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1. The SDSS-V Black Hole Mapper Reverberation Mapping Project: C iv Broad Absorption Line Acceleration in the Quasar SBS 1408+544

Author: Robert Wheatley, Catherine J. Grier, Patrick B. Hall, W. N. Brandt, Jonah Lotz, D. P. Schneider, Jonathan R. Trump, Yue Shen, Lucas M. Seaton, Scott F. Anderson, Matthew J. Temple, Roberto Assef, Logan B. Fries, Y. Homayouni, Darshan Kakkad, Anton M. Koekemoer, Mary Loli Martínez-Aldama, C. Alenka Negrete, Claudio Ricci, Dmitry Bizyaev, Joel R. Brownstein, Sean Morrison, and Kaike Pan
Subjects: Broad-absorption line quasar, Quasars, Active galactic nuclei, Astrophysics, QB460-466
Abstract: We present the results of an investigation of a highly variable C iv broad absorption line (BAL) feature in spectra of the quasar SBS 1408+544 ( z = 2.337) that shows a significant shift in velocity over time. This source was observed as a part of the Sloan Digital Sky Survey (SDSS) Reverberation Mapping project and the SDSS-V Black Hole Mapper Reverberation Mapping project, and has been included in two previous studies, both of which identified significant variability in a high-velocity C iv BAL on timescales of just a few days in the quasar rest frame. Using ∼130 spectra acquired over 8 yr of spectroscopic monitoring with SDSS, we have determined that this BAL is not only varying in strength, but is also systematically shifting to higher velocities. Using cross-correlation methods, we measure the velocity shifts (and corresponding acceleration) of the BAL over a wide range of timescales, measuring an overall velocity shift of ${\rm{\Delta }}v=-{683}_{-84}^{+89}$ km s ^−1 over the 8 yr monitoring period. This corresponds to an average rest-frame acceleration of a = 1.04 ${}_{-0.13}^{+0.14}$ cm s ^−2 , though the magnitude of the acceleration on shorter timescales is not constant throughout. We place our measurements in the context of BAL-acceleration models and examine various possible causes of the observed velocity shift.
Published: 2024
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2. The Sloan Digital Sky Survey Reverberation Mapping Project: Key Results

Author: Yue Shen, Catherine J. Grier, Keith Horne, Zachary Stone, Jennifer I. Li, Qian Yang, Yasaman Homayouni, Jonathan R. Trump, Scott F. Anderson, W. N. Brandt, Patrick B. Hall, Luis C. Ho, Linhua Jiang, Patrick Petitjean, Donald P. Schneider, Charling Tao, Fergus. R. Donnan, Yusra AlSayyad, Matthew A. Bershady, Michael R. Blanton, Dmitry Bizyaev, Kevin Bundy, Yuguang Chen, Megan C. Davis, Kyle Dawson, Xiaohui Fan, Jenny E. Greene, Hannes Gröller, Yucheng Guo, Héctor Ibarra-Medel, Yuanzhe Jiang, Ryan P. Keenan, Juna A. Kollmeier, Cassandra Lejoly, Zefeng Li, Axel de la Macorra, Maxwell Moe, Jundan Nie, Graziano Rossi, Paul S. Smith, Wei Leong Tee, Anne-Marie Weijmans, Jiachuan Xu, Minghao Yue, Xu Zhou, Zhimin Zhou, and Hu Zou
Subjects: Reverberation mapping, Surveys, Quasars, Astrophysics, QB460-466
Abstract: We present the final data from the Sloan Digital Sky Survey (SDSS) Reverberation Mapping (RM) project, a precursor to the SDSS-V Black Hole Mapper RM program. This data set includes 11 yr photometric and 7 yr spectroscopic light curves for 849 broad-line quasars over a redshift range of 0.1 < z < 4.5 and a luminosity range of L _bol = 10 ^44−47.5 erg s ^−1 , along with spectral and variability measurements. We report 23, 81, 125, and 110 RM lags (relative to optical continuum variability) for broad H α , H β , Mg ii , and C iv using the SDSS-RM sample, spanning much of the luminosity and redshift ranges of the sample. Using 30 low-redshift RM active galactic nuclei with dynamical-modeling black hole masses, we derive a new estimate of the average virial factor of $\left\langle \mathrm{log}f\right\rangle =0.62\pm 0.07$ for the line dispersion measured from the rms spectrum. The intrinsic scatter of individual virial factors is 0.31 ± 0.07 dex, indicating a factor of 2 systematic uncertainty in RM black hole masses. Our lag measurements reveal significant R – L relations for H β and Mg ii at high redshift, consistent with the latest measurements based on heterogeneous samples. While we are unable to robustly constrain the slope of the R – L relation for C iv given the limited dynamic range in luminosity, we found substantially larger scatter in C iv lags at fixed L _1350 . Using the SDSS-RM lag sample, we derive improved single-epoch (SE) mass recipes for H β , Mg ii , and C iv , which are consistent with their respective RM masses as well as between the SE recipes from two different lines, over the luminosity range probed by our sample. The new H β and Mg ii recipes are approximately unbiased estimators at given RM masses, but there are systematic biases in the C iv recipe. The intrinsic scatter of SE masses around RM masses is ∼0.45 dex for H β and Mg ii , increasing to ∼0.58 dex for C iv .
Published: 2024
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3. Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results

Author: Grisha Zeltyn, Benny Trakhtenbrot, Michael Eracleous, Qian Yang, Paul Green, Scott F. Anderson, Stephanie LaMassa, Jessie Runnoe, Roberto J. Assef, Franz E. Bauer, W. N. Brandt, Megan C. Davis, Sara E. Frederick, Logan B. Fries, Matthew J. Graham, Norman A. Grogin, Muryel Guolo, Lorena Hernández-García, Anton M. Koekemoer, Mirko Krumpe, Xin Liu, Mary Loli Martínez-Aldama, Claudio Ricci, Donald P. Schneider, Yue Shen, Marzena Śniegowska, Matthew J. Temple, Jonathan R. Trump, Yongquan Xue, Joel R. Brownstein, Tom Dwelly, Sean Morrison, Dmitry Bizyaev, Kaike Pan, and Juna A. Kollmeier
Subjects: Quasars, Supermassive black holes, Astrophysics, QB460-466
Abstract: “Changing-look” active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-year Sloan Digital Sky Survey V (SDSS-V) repeated spectroscopy of nearly 29,000 previously known active galactic nuclei (AGNs), combined with dedicated follow-up spectroscopy, and publicly available optical light curves, we have identified 116 CL-AGNs where (at least) one broad emission line has essentially (dis-)appeared, as well as 88 other extremely variable systems. Our CL-AGN sample, with 107 newly identified cases, is the largest reported to date, and includes ∼0.4% of the AGNs reobserved in first-year SDSS-V operations. Among our CL-AGNs, 67% exhibit dimming while 33% exhibit brightening. Our sample probes extreme AGN spectral variability on months to decades timescales, including some cases of recurring transitions on surprisingly short timescales (≲2 months in the rest frame). We find that CL events are preferentially found in lower-Eddington-ratio ( f _Edd ) systems: Our CL-AGNs have a f _Edd distribution that significantly differs from that of a carefully constructed, redshift- and luminosity-matched control sample (Anderson–Darling test yielding p _AD ≈ 6 × 10 ^−5 ; median f _Edd ≈ 0.025 versus 0.043). This preference for low f _Edd strengthens previous findings of higher CL-AGN incidence at lower f _Edd , found in smaller samples. Finally, we show that the broad Mg ii emission line in our CL-AGN sample tends to vary significantly less than the broad H β emission line. Our large CL-AGN sample demonstrates the advantages and challenges in using multi-epoch spectroscopy from large surveys to study extreme AGN variability and physics.
Published: 2024
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4. The Sloan Digital Sky Survey Reverberation Mapping Project: Investigation of Continuum Lag Dependence on Broad-line Contamination and Quasar Properties

Author: Hugh W. Sharp, Y. Homayouni, Jonathan R. Trump, Scott F. Anderson, Roberto J. Assef, W. N. Brandt, Megan C. Davis, Logan B. Fries, Catherine J. Grier, Patrick B. Hall, Keith Horne, Anton M. Koekemoer, Mary Loli Martínez-Aldama, David M. Menezes, Theodore Pena, C. Ricci, Donald P. Schneider, Yue Shen, and Benny Trakhtenbrot
Subjects: Quasars, Active galactic nuclei, Supermassive black holes, Astrophysics, QB460-466
Abstract: This work studies the relationship between accretion-disk size and quasar properties, using a sample of 95 quasars from the Sloan Digital Sky Survey Reverberation Mapping Project with measured lags between the g and i photometric bands. Our sample includes disk lags that are both longer and shorter than predicted by the Shakura and Sunyaev model, requiring explanations that satisfy both cases. Although our quasars each have one lag measurement, we explore the wavelength-dependent effects of diffuse broad-line region (BLR) contamination through our sample’s broad redshift range, 0.1 < z < 1.2. We do not find significant evidence of variable diffuse Fe ii and Balmer nebular emission in the rms spectra, nor from Anderson–Darling tests of quasars in redshift ranges with and without diffuse nebular emission falling in the observed-frame filters. Contrary to previous work, we do not detect a significant correlation between the measured continuum and BLR lags in our luminous quasar sample, similarly suggesting that our continuum lags are not dominated by diffuse nebular emission. Similar to other studies, we find that quasars with larger-than-expected continuum lags have lower 3000 Å luminosities, and we additionally find longer continuum lags with lower X-ray luminosities and black hole masses. Our lack of evidence for diffuse BLR contribution to the lags indicates that the anticorrelation between continuum lag and luminosity is not likely to be due to the Baldwin effect. Instead, these anticorrelations favor models in which the continuum lag increases in lower-luminosity active galactic nuclei, including scenarios featuring magnetic coupling between the accretion disk and X-ray corona, and/or ripples or rims in the disk.
Published: 2024
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5. A Markedly Expanded Sample of Candidate X-Ray-emitting Isolated Neutron Stars

Author: Sebastian Demasi, Scott F. Anderson, and Marcel A. Agüeros
Subjects: Neutron stars, X-ray surveys, Astrophysics, QB460-466
Abstract: The current sample of 12 radio-quiet isolated neutron stars that emit strongly in X-rays (XINSs) is both small and heterogeneous, limiting its usefulness for understanding the physics of neutron star atmospheres and cooling rates and for constraining the equation of state of neutron degenerate matter. Utilizing the ROSAT 1RXS and 2RXS data sets, in conjunction with the Sloan Digital Sky Survey Data Release 17 and other companion multiwavelength surveys, we have extended previous searches for blank-field X-ray source candidate XINSs, ultimately recovering two known XINSs while identifying 46 new, unstudied candidate fields devoid of likely multiwavelength counterparts. In this publication, we describe our selection approach and provide detailed information regarding our sample of new candidate XINSs. Future opportunities to verify or to refute these X-ray sources as isolated neutron stars by obtaining more accurate X-ray source positions, quality X-ray spectra, or deeper optical imaging are also discussed.
Published: 2024
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6. Erratum: 'Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars' (2019, ApJ, 874, 8)

