutional neural networks, Astrophysics - Instrumentation and Methods for Astrophysics, astro-ph.IM, Astrophysics - Earth and Planetary Astrophysics
Abstract

Exoplanet detection with precise radial velocity (RV) observations is currently limited by spurious RV signals introduced by stellar activity. We show that machine learning techniques such as linear regression and neural networks can effectively remove the activity signals (due to starspots/faculae) from RV observations. Previous efforts focused on carefully filtering out activity signals in time using modeling techniques like Gaussian Process regression (e.g. Haywood et al. 2014). Instead, we systematically remove activity signals using only changes to the average shape of spectral lines, and no information about when the observations were collected. We trained our machine learning models on both simulated data (generated with the SOAP 2.0 software; Dumusque et al. 2014) and observations of the Sun from the HARPS-N Solar Telescope (Dumusque et al. 2015; Phillips et al. 2016; Collier Cameron et al. 2019). We find that these techniques can predict and remove stellar activity from both simulated data (improving RV scatter from 82 cm/s to 3 cm/s) and from more than 600 real observations taken nearly daily over three years with the HARPS-N Solar Telescope (improving the RV scatter from 1.753 m/s to 1.039 m/s, a factor of ~ 1.7 improvement). In the future, these or similar techniques could remove activity signals from observations of stars outside our solar system and eventually help detect habitable-zone Earth-mass exoplanets around Sun-like stars., Comment: 28 pages, 14 figures, Accepted for publication in the Astronomical Journal

Published
2020
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3. CSI 2264: Characterizing Accretion-Burst Dominated Light Curves for Young Stars in NGC 2264

Author

John Stauffer, Ann Marie Cody, Annie Baglin, Silvia Alencar, Luisa Rebull, Lynne A. Hillenbrand, Laura Venuti, Neal J. Turner, John Carpenter, Peter Plavchan, Krzysztof Findeisen, Sean Carey, Susan Terebey, María Morales-Calderón, Jerome Bouvier, Giusi Micela, Ettore Flaccomio, Inseok Song, Rob Gutermuth, Lee Hartmann, Nuria Calvet, Barbara Whitney, David Barrado, Frederick J. Vrba, Kevin Covey, William Herbst, Gabor Furesz, Suzanne Aigrain, Fabio Favata, Spitzer Science Center, California Institute of Technology (CALTECH), 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), Departamento de Fisica - ICEx, Universidade Federal de Minas Gerais, Caltech Department of Astronomy [Pasadena], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), University of Georgia [USA], European Space Astronomy Centre (ESAC), European Space Agency (ESA), Lowell Observatory [Flagstaff], Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, School of Physics, University of Exeter, Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), University of Exeter, and Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA)

Subjects
Physics, [PHYS]Physics [physics], Young stellar object, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Magnetosphere, Flux, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Light curve, Accretion (astrophysics), Luminosity, Stars, Wavelength, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics
Abstract

Based on more than four weeks of continuous high cadence photometric monitoring of several hundred members of the young cluster NGC 2264 with two space telescopes, NASA's Spitzer and the CNES CoRoT (Convection, Rotation, and planetary Transits), we provide high quality, multi-wavelength light curves for young stellar objects (YSOs) whose optical variability is dominated by short duration flux bursts, which we infer are due to enhanced mass accretion rates. These light curves show many brief -- several hour to one day -- brightenings at optical and near-infrared (IR) wavelengths with amplitudes generally in the range 5-50% of the quiescent value. Typically, a dozen or more of these bursts occur in a thirty day period. We demonstrate that stars exhibiting this type of variability have large ultraviolet (UV) excesses and dominate the portion of the u-g vs. g-r color-color diagram with the largest UV excesses. These stars also have large Halpha equivalent widths, and either centrally peaked, lumpy Halpha emission profiles or profiles with blue-shifted absorption dips associated with disk or stellar winds. Light curves of this type have been predicted for stars whose accretion is dominated by Rayleigh-Taylor instabilities at the boundary between their magnetosphere and inner circumstellar disk, or where magneto-rotational instabilities modulate the accretion rate from the inner disk. Amongst the stars with the largest UV excesses or largest Halpha equivalent widths, light curves with this type of variability greatly outnumber light curves with relatively smooth sinusoidal variations associated with long-lived hot spots. We provide quantitative statistics for the average duration and strength of the accretion bursts and for the fraction of the accretion luminosity associated with these bursts., Comment: Accepted for publication in AJ. 39 pages; 6 tables; 25 figures, many of which are highly degraded to meet size limits. Please download the regular resolution version at http://web.ipac.caltech.edu/staff/amc/staufferetal2014.pdf

Published
2014

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