Author: Chelsea L. MacLeod, Paul J. Green, Scott F. Anderson, Alastair Bruce, Michael Eracleous, Matthew Graham, David Homan, Andy Lawrence, Amy LeBleu, Nicolas P. Ross, John J. Ruan, Jessie Runnoe, Daniel Stern, William Burgett, Kenneth C. Chambers, Nick Kaiser, Eugene Magnier, and Nigel Metcalfe
Subjects: Astrophysics, QB460-466
Published: 2023
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7. The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V

Author: Andrés Almeida, Scott F. Anderson, Maria Argudo-Fernández, Carles Badenes, Kat Barger, Jorge K. Barrera-Ballesteros, Chad F. Bender, Erika Benitez, Felipe Besser, Jonathan C. Bird, Dmitry Bizyaev, Michael R. Blanton, John Bochanski, Jo Bovy, William Nielsen Brandt, Joel R. Brownstein, Johannes Buchner, Esra Bulbul, Joseph N. Burchett, Mariana Cano Díaz, Joleen K. Carlberg, Andrew R. Casey, Vedant Chandra, Brian Cherinka, Cristina Chiappini, Abigail A. Coker, Johan Comparat, Charlie Conroy, Gabriella Contardo, Arlin Cortes, Kevin Covey, Jeffrey D. Crane, Katia Cunha, Collin Dabbieri, James W. Davidson Jr, Megan C. Davis, Anna Barbara de Andrade Queiroz, Nathan De Lee, José Eduardo Méndez Delgado, Sebastian Demasi, Francesco Di Mille, John Donor, Peter Dow, Tom Dwelly, Mike Eracleous, Jamey Eriksen, Xiaohui Fan, Emily Farr, Sara Frederick, Logan Fries, Peter Frinchaboy, Boris T. Gänsicke, Junqiang Ge, Consuelo González Ávila, Katie Grabowski, Catherine Grier, Guillaume Guiglion, Pramod Gupta, Patrick Hall, Keith Hawkins, Christian R. Hayes, J. J. Hermes, Lorena Hernández-García, David W. Hogg, Jon A. Holtzman, Hector Javier Ibarra-Medel, Alexander Ji, Paula Jofre, Jennifer A. Johnson, Amy M. Jones, Karen Kinemuchi, Matthias Kluge, Anton Koekemoer, Juna A. Kollmeier, Marina Kounkel, Dhanesh Krishnarao, Mirko Krumpe, Ivan Lacerna, Paulo Jakson Assuncao Lago, Chervin Laporte, Chao Liu, Ang Liu, Xin Liu, Alexandre Roman Lopes, Matin Macktoobian, Steven R. Majewski, Viktor Malanushenko, Dan Maoz, Thomas Masseron, Karen L. Masters, Gal Matijevic, Aidan McBride, Ilija Medan, Andrea Merloni, Sean Morrison, Natalie Myers, Szabolcs Mészáros, C. Alenka Negrete, David L. Nidever, Christian Nitschelm, Daniel Oravetz, Audrey Oravetz, Kaike Pan, Yingjie Peng, Marc H. Pinsonneault, Rick Pogge, Dan Qiu, Solange V. Ramirez, Hans-Walter Rix, Daniela Fernández Rosso, Jessie Runnoe, Mara Salvato, Sebastian F. Sanchez, Felipe A. Santana, Andrew Saydjari, Conor Sayres, Kevin C. Schlaufman, Donald P. Schneider, Axel Schwope, Javier Serna, Yue Shen, Jennifer Sobeck, Ying-Yi Song, Diogo Souto, Taylor Spoo, Keivan G. Stassun, Matthias Steinmetz, Ilya Straumit, Guy Stringfellow, José Sánchez-Gallego, Manuchehr Taghizadeh-Popp, Jamie Tayar, Ani Thakar, Patricia B. Tissera, Andrew Tkachenko, Hector Hernandez Toledo, Benny Trakhtenbrot, José G. Fernández-Trincado, Nicholas Troup, Jonathan R. Trump, Sarah Tuttle, Natalie Ulloa, Jose Antonio Vazquez-Mata, Pablo Vera Alfaro, Sandro Villanova, Stefanie Wachter, Anne-Marie Weijmans, Adam Wheeler, John Wilson, Leigh Wojno, Julien Wolf, Xiang-Xiang Xue, Jason E. Ybarra, Eleonora Zari, and Gail Zasowski
Subjects: Surveys, Astronomy databases, Astronomy data acquisition, Astronomy software, Astrophysics, QB460-466
Abstract: The eighteenth data release (DR18) of the Sloan Digital Sky Survey (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs or “Mappers”: the Milky Way Mapper (MWM), the Black Hole Mapper (BHM), and the Local Volume Mapper. This data release contains extensive targeting information for the two multiobject spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration and scientifically focused components. DR18 also includes ∼25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.
Published: 2023
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8. Probing the Origin of Changing-look Quasar Transitions with Chandra

Author: Qian Yang, Paul J. Green, Chelsea L. MacLeod, Richard M. Plotkin, Scott F. Anderson, Allyson Bieryla, Francesca Civano, Michael Eracleous, Matthew Graham, John J. Ruan, Jessie Runnoe, and Xiurui Zhao
Subjects: Accretion, Quasars, Active galactic nuclei, Variable radiation sources, Catalogs, Astrophysics, QB460-466
Abstract: Extremely variable quasars can also show strong changes in broad-line emission strength and are known as changing-look quasars (CLQs). To study the CLQ transition mechanism, we present a pilot sample of CLQs with X-ray observations in both the bright and faint states. From a sample of quasars with bright-state archival SDSS spectra and (Chandra or XMM-Newton) X-ray data, we identified five new CLQs via optical spectroscopic follow-up and then obtained new target-of-opportunity X-ray observations with Chandra. No strong absorption is detected in either the bright- or the faint-state X-ray spectra. The intrinsic X-ray flux generally changes along with the optical variability, and the X-ray power-law slope becomes harder in the faint state. Large-amplitude mid-infrared variability is detected in all five CLQs, and it echoes the variability in the optical with a time lag expected from the light-crossing time of the dusty torus for CLQs with robust lag measurements. The changing-obscuration model is not consistent with the observed X-ray spectra and spectral energy distribution changes seen in these CLQs. It is highly likely that the observed changes are due to the changing accretion rate of the supermassive black hole, so the multiwavelength emission varies accordingly, with promising analogies to the accretion states of X-ray binaries.
Published: 2023
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9. Shedding New Light on Weak Emission-line Quasars in the C iv–Hβ Parameter Space

Author: Trung Ha, Cooper Dix, Brandon M. Matthews, Ohad Shemmer, Michael S. Brotherton, Adam D. Myers, Gordon T. Richards, Jaya Maithil, Scott F. Anderson, W. N. Brandt, Aleksandar M. Diamond-Stanic, Xiaohui Fan, S. C. Gallagher, Richard Green, Paulina Lira, Bin Luo, Hagai Netzer, Richard M. Plotkin, Jessie C. Runnoe, Donald P. Schneider, Michael A. Strauss, Benny Trakhtenbrot, and Jianfeng Wu
Subjects: Quasars, Active galactic nuclei, Supermassive black holes, Astrophysics, QB460-466
Abstract: Weak emission-line quasars (WLQs) are a subset of type 1 quasars that exhibit extremely weak Ly α + N v λ 1240 and/or C iv λ 1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 “ordinary” type 1 quasars and 18 WLQs at z < 0.5 and 1.5 < z < 3.5 that have rest-frame ultraviolet and optical spectral measurements. We apply a correction to the H β -based black hole mass ( M _BH ) estimates of these quasars using the strength of the optical Fe ii emission. We confirm previous findings that WLQs’ M _BH values are overestimated by up to an order of magnitude using the traditional broad-emission-line region size–luminosity relation. With this M _BH correction, we find a significant correlation between H β -based Eddington luminosity ratios and a combination of the rest-frame C iv equivalent width and C iv blueshift with respect to the systemic redshift. This correlation holds for both ordinary quasars and WLQs, which suggests that the two-dimensional C iv parameter space can serve as an indicator of accretion rate in all type 1 quasars across a wide range of spectral properties.
Published: 2023
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10. The SDSS-V Black Hole Mapper Reverberation Mapping Project: Unusual Broad-line Variability in a Luminous Quasar

Author: Logan B. Fries, Jonathan R. Trump, Megan C. Davis, C. J. Grier, Yue Shen, Scott F. Anderson, Tom Dwelly, Michael Eracleous, Y. Homayouni, Keith Horne, Mirko Krumpe, Sean Morrison, Jessie C. Runnoe, Benny Trakhtenbrot, Roberto J. Assef, W. N. Brandt, Joel Brownstein, Collin Dabbieri, Alexander Fix, Gloria Fonseca Alvarez, Sara Frederick, P. B. Hall, Anton M. Koekemoer, Jennifer I-Hsiu Li, Xin Liu, Mary Loli Martínez-Aldama, Claudio Ricci, Donald P. Schneider, Hugh W. Sharp, Matthew J. Temple, Qian Yang, Grisha Zeltyn, and Dmitry Bizyaev
Subjects: Active galactic nuclei, Quasars, Supermassive black holes, Astrophysics, QB460-466
Abstract: We present a high-cadence multiepoch analysis of dramatic variability of three broad emission lines (Mg ii , H β , and H α ) in the spectra of the luminous quasar ( λ L _λ (5100 Å) = 4.7 × 10 ^44 erg s ^−1 ) SDSS J141041.25+531849.0 at z = 0.359 with 127 spectroscopic epochs over nine years of monitoring (2013–2022). We observe anticorrelations between the broad emission-line widths and flux in all three emission lines, indicating that all three broad emission lines “breathe” in response to stochastic continuum variations. We also observe dramatic radial velocity shifts in all three broad emission lines, ranging from Δ v ∼ 400 km s ^−1 to ∼800 km s ^−1 , that vary over the course of the monitoring period. Our preferred explanation for the broad-line variability is complex kinematics in the gas in the broad-line region. We suggest a model for the broad-line variability that includes a combination of gas inflow with a radial gradient, an azimuthal asymmetry (e.g., a hot spot), superimposed on the stochastic flux-driven changes to the optimal emission region (“line breathing”). Similar instances of line-profile variability due to complex gas kinematics around quasars are likely to represent an important source of false positives in radial velocity searches for binary black holes, which typically lack the kind of high-cadence data we analyze here. The long-duration, wide-field, and many-epoch spectroscopic monitoring of SDSS-V BHM-RM provides an excellent opportunity for identifying and characterizing broad emission-line variability, and the inferred nature of the inner gas environment, of luminous quasars.
Published: 2023
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11. The Time Domain Spectroscopic Survey: Changing-look Quasar Candidates from Multi-epoch Spectroscopy in SDSS-IV

Author: Paul J. Green, Lina Pulgarin-Duque, Scott F. Anderson, Chelsea L. MacLeod, Michael Eracleous, John J. Ruan, Jessie Runnoe, Matthew Graham, Benjamin R. Roulston, Donald P. Schneider, Austin Ahlf, Dmitry Bizyaev, Joel R. Brownstein, Sonia Joesephine del Casal, Sierra A. Dodd, Daniel Hoover, Cayenne Matt, Andrea Merloni, Kaike Pan, Arnulfo Ramirez, Margaret Ridder, and Serena Moseley
Published: 2022
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12. 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

13. New Clues to the Evolution of Dwarf Carbon Stars From Their Variability and X-ray Emission

Author: Benjamin R. Roulston, Paul J. Green, Rodolfo Montez, Joseph Filippazzo, Jeremy J. Drake, Silvia Toonen, Scott F. Anderson, Michael Eracleous, and Adam Frank
Subjects: Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: As main-sequence stars with C$>$O, dwarf carbon (dC) stars are never born alone but inherit carbon-enriched material from a former asymptotic giant branch (AGB) companion. In contrast to M dwarfs in post-mass transfer binaries, C$_2$ and/or CN molecular bands allow dCs to be identified with modest-resolution optical spectroscopy, even after the AGB remnant has cooled beyond detectability. Accretion of substantial material from the AGB stars should spin up the dCs, potentially causing a rejuvenation of activity detectable in X-rays. Indeed, a few dozen dCs have recently been found to have photometric variability with periods under a day. However, most of those are likely post-common-envelope binaries (PCEBs), spin-orbit locked by tidal forces, rather than solely spun-up by accretion. Here, we study the X-ray properties of a sample of the five nearest known dCs with $Chandra$. Two are detected in X-rays, the only two for which we also detected short-period photometric variability. We suggest that the coronal activity detected so far in dCs is attributable to rapid rotation due to tidal locking in short binary orbits after a common-envelope phase, late in the thermally pulsing (TP) phase of the former C-AGB primary (TP-AGB)., 18 pages, 9 figures, 4 tables, Accepted to ApJ, title changed based on referee recommendation
Published: 2021

14. Probing the disk-corona systems and broad line regions of changing-look quasars with X-ray and optical observations

Author: Anh Doan, Daryl Haggard, Marie Joëlle Gingras, Xiangyu Jin, Paul J. Green, Jessie C. Runnoe, Michael Eracleous, Joseph Hountalas, Chelsea L. MacLeod, Scott F. Anderson, and John J. Ruan
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Active galactic nucleus, 010504 meteorology & atmospheric sciences, Accretion (meteorology), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Type (model theory), Lambda, 01 natural sciences, Corona, Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Emission spectrum, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Line (formation)
Abstract: "Changing-look" quasars are a new class of highly variable active galactic nuclei that have changed their spectral type over surprisingly short timescales of just a few years. The origin of this phenomenon is debated, but is likely to reflect some change in the accretion flow. To investigate the disk-corona systems in these objects, we measure optical/UV-X-ray spectral indices ($\alpha_{\rm OX}$) and Eddington ratios ($\lambda_{\rm Edd}$) of ten previously-discovered changing-look quasars at two or more epochs. By comparing these data with simulated results based on the behavior of X-ray binaries, we find possible similarities in spectral indices below 1% Eddington ratio. We further investigate the Eddington ratios of changing-look quasars before and after their spectral type changes, and find that changing-look quasars cross the 1% Eddington ratio boundary when their broad emission lines disappear/emerge. This is consistent with the disk-wind model as the origin of broad emission lines., Comment: 31 pages, 9 figures, accepted for publication in ApJ
Published: 2021

15. Connecting Low- and High-redshift Weak Emission-line Quasars via Hubble Space Telescope Spectroscopy of Lyα Emission

Author: Jeremiah D. Paul, Richard M. Plotkin, Ohad Shemmer, Scott F. Anderson, W. N. Brandt, Xiaohui Fan, Elena Gallo, Bin Luo, Qingling Ni, Gordon T. Richards, Donald P. Schneider, Jianfeng Wu, and Weimin Yi
Subjects: Space and Planetary Science, Astronomy and Astrophysics
Abstract: We present ultraviolet spectroscopy covering the Lyα + N v complex of six candidate low-redshift (0.9 < z < 1.5) weak emission-line quasars (WLQs) based on observations with the Hubble Space Telescope. The original systematic searches for these puzzling Type 1 quasars with intrinsically weak broad emission lines revealed an N ≈ 100 WLQ population from optical spectroscopy of high-redshift (z > 3) quasars, defined by a Lyα + N v rest-frame equivalent width (EW) threshold z < 3) WLQ candidates, however, has relied primarily on optical spectroscopy of weak broad emission lines at longer rest-frame wavelengths. With these new observations expanding existing optical coverage into the ultraviolet, we explore unifying the low- and high-z WLQ populations via EW[Lyα+N v]. Two objects in the sample unify with high-z WLQs, three others appear consistent with the intermediate portion of the population connecting WLQs and normal quasars, and the final object is consistent with typical quasars. The expanded wavelength coverage improves the number of available line diagnostics for our individual targets, allowing a better understanding of the shapes of their ionizing continua. The ratio of EW[Lyα+N v] to EW[Mg ii] in our sample is generally small but varied, favoring a soft ionizing continuum scenario for WLQs, and we find a lack of correlation between EW[Lyα+N v] and the X-ray properties of our targets, consistent with a “slim-disk” shielding gas model. We also find indications that weak absorption may be a more significant contaminant in low-z WLQ populations than previously thought.
Published: 2022

16. 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), 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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

17. The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release

Author: Joel R. Brownstein, Scott F. Anderson, Nicolás G. Busca, Pauline Zarrouk, Will J. Percival, Johan Comparat, Brad W. Lyke, Patrick Petitjean, Julian E. Bautista, Mara Salvato, Benjamin A. Weaver, Jonathan Brinkmann, Jiamin Hou, Danielle P. Schurhammer, Kyle S. Dawson, Alexandra N. Higley, Alina Streblyanska, Ashley J. Ross, James Rich, Isabelle Pâris, Jeffrey A. Newman, Solène Chabanier, Nathalie Palanque-Delabrouille, W. N. Brandt, Hélion du Mas des Bourboux, Graziano Rossi, Donald P. Schneider, Adam D. Myers, Andrea Muñoz Gutiérrez, Paul J. Green, Alex Smith, Etienne Burtin, J. N. McLane, M. Vivek, Dmitry Bizyaev, Axel de la Macorra, Paul Martini, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), and ANR-16-CE31-0021,eBOSS,Sondes cosmologiques de la gravitation et de l'énergie noire(2016)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Cosmology, Observational cosmology, 0103 physical sciences, ROSAT, Emission spectrum, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common, Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, 13. Climate action, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This catalog comprises the largest selection of spectroscopically confirmed quasars to date. The full catalog includes two sub-catalogs: a "superset" of all SDSS-IV/eBOSS objects targeted as quasars containing 1,440,615 observations and a quasar-only catalog containing 750,414 quasars, including 225,082 new quasars appearing in an SDSS data release for the first time, as well as known quasars from SDSS-I/II/III. We present automated identification and redshift information for these quasars alongside data from visual inspections for 320,161 spectra. The quasar-only catalog is estimated to be 99.8% complete with 0.3% to 1.3% contamination. Automated and visual inspection redshifts are supplemented by redshifts derived via principal component analysis and emission lines. We include emission line redshifts for H$\alpha$, H$\beta$, Mg II, C III], C IV, and Ly$\alpha$. Identification and key characteristics generated by automated algorithms are presented for 99,856 Broad Absorption Line quasars and 35,686 Damped Lyman Alpha quasars. In addition to SDSS photometric data, we also present multi-wavelength data for quasars from GALEX, UKIDSS, WISE, FIRST, ROSAT/2RXS, XMM-Newton, and Gaia. Calibrated digital optical spectra for these quasars can be obtained from the SDSS Science Archive Server., Comment: 32 pages, 13 figures, 6 tables. Accepted to ApJS. Catalog files are available at https://data.sdss.org/sas/dr16/eboss/qso/DR16Q/ . A summary of all SDSS BAO and RSD measurements with legacy figures can be found at https://www.sdss.org/science/final-bao-and-rsd-measurements/ while full cosmological interpretation of these can be found at https://www.sdss.org/science/cosmology-results-from-eboss/
Published: 2020

18. Changing-look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars

Author: Amy Lebleu, Matthew J. Graham, Paul J. Green, Nicholas P. Ross, Daniel Stern, Eugene A. Magnier, Nigel Metcalfe, Jessie C. Runnoe, Nick Kaiser, Alastair Bruce, Chelsea L. MacLeod, John J. Ruan, Andy Lawrence, Michael Eracleous, Scott F. Anderson, K. C. Chambers, William S. Burgett, D. Homan, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Department of Astronomy [Seattle], University of Washington [Seattle], Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Cahill Center for Astronomy and Astrophysics, California Institute of Technology (CALTECH), University of Central Florida [Orlando] (UCF), McGill University = Université McGill [Montréal, Canada], Department of Astronomy, University of Michigan, University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institute for Astronomy, University of Hawai'i at Manoa, Astrophysique, Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7), Smithsonian Institution-Harvard University [Cambridge], University of Central Florida [Orlando], McGill University, Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), and Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Active galactic nucleus, 010504 meteorology & atmospheric sciences, astro-ph.GA, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Photometry (optics), 0103 physical sciences, education, Spectroscopy, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Physics, education.field_of_study, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Galaxy, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA)
Abstract: Active galactic nuclei (AGN) that show strong rest-frame optical/UV variability in their blue continuum and broad line emission are classified as "changing-look" AGN, or at higher luminosities changing look quasars (CLQs). These surprisingly large and sometimes rapid transitions challenge accepted models of quasar physics and duty cycles, offer several new avenues for study of quasar host galaxies, and open a wider interpretation of the cause of differences between broad and narrow line AGN. To better characterize extreme quasar variability, we present follow-up spectroscopy as part of a comprehensive search for CLQs across the full SDSS footprint using spectroscopically confirmed quasars from the SDSS DR7 catalog. Our primary selection requires large-amplitude (|\Delta g|>1 mag, |\Delta r|>0.5 mag) variability over any of the available time baselines probed by the SDSS and Pan-STARRS 1 surveys. We employ photometry from the Catalina Sky Survey to verify variability behavior in CLQ candidates where available, and confirm CLQs using optical spectroscopy from the William Herschel, MMT, Magellan, and Palomar telescopes. For our adopted S/N threshold on variability of broad H\beta emission, we find 17 new CLQs, yielding a confirmation rate of >~ 20%. These candidates are at lower Eddington ratio relative to the overall quasar population which supports a disk-wind model for the broad line region. Based on our sample, the CLQ fraction increases from 10% to roughly half as the continuum flux ratio between repeat spectra at 3420 Angstroms increases from 1.5 to 6. We release a catalog of over 200 highly variable candidates to facilitate future CLQ searches., Comment: 26 pages, 9 Figures, 3 Tables. Replaced with accepted version
Published: 2019

19. The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-Look Quasars

Author: Scott F. Anderson, Daryl Haggard, Michael Eracleous, Chelsea L. MacLeod, Paul J. Green, Jessie C. Runnoe, Malgosia Sobolewska, and John J. Ruan
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Supermassive black hole, Spectral index, Active galactic nucleus, 010504 meteorology & atmospheric sciences, Stellar mass, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Accretion (astrophysics), Black hole, Space and Planetary Science, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract: Despite their factor of ~10^8 difference in black hole mass, several lines of evidence suggest possible similarities between black hole accretion flows in active galactic nuclei (AGN) and Galactic X-ray binaries. However, it is still unclear whether the geometry of the disk-corona system in X-ray binaries directly scale up to AGN, and whether this analogy still holds in different accretion states. We test this AGN/X-ray binary analogy, by comparing the observed correlations between the UV-to-X-ray spectral index (alpha_OX) and Eddington ratio in AGN to those predicted from observations of X-ray binary outbursts. This approach probes the geometry of their disk-corona systems as they transition between different accretion states. We use new Chandra X-ray and ground-based rest-UV observations of faded 'changing-look' quasars to extend this comparison to lower Eddington ratios of, 26 pages, 12 figures, published in ApJ, 883, 76
Published: 2019
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20. LSST: from Science Drivers to Reference Design and Anticipated Data Products

Author: Željko Ivezić, Steven M. Kahn, J. Anthony Tyson, Bob Abel, Emily Acosta, Robyn Allsman, David Alonso, Yusra AlSayyad, Scott F. Anderson, John Andrew, James Roger P. Angel, George Z. Angeli, Reza Ansari, Pierre Antilogus, Constanza Araujo, Robert Armstrong, Kirk T. Arndt, Pierre Astier, Éric Aubourg, Nicole Auza, Tim S. Axelrod, Deborah J. Bard, Jeff D. Barr, Aurelian Barrau, James G. Bartlett, Amanda E. Bauer, Brian J. Bauman, Sylvain Baumont, Ellen Bechtol, Keith Bechtol, Andrew C. Becker, Jacek Becla, Cristina Beldica, Steve Bellavia, Federica B. Bianco, Rahul Biswas, Guillaume Blanc, Jonathan Blazek, Roger D. Blandford, Josh S. Bloom, Joanne Bogart, Tim W. Bond, Michael T. Booth, Anders W. Borgland, Kirk Borne, James F. Bosch, Dominique Boutigny, Craig A. Brackett, Andrew Bradshaw, William Nielsen Brandt, Michael E. Brown, James S. Bullock, Patricia Burchat, David L. Burke, Gianpietro Cagnoli, Daniel Calabrese, Shawn Callahan, Alice L. Callen, Jeffrey L. Carlin, Erin L. Carlson, Srinivasan Chandrasekharan, Glenaver Charles-Emerson, Steve Chesley, Elliott C. Cheu, Hsin-Fang Chiang, James Chiang, Carol Chirino, Derek Chow, David R. Ciardi, Charles F. Claver, Johann Cohen-Tanugi, Joseph J. Cockrum, Rebecca Coles, Andrew J. Connolly, Kem H. Cook, Asantha Cooray, Kevin R. Covey, Chris Cribbs, Wei Cui, Roc Cutri, Philip N. Daly, Scott F. Daniel, Felipe Daruich, Guillaume Daubard, Greg Daues, William Dawson, Francisco Delgado, Alfred Dellapenna, Robert de Peyster, Miguel de Val-Borro, Seth W. Digel, Peter Doherty, Richard Dubois, Gregory P. Dubois-Felsmann, Josef Durech, Frossie Economou, Tim Eifler, Michael Eracleous, Benjamin L. Emmons, Angelo Fausti Neto, Henry Ferguson, Enrique Figueroa, Merlin Fisher-Levine, Warren Focke, Michael D. Foss, James Frank, Michael D. Freemon, Emmanuel Gangler, Eric Gawiser, John C. Geary, Perry Gee, Marla Geha, Charles J. B. Gessner, Robert R. Gibson, D. Kirk Gilmore, Thomas Glanzman, William Glick, Tatiana Goldina, Daniel A. Goldstein, Iain Goodenow, Melissa L. Graham, William J. Gressler, Philippe Gris, Leanne P. Guy, Augustin Guyonnet, Gunther Haller, Ron Harris, Patrick A. Hascall, Justine Haupt, Fabio Hernandez, Sven Herrmann, Edward Hileman, Joshua Hoblitt, John A. Hodgson, Craig Hogan, James D. Howard, Dajun Huang, Michael E. Huffer, Patrick Ingraham, Walter R. Innes, Suzanne H. Jacoby, Bhuvnesh Jain, Fabrice Jammes, James Jee, Tim Jenness, Garrett Jernigan, Darko Jevremović, Kenneth Johns, Anthony S. Johnson, Margaret W. G. Johnson, R. Lynne Jones, Claire Juramy-Gilles, Mario Jurić, Jason S. Kalirai, Nitya J. Kallivayalil, Bryce Kalmbach, Jeffrey P. Kantor, Pierre Karst, Mansi M. Kasliwal, Heather Kelly, Richard Kessler, Veronica Kinnison, David Kirkby, Lloyd Knox, Ivan V. Kotov, Victor L. Krabbendam, K. Simon Krughoff, Petr Kubánek, John Kuczewski, Shri Kulkarni, John Ku, Nadine R. Kurita, Craig S. Lage, Ron Lambert, Travis Lange, J. Brian Langton, Laurent Le Guillou, Deborah Levine, Ming Liang, Kian-Tat Lim, Chris J. Lintott, Kevin E. Long, Margaux Lopez, Paul J. Lotz, Robert H. Lupton, Nate B. Lust, Lauren A. MacArthur, Ashish Mahabal, Rachel Mandelbaum, Thomas W. Markiewicz, Darren S. Marsh, Philip J. Marshall, Stuart Marshall, Morgan May, Robert McKercher, Michelle McQueen, Joshua Meyers, Myriam Migliore, Michelle Miller, David J. Mills, Connor Miraval, Joachim Moeyens, Fred E. Moolekamp, David G. Monet, Marc Moniez, Serge Monkewitz, Christopher Montgomery, Christopher B. Morrison, Fritz Mueller, Gary P. Muller, Freddy Muñoz Arancibia, Douglas R. Neill, Scott P. Newbry, Jean-Yves Nief, Andrei Nomerotski, Martin Nordby, Paul O’Connor, John Oliver, Scot S. Olivier, Knut Olsen, William O’Mullane, Sandra Ortiz, Shawn Osier, Russell E. Owen, Reynald Pain, Paul E. Palecek, John K. Parejko, James B. Parsons, Nathan M. Pease, J. Matt Peterson, John R. Peterson, Donald L. Petravick, M. E. Libby Petrick, Cathy E. Petry, Francesco Pierfederici, Stephen Pietrowicz, Rob Pike, Philip A. Pinto, Raymond Plante, Stephen Plate, Joel P. Plutchak, Paul A. Price, Michael Prouza, Veljko Radeka, Jayadev Rajagopal, Andrew P. Rasmussen, Nicolas Regnault, Kevin A. Reil, David J. Reiss, Michael A. Reuter, Stephen T. Ridgway, Vincent J. Riot, Steve Ritz, Sean Robinson, William Roby, Aaron Roodman, Wayne Rosing, Cecille Roucelle, Matthew R. Rumore, Stefano Russo, Abhijit Saha, Benoit Sassolas, Terry L. Schalk, Pim Schellart, Rafe H. Schindler, Samuel Schmidt, Donald P. Schneider, Michael D. Schneider, William Schoening, German Schumacher, Megan E. Schwamb, Jacques Sebag, Brian Selvy, Glenn H. Sembroski, Lynn G. Seppala, Andrew Serio, Eduardo Serrano, Richard A. Shaw, Ian Shipsey, Jonathan Sick, Nicole Silvestri, Colin T. Slater, J. Allyn Smith, R. Chris Smith, Shahram Sobhani, Christine Soldahl, Lisa Storrie-Lombardi, Edward Stover, Michael A. Strauss, Rachel A. Street, Christopher W. Stubbs, Ian S. Sullivan, Donald Sweeney, John D. Swinbank, Alexander Szalay, Peter Takacs, Stephen A. Tether, Jon J. Thaler, John Gregg Thayer, Sandrine Thomas, Adam J. Thornton, Vaikunth Thukral, Jeffrey Tice, David E. Trilling, Max Turri, Richard Van Berg, Daniel Vanden Berk, Kurt Vetter, Francoise Virieux, Tomislav Vucina, William Wahl, Lucianne Walkowicz, Brian Walsh, Christopher W. Walter, Daniel L. Wang, Shin-Yawn Wang, Michael Warner, Oliver Wiecha, Beth Willman, Scott E. Winters, David Wittman, Sidney C. Wolff, W. Michael Wood-Vasey, Xiuqin Wu, Bo Xin, Peter Yoachim, Hu Zhan, Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire des matériaux avancés (LMA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Centre de Calcul de l'IN2P3 (CC-IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), LSST, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)
Subjects: 010504 meteorology & atmospheric sciences, Astronomy, observational [methods], Field of view, Astrophysics, 7. Clean energy, 01 natural sciences, law.invention, law, size distribution, sagittarius dwarf galaxy, 010303 astronomy & astrophysics, stars: general, media_common, Physics, Reference design, general [stars], gamma-ray bursts, Astrophysics (astro-ph), observations [cosmology], proper motion stars, ia supernovae, astrometry, methods: observational, Astronomical and Space Sciences, Physical Chemistry (incl. Structural), Milky Way, media_common.quotation_subject, Dark matter, FOS: Physical sciences, Large Synoptic Survey Telescope, Astronomy & Astrophysics, milky-way tomography, Primary mirror, Telescope, surveys, astro-ph, 0103 physical sciences, Galaxy: general, general [Galaxy], 0105 earth and related environmental sciences, dark-energy constraints, Organic Chemistry, Astronomy and Astrophysics, Space and Planetary Science, Sky, tidal disruption events, cosmology: observations, digital sky survey, lensing power spectrum, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta, Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overview
Published: 2019

21. X-ray and multi-epoch optical/UV investigations of BAL to non-BAL quasar transformations

Author: Catherine J. Grier, Patrick B. Hall, Adam D. Myers, W. N. Brandt, M. Vivek, N. Filiz Ak, John J. Ruan, Birong Luo, Sameer, P. Rodriguez Hidalgo, Scott F. Anderson, D. P. Schneider, and N. S. Ahmed
Subjects: Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Photon, 010308 nuclear & particles physics, Epoch (astronomy), Astrophysics::High Energy Astrophysical Phenomena, X-ray, FOS: Physical sciences, Spectral density, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Spectral line, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Ionization, 0103 physical sciences, Absorption (logic), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We report on an X-ray and optical/UV study of eight Broad Absorption Line (BAL) to non-BAL transforming quasars at $z\,\approx\,$1.7-2.2 over 0.29-4.95 rest-frame years with at least three spectroscopic epochs for each quasar from the SDSS, BOSS, $Gemini$, and ARC 3.5-m telescopes. New $Chandra$ observations obtained for these objects show their values of $\alpha_{\rm ox}$ and $\Delta{\alpha}_{\rm ox}$, as well as their spectral energy distributions, are consistent with those of non-BAL quasars. Moreover, our targets have X-ray spectral shapes that are, on average, consistent with weakened absorption with an effective power-law photon index of $\Gamma_{\rm eff}\,=\,1.69^{+0.25}_{-0.25}$. The newer $Gemini$ and ARC 3.5-m spectra reveal that the BAL troughs have remained absent since the BOSS observations where the BAL disappearance was discovered. The X-ray and optical/UV results in tandem are consistent with at least the X-ray absorbing material moving out of the line-of-sight, leaving an X-ray unabsorbed non-BAL quasar. The UV absorber might have become more highly ionized (in a shielding-gas scenario) or also moved out of the line-of-sight (in a wind-clumping scenario)., Comment: 14 pages, 5 figures, Accepted for publication in MNRAS
Published: 2018

22. Now you see it, now you don't: the disappearing central engine of the quasar J1011+5442

Author: Jessie C. Runnoe, Scott F. Anderson, Jenny E. Greene, Tom Dwelly, Donald P. Schneider, Stephanie M. LaMassa, Michael Eracleous, Andrea Merloni, Paul J. Green, John J. Ruan, Sabrina Cales, Eric Morganson, Alexandre Roman-Lopes, Yue Shen, and Antonis Georgakakis
Subjects: Physics, 010308 nuclear & particles physics, Space and Planetary Science, 0103 physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Accretion (finance)
Published: 2015

23. Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-Line Quasars

Author: Ohad Shemmer, Xiaohui Fan, Andrea Marlar, Richard M. Plotkin, Gordon T. Richards, B. Luo, Donald P. Schneider, Aleksandar M. Diamond-Stanic, Scott F. Anderson, W. N. Brandt, and Jianfeng Wu
Subjects: Photon, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Luminosity, 0103 physical sciences, Emission spectrum, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Jet (fluid), Line-of-sight, Accretion (meteorology), 010308 nuclear & particles physics, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present XMM-Newton imaging spectroscopy of ten weak emission-line quasars (WLQs) at $0.928\leq z \leq 3.767$, six of which are radio quiet and four which are radio intermediate. The new X-ray data enabled us to measure the power-law photon index, at rest-frame energies $>2$ keV, in each source with relatively high accuracy. These measurements allowed us to confirm previous reports that WLQs have steeper X-ray spectra, suggesting higher accretion rates with respect to 'typical' quasars. A comparison between the photon indices of our radio-quiet WLQs and those of a control sample of 85 sources shows that the first are significantly higher, at the >~$3\sigma$ level. Collectively, the four radio-intermediate WLQs have lower photon indices with respect to the six radio-quiet WLQs, as may be expected if the spectra of the first group are contaminated by X-ray emission from a jet. Therefore, in the absence of significant jet emission along our line of sight, these results are in agreement with the idea that WLQs constitute the extreme high end of the accretion rate distribution in quasars. We detect soft excess emission in our lowest-redshift radio-quiet WLQ, in agreement with previous findings suggesting that the prominence of this feature is associated with a high accretion rate. We have not detected signatures of Compton reflection, Fe K$\alpha$ lines, or strong variability between two X-ray epochs in any of our WLQs, which can be attributed to their relatively high luminosity., Comment: 14 pages (emulateapj), 7 figures. Accepted for publication in ApJ
Published: 2018

24. The Time-Domain Spectroscopic Survey: Radial Velocity Variability in Dwarf Carbon Stars

Author: Benjamin R. Roulston, Keivan G. Stassun, Chelsea L. MacLeod, John J. Ruan, Joel R. Brownstein, Donald P. Schneider, Carles Badenes, Paul J. Green, and Scott F. Anderson
Subjects: Physics, Proper motion, 010504 meteorology & atmospheric sciences, Binary number, White dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Carbon star, Radial velocity, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Main sequence, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract: Dwarf carbon (dC) stars, main sequence stars showing carbon molecular bands, were initially thought to be an oxymoron since only AGB stars dredge carbon into their atmospheres. Mass transfer from a former AGB companion that has since faded to a white dwarf seems the most likely explanation. Indeed, a few types of giants known to show anomalous abundances --- notably, the CH, Ba and CEMP-s stars --- are known to have a high binary frequency. The dC stars may be the enhanced-abundance progenitors of most, if not all, of these systems, but this requires demonstrating a high binary frequency for dCs. Here, for a sample of 240 dC stars targeted for repeat spectroscopy by the SDSS-IV's Time Domain Spectroscopic Survey, we analyze radial velocity variability to constrain the binary frequency and orbital properties. A handful of dC systems show large velocity variability ($>$100 km s$^{-1}$). We compare the dCs to a control sample with a similar distribution of magnitude, color, proper motion, and parallax. Using MCMC methods, we use the measured $\Delta$RV distribution to estimate the binary fraction and the separation distribution assuming both a unimodal and bimodal distribution. We find the dC stars have an enhanced binary fraction of 95\%, consistent with them being products of mass transfer. These models result in mean separations of less than 1 AU corresponding to periods on the order of 1 year. Our results support the conclusion that dC stars form from close binary systems via mass transfer., Comment: 13 pages, 11 figures. Accepted to ApJ April 15, 2019
Published: 2018
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25. The Sloan Digital Sky Survey Quasar Catalog: Fourteenth data release

Author: Anne-Marie Weijmans, Vivek Mariappan, Graziano Rossi, Jean-Paul Kneib, Kyle S. Dawson, Christophe Yèche, Julian E. Bautista, Eric Armengaud, Scott F. Anderson, Rita Tojeiro, Chelsea L. MacLeod, Nathalie Palanque-Delabrouille, Sylvain de la Torre, Michael R. Blanton, Etienne Burtin, Adam D. Myers, Hee-Jong Seo, Joel R. Brownstein, Benjamin A. Weaver, Héctor Gil-Marín, Stephanie M. LaMassa, Ian D. McGreer, W. N. Brandt, Patrick Petitjean, Ashley J. Ross, Jonathan Brinkmann, Will J. Percival, Paul J. Green, Andrea Merloni, Pauline Zarrouk, Patrick B. Hall, Éric Aubourg, Isabelle Pâris, Pasquier Noterdaeme, Jean Marc Le Goff, Brad W. Lyke, Michael Blomqvist, Donald P. Schneider, Antonis Georgakakis, Alina Streblyanska, Gong-Bo Zhao, 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), 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), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Lagrange de Paris, Sorbonne Universités, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), SDSS, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), ANR-16-CE31-0021,eBOSS,Sondes cosmologiques de la gravitation et de l'énergie noire(2016), The Leverhulme Trust, University of St Andrews. School of Physics and Astronomy, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Sorbonne Université (SU), 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), media_common.quotation_subject, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, 01 natural sciences, Cosmology, Spectral line, Photometry (optics), surveys, quasars: general, 0103 physical sciences, QB Astronomy, Emission spectrum, Spectral resolution, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, media_common, QB, Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, general [Quasars], DAS, Astrophysics - Astrophysics of Galaxies, Redshift, QC Physics, 13. Climate action, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), Catalogs, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], catalogs, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present the Data Release 14 Quasar catalog (DR14Q) from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV). This catalog includes all SDSS-IV/eBOSS objects that were spectroscopically targeted as quasar candidates and that are confirmed as quasars via a new automated procedure combined with a partial visual inspection of spectra, have luminosities $M_{\rm i} \left[ z=2 \right] < -20.5$ (in a $\Lambda$CDM cosmology with $H_0 = 70 \ {\rm km \ s^{-1} \ Mpc ^{-1}}$, $\Omega_{\rm M} = 0.3$, and $\Omega_{\rm \Lambda} = 0.7$), and either display at least one emission line with a full width at half maximum (FWHM) larger than $500 \ {\rm km \ s^{-1}}$ or, if not, have interesting/complex absorption features. The catalog also includes previously spectroscopically-confirmed quasars from SDSS-I, II and III. The catalog contains 526,356 quasars 144,046 are new discoveries since the beginning of SDSS-IV) detected over 9,376 deg$^2$ (2,044 deg$^2$ having new spectroscopic data available) with robust identification and redshift measured by a combination of principal component eigenspectra. The catalog is estimated to have about 0.5% contamination. The catalog identifies 21,877 broad absorption line quasars and lists their characteristics. For each object, the catalog presents SDSS five-band CCD-based photometry with typical accuracy of 0.03 mag. The catalog also contains X-ray, ultraviolet, near-infrared, and radio emission properties of the quasars, when available, from other large-area surveys., Comment: Accepted for publication in A&A. The catalog is available at https://data.sdss.org/sas/dr14/eboss/qso/DR14Q/DR14Q_v4_4.fits
Published: 2018

26. The Time-Domain Spectroscopic Survey: Target Selection for Repeat Spectroscopy

Author: John J. Ruan, W. N. Brandt, Nurten Filiz Ak, Kyle S. Dawson, Suzanne L. Hawley, Michael R. Blanton, Jessie C. Runnoe, Sarah J. Schmidt, Amy Lebleu, Chelsea L. MacLeod, Eugene A. Magnier, Jeremy L. Tinker, Daniel Hoover, Michael Eracleous, Jenny E. Greene, Keivan G. Stassun, Rachael Amaro, C. Z. Waters, Eric Morganson, K. C. Chambers, R. P. Kudritzki, José G. Fernández-Trincado, Matthew A. Bershady, Sean McGraw, Nigel Metcalfe, Carles Badenes, Adam D. Myers, Hee-Jong Seo, Axel Schwope, Scott F. Anderson, Vivek Mariappan, Yue Shen, Catherine J. Grier, Isabelle Pâris, Patrick B. Hall, Donald P. Schneider, Paul J. Green, Nick Kaiser, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules ( UTINAM ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), 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), and Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, RR Lyrae variable, 01 natural sciences, surveys, quasars: general, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, Supermassive black hole, 010308 nuclear & particles physics, White dwarf, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Carbon star, stars: variables: general, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Variable star, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: As astronomers increasingly exploit the information available in the time domain, spectroscopic variability in particular opens broad new channels of investigation. Here we describe the selection algorithms for all targets intended for repeat spectroscopy in the Time Domain Spectroscopic Survey (TDSS), part of the extended Baryon Oscillation Spectroscopic Survey within the Sloan Digital Sky Survey-IV. Also discussed are the scientific rationale and technical constraints leading to these target selections. The TDSS includes a large "Repeat Quasar Spectroscopy" (RQS) program delivering ~13,000 repeat spectra of confirmed SDSS quasars, and several smaller "Few-Epoch Spectroscopy" (FES) programs targeting specific classes of quasars as well as stars. The RQS program aims to provide a large and diverse quasar data set for studying variations in quasar spectra on timescales of years, a comparison sample for the FES quasar programs, and opportunity for discovering rare, serendipitous events. The FES programs cover a wide variety of phenomena in both quasars and stars. Quasar FES programs target broad absorption line quasars, high signal-to-noise ratio normal broad line quasars, quasars with double-peaked or very asymmetric broad emission line profiles, binary supermassive black hole candidates, and the most photometrically variable quasars. Strongly variable stars are also targeted for repeat spectroscopy, encompassing many types of eclipsing binary systems, and classical pulsators like RR Lyrae. Other stellar FES programs allow spectroscopic variability studies of active ultracool dwarf stars, dwarf carbon stars, and white dwarf/M dwarf spectroscopic binaries. We present example TDSS spectra and describe anticipated sample sizes and results., 26 pages, 11 figures, replaced with accepted version to AJ
Published: 2017

27. Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

Author: Michael R. Blanton, Matthew A. Bershady, Bela Abolfathi, Franco D. Albareti, Carlos Allende Prieto, Andres Almeida, Javier Alonso-García, Friedrich Anders, Scott F. Anderson, Brett Andrews, Erik Aquino-Ortíz, Alfonso Aragón-Salamanca, Maria Argudo-Fernández, Eric Armengaud, Eric Aubourg, Vladimir Avila-Reese, Carles Badenes, Stephen Bailey, Kathleen A. Barger, Jorge Barrera-Ballesteros, Curtis Bartosz, Dominic Bates, Falk Baumgarten, Julian Bautista, Rachael Beaton, Timothy C. Beers, Francesco Belfiore, Chad F. Bender, Andreas A. Berlind, Mariangela Bernardi, Florian Beutler, Jonathan C. Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael Blomqvist, Adam S. Bolton, Médéric Boquien, Jura Borissova, Remco van den Bosch, Jo Bovy, William N. Brandt, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Adam J. Burgasser, Etienne Burtin, Nicolás G. Busca, Michele Cappellari, Maria Leticia Delgado Carigi, Joleen K. Carlberg, Aurelio Carnero Rosell, Ricardo Carrera, Nancy J. Chanover, Brian Cherinka, Edmond Cheung, Yilen Gómez Maqueo Chew, Cristina Chiappini, Peter Doohyun Choi, Drew Chojnowski, Chia-Hsun Chuang, Haeun Chung, Rafael Fernando Cirolini, Nicolas Clerc, Roger E. Cohen, Johan Comparat, Luiz da Costa, Marie-Claude Cousinou, Kevin Covey, Jeffrey D. Crane, Rupert A. C. Croft, Irene Cruz-Gonzalez, Daniel Garrido Cuadra, Katia Cunha, Guillermo J. Damke, Jeremy Darling, Roger Davies, Kyle Dawson, Axel de la Macorra, Flavia Dell’Agli, Nathan De Lee, Timothée Delubac, Francesco Di Mille, Aleks Diamond-Stanic, Mariana Cano-Díaz, John Donor, Juan José Downes, Niv Drory, Hélion du Mas des Bourboux, Christopher J. Duckworth, Tom Dwelly, Jamie Dyer, Garrett Ebelke, Arthur D. Eigenbrot, Daniel J. Eisenstein, Eric Emsellem, Mike Eracleous, Stephanie Escoffier, Michael L. Evans, Xiaohui Fan, Emma Fernández-Alvar, J. G. Fernandez-Trincado, Diane K. Feuillet, Alexis Finoguenov, Scott W. Fleming, Andreu Font-Ribera, Alexander Fredrickson, Gordon Freischlad, Peter M. Frinchaboy, Carla E. Fuentes, Lluís Galbany, R. Garcia-Dias, D. A. García-Hernández, Patrick Gaulme, Doug Geisler, Joseph D. Gelfand, Héctor Gil-Marín, Bruce A. Gillespie, Daniel Goddard, Violeta Gonzalez-Perez, Kathleen Grabowski, Paul J. Green, Catherine J. Grier, James E. Gunn, Hong Guo, Julien Guy, Alex Hagen, ChangHoon Hahn, Matthew Hall, Paul Harding, Sten Hasselquist, Suzanne L. Hawley, Fred Hearty, Jonay I. Gonzalez Hernández, Shirley Ho, David W. Hogg, Kelly Holley-Bockelmann, Jon A. Holtzman, Parker H. Holzer, Joseph Huehnerhoff, Timothy A. Hutchinson, Ho Seong Hwang, Héctor J. Ibarra-Medel, Gabriele da Silva Ilha, Inese I. Ivans, KeShawn Ivory, Kelly Jackson, Trey W. Jensen, Jennifer A. Johnson, Amy Jones, Henrik Jönsson, Eric Jullo, Vikrant Kamble, Karen Kinemuchi, David Kirkby, Francisco-Shu Kitaura, Mark Klaene, Gillian R. Knapp, Jean-Paul Kneib, Juna A. Kollmeier, Ivan Lacerna, Richard R. Lane, Dustin Lang, David R. Law, Daniel Lazarz, Youngbae Lee, Jean-Marc Le Goff, Fu-Heng Liang, Cheng Li, Hongyu Li, Jianhui Lian, Marcos Lima, Lihwai Lin, Yen-Ting Lin, Sara Bertran de Lis, Chao Liu, Miguel Angel C. de Icaza Lizaola, Dan Long, Sara Lucatello, Britt Lundgren, Nicholas K. MacDonald, Alice Deconto Machado, Chelsea L. MacLeod, Suvrath Mahadevan, Marcio Antonio Geimba Maia, Roberto Maiolino, Steven R. Majewski, Elena Malanushenko, Viktor Malanushenko, Arturo Manchado, Shude Mao, Claudia Maraston, Rui Marques-Chaves, Thomas Masseron, Karen L. Masters, Cameron K. McBride, Richard M. McDermid, Brianne McGrath, Ian D. McGreer, Nicolás Medina Peña, Matthew Melendez, Andrea Merloni, Michael R. Merrifield, Szabolcs Meszaros, Andres Meza, Ivan Minchev, Dante Minniti, Takamitsu Miyaji, Surhud More, John Mulchaey, Francisco Müller-Sánchez, Demitri Muna, Ricardo R. Munoz, Adam D. Myers, Preethi Nair, Kirpal Nandra, Janaina Correa do Nascimento, Alenka Negrete, Melissa Ness, Jeffrey A. Newman, Robert C. Nichol, David L. Nidever, Christian Nitschelm, Pierros Ntelis, Julia E. O’Connell, Ryan J. Oelkers, Audrey Oravetz, Daniel Oravetz, Zach Pace, Nelson Padilla, Nathalie Palanque-Delabrouille, Pedro Alonso Palicio, Kaike Pan, John K. Parejko, Taniya Parikh, Isabelle Pâris, Changbom Park, Alim Y. Patten, Sebastien Peirani, Marcos Pellejero-Ibanez, Samantha Penny, Will J. Percival, Ismael Perez-Fournon, Patrick Petitjean, Matthew M. Pieri, Marc Pinsonneault, Alice Pisani, Radosław Poleski, Francisco Prada, Abhishek Prakash, Anna Bárbara de Andrade Queiroz, M. Jordan Raddick, Anand Raichoor, Sandro Barboza Rembold, Hannah Richstein, Rogemar A. Riffel, Rogério Riffel, Hans-Walter Rix, Annie C. Robin, Constance M. Rockosi, Sergio Rodríguez-Torres, A. Roman-Lopes, Carlos Román-Zúñiga, Margarita Rosado, Ashley J. Ross, Graziano Rossi, John Ruan, Rossana Ruggeri, Eli S. Rykoff, Salvador Salazar-Albornoz, Mara Salvato, Ariel G. Sánchez, D. S. Aguado, José R. Sánchez-Gallego, Felipe A. Santana, Basílio Xavier Santiago, Conor Sayres, Ricardo P. Schiavon, Jaderson da Silva Schimoia, Edward F. Schlafly, David J. Schlegel, Donald P. Schneider, Mathias Schultheis, William J. Schuster, Axel Schwope, Hee-Jong Seo, Zhengyi Shao, Shiyin Shen, Matthew Shetrone, Michael Shull, Joshua D. Simon, Danielle Skinner, M. F. Skrutskie, Anže Slosar, Verne V. Smith, Jennifer S. Sobeck, Flavia Sobreira, Garrett Somers, Diogo Souto, David V. Stark, Keivan Stassun, Fritz Stauffer, Matthias Steinmetz, Thaisa Storchi-Bergmann, Alina Streblyanska, Guy S. Stringfellow, Genaro Suárez, Jing Sun, Nao Suzuki, Laszlo Szigeti, Manuchehr Taghizadeh-Popp, Baitian Tang, Charling Tao, Jamie Tayar, Mita Tembe, Johanna Teske, Aniruddha R. Thakar, Daniel Thomas, Benjamin A. Thompson, Jeremy L. Tinker, Patricia Tissera, Rita Tojeiro, Hector Hernandez Toledo, Sylvain de la Torre, Christy Tremonti, Nicholas W. Troup, Octavio Valenzuela, Inma Martinez Valpuesta, Jaime Vargas-González, Mariana Vargas-Magaña, Jose Alberto Vazquez, Sandro Villanova, M. Vivek, Nicole Vogt, David Wake, Rene Walterbos, Yuting Wang, Benjamin Alan Weaver, Anne-Marie Weijmans, David H. Weinberg, Kyle B. Westfall, David G. Whelan, Vivienne Wild, John Wilson, W. M. Wood-Vasey, Dominika Wylezalek, Ting Xiao, Renbin Yan, Meng Yang, Jason E. Ybarra, Christophe Yèche, Nadia Zakamska, Olga Zamora, Pauline Zarrouk, Gail Zasowski, Kai Zhang, Gong-Bo Zhao, Zheng Zheng, Xu Zhou, Zhi-Min Zhou, Guangtun B. Zhu, Manuela Zoccali, Hu Zou, The Leverhulme Trust, University of St Andrews. School of Physics and Astronomy, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, APC - Cosmologie, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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), 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), 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), 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), 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), 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), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), 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, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), 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), 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), 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), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)
Subjects: Astrophysics and Astronomy, Milky Way, astro-ph.GA, FOS: Physical sciences, Espectros astronômicos, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, 01 natural sciences, law.invention, Telescope, Redshift-space distortions, surveys, Observatory, law, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, spectrographs [Instrumentation], observations [Cosmology], Galaxy: general, stars: general, 010303 astronomy & astrophysics, general [Galaxy], QC, Astrophysics::Galaxy Astrophysics, instrumentation: spectrographs, QB, Mapeamentos astronômicos, Physics, general [Stars], 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, general [Galaxies], DAS, galaxies: general, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, QC Physics, Space and Planetary Science, cosmology: observations, Astrophysics of Galaxies (astro-ph.GA), Catalogos astronomicos, Baryon acoustic oscillations, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratio in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially-resolved spectroscopy for thousands of nearby galaxies (median redshift of z = 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between redshifts z = 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGN and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5-meter Sloan Foundation Telescope at Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5-meter du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in July 2016., Published in Astronomical Journal
Published: 2017

28. SPIDERS: Selection of spectroscopic targets using AGN candidates detected in all-sky X-ray surveys

Author: Scott F. Anderson, D. Coffey, Chichuan Jin, Johannes Buchner, Tom Dwelly, A. Del Moro, Axel Schwope, M. L. Menzel, Paul J. Green, Nicolas Clerc, Antonis Georgakakis, Th. Boller, Andrea Merloni, Marcella Brusa, W. N. Brandt, J. Ridl, Robert C. Nichol, T. Simm, Kirpal Nandra, Tamás Budavári, Mara Salvato, Adam D. Myers, Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), 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), Dwelly, T., Salvato, M., Merloni, A., Brusa, M., Buchner, J., Anderson, S. F., Boller, T. h., Brandt, W. N., Budavári, T., Clerc, N., Coffey, D., Del Moro, A., Georgakakis, A., Green, P. J., Jin, C., Menzel, M. -. L., Myers, A. D., Nandra, K., Nichol, R. C., Ridl, J., Schwope, A. D., and Simm, T.
Subjects: media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], galaxies: active, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Cosmology, surveys, quasars: general, 0103 physical sciences, ROSAT, Cluster analysis, 010303 astronomy & astrophysics, Galaxy cluster, Selection (genetic algorithm), Astrophysics::Galaxy Astrophysics, media_common, surveys, galaxies: active, quasars: general, galaxies: Seyfert, cosmology: observations, X-rays: galaxies, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Redshift, galaxies: Seyfert, X-rays: galaxies, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), cosmology: observations, Magnitude (astronomy), Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: SPIDERS (SPectroscopic IDentification of eROSITA Sources) is an SDSS-IV survey running in parallel to the eBOSS cosmology project. SPIDERS will obtain optical spectroscopy for large numbers of X-ray-selected AGN and galaxy cluster members detected in wide area eROSITA, XMM-Newton and ROSAT surveys. We describe the methods used to choose spectroscopic targets for two sub-programmes of SPIDERS: X-ray selected AGN candidates detected in the ROSAT All Sky and the XMM-Newton Slew surveys. We have exploited a Bayesian cross-matching algorithm, guided by priors based on mid-IR colour-magnitude information from the WISE survey, to select the most probable optical counterpart to each X-ray detection. We empirically demonstrate the high fidelity of our counterpart selection method using a reference sample of bright well-localised X-ray sources collated from XMM-Newton, Chandra and Swift-XRT serendipitous catalogues, and also by examining blank-sky locations. We describe the down-selection steps which resulted in the final set of SPIDERS-AGN targets put forward for spectroscopy within the eBOSS/TDSS/SPIDERS survey, and present catalogues of these targets. We also present catalogues of ~12000 ROSAT and ~1500 XMM-Newton Slew survey sources which have existing optical spectroscopy from SDSS-DR12, including the results of our visual inspections. On completion of the SPIDERS program, we expect to have collected homogeneous spectroscopic redshift information over a footprint of ~7500 deg$^2$ for >85 percent of the ROSAT and XMM-Newton Slew survey sources having optical counterparts in the magnitude range 17, Comment: MNRAS, accepted
Published: 2017

29. X-ray Insights into the Nature of Quasars with Redshifted Broad Absorption Lines

Author: W. N. Brandt, Patrick Petitjean, Scott F. Anderson, N. Filiz Ak, Yue Shen, N. S. Ahmed, B. Luo, Patrick B. Hall, Raghunathan Srianand, Donald P. Schneider, Ning Xiao Zhang, Institut d'Astrophysique de Paris ( IAP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Photon, 010504 meteorology & atmospheric sciences, Absorption spectroscopy, Astrophysics::High Energy Astrophysical Phenomena, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, accretion, quasars: general, 0103 physical sciences, Absorption (logic), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Degree (graph theory), accretion disks, Spectral density, Astronomy and Astrophysics, Quasar, Redshift, quasars: absorption lines, X-rays: galaxies, Space and Planetary Science, galaxies: nuclei, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We present $Chandra$ observations of seven broad absorption line (BAL) quasars at $z=0.863$-2.516 with redshifted BAL troughs (RSBALs). Five of our seven targets were detected by $Chandra$ in 4-13 ks exposures with ACIS-S. The $\alpha_{\rm ox}$ values, $\Delta\alpha_{\rm ox}$ values, and spectral energy distributions of our targets demonstrate they are all X-ray weak relative to expectations for non-BAL quasars, and the degree of X-ray weakness is consistent with that of appropriately-matched BAL quasars generally. Furthermore, our five detected targets show evidence for hard X-ray spectral shapes with a stacked effective power-law photon index of $\Gamma_{\rm eff}=0.5^{+0.5}_{-0.4}$. These findings support the presence of heavy X-ray absorption ($N_{\rm H}\approx 2 \times 10^{23}$ cm$^{-2}$) in RSBAL quasars, likely by the shielding gas found to be common in BAL quasars more generally. We use these X-ray measurements to assess models for the nature of RSBAL quasars, finding that a rotationally-dominated outflow model is favored while an infall model also remains plausible with some stipulations. The X-ray data disfavor a binary quasar model for RSBAL quasars in general., Comment: 11 pages, 5 figures, and 3 tables
Published: 2017

30. Broad Absorption Line Disappearance And Emergence Using Multiple-Epoch Spectroscopy From The Sloan Digital Sky Survey

Author: Timothy A. Hutchinson, Scott F. Anderson, Catherine J. Grier, W. N. Brandt, Patrick B. Hall, Paul J. Green, Chelsea L. MacLeod, M. Vivek, N. Filiz Ak, Donald P. Schneider, and Sean McGraw
Subjects: Physics, 010308 nuclear & particles physics, Epoch (reference date), media_common.quotation_subject, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, respiratory system, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Spectral line, respiratory tract diseases, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Outflow, Spectroscopy, 010303 astronomy & astrophysics, media_common
Abstract: We investigate broad absorption line (BAL) disappearance and emergence using a 470 BAL-quasar sample over < 0.10-5.25 rest-frame years with at least three spectroscopic epochs for each quasar from the Sloan Digital Sky Survey. We identify 14 disappearing BALs over < 1.73-4.62 rest-frame years and 18 emerging BALs over < 1.46-3.66 rest-frame years associated with the CIV 1548,1550 and/or SiIV 1393,1402 doublets, and report on their variability behavior. BAL quasars in our dataset exhibit disappearing/emerging CIV BALs at a rate of 2.3 and 3.0 per cent, respectively, and the frequency for BAL to non-BAL quasar transitions is 1.7 per cent. We detect four re-emerging BALs over < 3.88 rest-frame years on average and three re-disappearing BALs over < 4.15 rest-frame years on average, the first reported cases of these types. We infer BAL lifetimes along the line of sight to be nominally < 100-1000 yr using disappearing CIV BALs in our sample. Interpretations of (re-)emerging and (re-)disappearing BALs reveal evidence that collectively supports both transverse-motion and ionization-change scenarios to explain BAL variations. We constrain a nominal CIV/SiIV BAL outflow location of < 100 pc from the central source and a radial size of > 1x10^-7 pc (0.02 au) using the ionization-change scenario, and constrain a nominal outflow location of < 0.5 pc and a transverse size of ~0.01 pc using the transverse-motion scenario. Our findings are consistent with previous work, and provide evidence in support of BALs tracing compact flow geometries with small filling factors., 25 pages, 9 figures, 5 tables, accepted to MNRAS, please visit MNRAS or contact W.N. Brandt to access supplementary material
Published: 2017

31. Spectral evolution in high redshift quasars from the final Baryon Oscillation Spectroscopic Survey sample

Author: Isabelle Pâris, Kyle S. Dawson, Julian E. Bautista, David W. Harris, Ian D. McGreer, Kaike Pan, Paul J. Green, Donald P. Schneider, Trey W. Jensen, Nao Suzuki, Vikrant Kamble, Joel R. Brownstein, Scott F. Anderson, W. N. Brandt, Andrea Merloni, M. Vivek, Adam D. Myers, Daniel Oravetz, Dmitry Bizyaev, and Audrey Simmons
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Population, black hole physics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, surveys, emission lines [quasars], 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Malmquist bias, Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, Spectral index, general [quasars], 010308 nuclear & particles physics, Quasar, Astronomy and Astrophysics, Redshift, Black hole, Space and Planetary Science, active [galaxies], Equivalent width
Abstract: We report on the diversity in quasar spectra from the Baryon Oscillation Spectroscopic Survey. After filtering the spectra to mitigate selection effects and Malmquist bias associated with a nearly flux-limited sample, we create high signal-to-noise ratio composite spectra from 58,656 quasars (2.1 ≤ z ≤ 3.5), binned by luminosity, spectral index, and redshift. With these composite spectra, we confirm the traditional Baldwin effect (BE, i.e., the anticorrelation of C IV equivalent width (EW) and luminosity) that follows the relation Wλ ∝ Lβw with slope βw = -0.35 ± 0.004, -0.35 ± 0.005, and -0.41 ± 0.005 for z = 2.25, 2.46, and 2.84, respectively. In addition to the redshift evolution in the slope of the BE, we find redshift evolution in average quasar spectral features at fixed luminosity. The spectroscopic signature of the redshift evolution is correlated at 98% with the signature of varying luminosity, indicating that they arise from the same physical mechanism. At a fixed luminosity, the average C IV FWHM decreases with increasing redshift and is anti-correlated with C IV EW. The spectroscopic signature associated with C IV FWHM suggests that the trends in luminosity and redshift are likely caused by a superposition of effects that are related to black hole mass and Eddington ratio. The redshift evolution is the consequence of a changing balance between these two quantities as quasars evolve toward a population with lower typical accretion rates at a given black hole mass.
Published: 2016

32. A Chandra Study: Are Dwarf Carbon Stars Spun Up and Rejuvenated by Mass Transfer?

Author: Rodolfo Montez, Paul J. Green, Jeremy J. Drake, Orsola De Marco, Joseph C. Filippazzo, Jay Farihi, Fernando Mazzoni, Benjamin R. Roulston, Joel H. Kastner, Adam Frank, Scott F. Anderson, and Brent Miszalski
Subjects: Physics, Angular momentum, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, White dwarf, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Dredge-up, Planetary nebula, Accretion (astrophysics), Carbon star, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Dynamo
Abstract: Carbon stars (with C/O> 1) were long assumed to all be giants, because only AGB stars dredge up significant carbon into their atmospheres. The case is nearly iron-clad now that the formerly mysterious dwarf carbon (dC) stars are actually far more common than C giants, and have accreted carbon-rich material from a former AGB companion, yielding a white dwarf and a dC star that has gained both significant mass and angular momentum. Some such dC systems have undergone a planetary nebula phase, and some may evolve to become CH, CEMP, or Ba giants. Recent studies indicate that most dCs are likely from older, metal-poor kinematic populations. Given the well-known anti-correlation of age and activity, dCs would not be expected to show significant X-ray emission related to coronal activity. However, accretion spin-up might be expected to rejuvenate magnetic dynamos in these post mass-transfer binary systems. We describe our Chandra pilot study of six dCs selected from the SDSS for Halpha emission and/or a hot white dwarf companion, to test whether their X-ray emission strength and spectral properties are consistent with a rejuvenated dynamo. We detect all 6 dCs in the sample, which have X-ray luminosities ranging from logLx= 28.5 - 29.7, preliminary evidence that dCs may be active at a level consistent with stars that have short rotation periods of several days or less. More definitive results require a sample of typical dCs with deeper X-ray observations to better constrain their plasma temperatures., 13 pages, 5 figures. Revised and resubmitted June 20, accepted June 21, 2019 to ApJ
Published: 2019

33. Gemini Imaging of the Host Galaxies of Changing-look Quasars

Author: John J. Ruan, Scott F. Anderson, Daryl Haggard, Chelsea L. MacLeod, Jessie C. Runnoe, Paul J. L. Charlton, and Michael Eracleous
Subjects: Active galactic nucleus, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Doubly ionized oxygen, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy merger, 01 natural sciences, Luminosity, 0103 physical sciences, Surface brightness, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Sersic profile
Abstract: Changing-look quasars are a newly-discovered class of luminous active galactic nuclei that undergo rapid ($\lesssim$10 year) transitions between Type 1 and Type 1.9/2, with an associated change in their continuum emission. We characterize the host galaxies of four faded changing-look quasars using broadband optical imaging. We use \textit{gri} images obtained with the Gemini Multi Object Spectrograph (GMOS) on Gemini North to characterize the surface brightness profiles of the quasar hosts and search for [O III] $\lambda4959,\lambda5007$ emission from spatially extended regions, or voorwerpjes, with the goal of using them to examine past luminosity history. Although we do not detect, voorwerpjes surrounding the four quasar host galaxies, we take advantage of the dim nuclear emission to characterize the colors and morphologies of the host galaxies. Three of the four galaxies show morphological evidence of merger activity or tidal features in their residuals. The three galaxies which are not highly distorted are fit with a single S\'ersic profile to characterize their overall surface brightness profiles. The single-S\'ersic fits give intermediate S\'ersic indices between the $n=1$ of disk galaxies and the $n=4$ of ellipticals. On a color-magnitude diagram, our changing-look quasar host galaxies reside in the blue cloud, with other AGN host galaxies and star-forming galaxies. On a color-S\'ersic index diagram the changing-look quasar hosts reside with other AGN hosts in the "green valley". Our analysis suggests that the hosts of changing-look quasars are predominantly disrupted or merging galaxies that resemble AGN hosts, rather than inactive galaxies., Comment: 20 pages, 5 figures
Published: 2019

34. Performance of the CLEO IIILiF-TEA ring imaging Cherenkov detector in a high-energy muon beam

Author: Igor Volobouev, Jingbo Ye, R. Mountain, G. Viehhauser, T. E. Coan, R. Ayad, Yuichi Kubota, Scott F. Anderson, V. Fadeyev, S. Schuh, Sacha E Kopp, Sheldon Stone, Gobinda Majumder, E. Lipeles, Tomasz Skwarnicki, Marina Artuso, A. Efimov, F. Azfar, A. J.S. Smith, and J. C. Wang
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Muon, Physics::Instrumentation and Detectors, Detector, FOS: Physical sciences, Ring-imaging Cherenkov detector, law.invention, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), law, Angular resolution, High Energy Physics::Experiment, Fermilab, Beam dump, Instrumentation, Cherenkov radiation
Abstract: The CLEO III Ring Imaging Cherenkov detector uses LiF radiators to generate Cherenkov photons which are then detected by proportional wire chambers using a mixture of CH$_4$ and TEA gases. The first two photon detector modules which were constructed, were taken to Fermilab and tested in a beam dump that provided high momentum muons. We report on results using both plane and "sawtooth" shaped radiators. Specifically, we discuss the number of photoelectrons observed per ring and the angular resolution. The particle separation ability is shown to be sufficient for the physics of CLEO III., To be published in Nuclear Instruments and Methods A
Published: 2016

35. The time-domain spectroscopic survey: Understanding the optically variable sky with sequels in SDSS-III

Author: Matthew A. Bershady, Donald P. Schneider, Chelsea L. MacLeod, W. N. Brandt, Jean-Paul Kneib, Kyle S. Dawson, Timothy M. Heckman, Jedidah Isler, Nicholas P. Ross, Scott F. Anderson, Carles Badenes, Donald G. York, Keivan G. Stassun, James R. A. Davenport, H. Flewelling, Paula Szkody, Edward F. Schlafly, Jessie C. Runnoe, Eric Morganson, Michael Eracleous, Isabelle Paris, Yue Shen, John J. Ruan, C. Z. Waters, Adam D. Myers, K. C. Chambers, Axel Schwope, Paul J. Green, Nick Kaiser, Sarah J. Schmidt, Department of Astrophysical Sciences [Princeton], Princeton University, Department of Physics and Astronomy [UCLA Los Angeles], University of California [Los Angeles] (UCLA), University of California-University of California, Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), Laboratoire d'Astrophysique de Marseille (LAM), 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), Universidad de Chile = University of Chile [Santiago] (UCHILE), University of California (UC)-University of California (UC), 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: Cosmology and Nongalactic Astrophysics (astro-ph.CO), astro-ph.SR, media_common.quotation_subject, astro-ph.GA, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, RR Lyrae variable, Astronomy & Astrophysics, 01 natural sciences, Atomic, Physical Chemistry, Spectral line, Particle and Plasma Physics, surveys, quasars: general, 0103 physical sciences, Binary star, Astrophysics::Solar and Stellar Astrophysics, Nuclear, Time domain, Blazar, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, media_common, Physics, general [quasars], 010308 nuclear & particles physics, Molecular, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Redshift, stars: variables: general, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Sky, variables: general [stars], Astrophysics of Galaxies (astro-ph.GA), astro-ph.CO, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astronomical and Space Sciences, Astrophysics - Cosmology and Nongalactic Astrophysics, Physical Chemistry (incl. Structural)
Abstract: The Time-Domain Spectroscopic Survey (TDSS) is an SDSS-IV eBOSS subproject primarily aimed at obtaining identification spectra of ~220,000 optically-variable objects systematically selected from SDSS/Pan-STARRS1 multi-epoch imaging. We present a preview of the science enabled by TDSS, based on TDSS spectra taken over ~320 deg^2 of sky as part of the SEQUELS survey in SDSS-III, which is in part a pilot survey for eBOSS in SDSS-IV. Using the 15,746 TDSS-selected single-epoch spectra of photometrically variable objects in SEQUELS, we determine the demographics of our variability-selected sample, and investigate the unique spectral characteristics inherent in samples selected by variability. We show that variability-based selection of quasars complements color-based selection by selecting additional redder quasars, and mitigates redshift biases to produce a smooth quasar redshift distribution over a wide range of redshifts. The resulting quasar sample contains systematically higher fractions of blazars and broad absorption line quasars than from color-selected samples. Similarly, we show that M-dwarfs in the TDSS-selected stellar sample have systematically higher chromospheric active fractions than the underlying M-dwarf population, based on their H-alpha emission. TDSS also contains a large number of RR Lyrae and eclipsing binary stars with main-sequence colors, including a few composite-spectrum binaries. Finally, our visual inspection of TDSS spectra uncovers a significant number of peculiar spectra, and we highlight a few cases of these interesting objects. With a factor of ~15 more spectra, the main TDSS survey in SDSS-IV will leverage the lessons learned from these early results for a variety of time-domain science applications., 17 pages, 14 figures, submitted to ApJ
Published: 2016

36. CIV BROAD ABSORPTION LINE ACCELERATION IN SLOAN DIGITAL SKY SURVEY QUASARS

Author: W. N. Brandt, Alexandre Roman-Lopes, Patrick B. Hall, Thomas G. Beatty, Mouyuan Sun, Catherine J. Grier, Jonathan R. Trump, Scott F. Anderson, Joel R. Brownstein, M. Vivek, N. Filiz Ak, Donald P. Schneider, and Paul J. Green
Subjects: media_common.quotation_subject, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Acceleration, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common, Physics, Line-of-sight, 010308 nuclear & particles physics, Astronomy and Astrophysics, Quasar, respiratory system, Astrophysics - Astrophysics of Galaxies, Galaxy, respiratory tract diseases, Black hole, 13. Climate action, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), Magnitude (astronomy)
Abstract: We present results from the largest systematic investigation of broad absorption line (BAL) acceleration to date. We use spectra of 140 quasars from three Sloan Digital Sky Survey programs to search for global velocity offsets in BALs over timescales of ~2.5-5.5 years in the quasar rest frame. We carefully select acceleration candidates by requiring monolithic velocity shifts over the entire BAL trough, avoiding BALs with velocity shifts that might be caused by profile variability. The CIV BALs of two quasars show velocity shifts consistent with the expected signatures of BAL acceleration, and the BAL of one quasar shows a velocity-shift signature of deceleration. In our two acceleration candidates, we see evidence that the magnitude of the acceleration is not constant over time; the magnitudes of the change in acceleration for both acceleration candidates are difficult to produce with a standard disk-wind model or via geometric projection effects. We measure upper limits to acceleration and deceleration for 76 additional BAL troughs and find that the majority of BALs are stable to within about 3% of their mean velocities. The lack of widespread acceleration/deceleration could indicate that the gas producing most BALs is located at large radii from the central black hole and/or is not currently strongly interacting with ambient material within the host galaxy along our line of sight., Accepted for publication in ApJ. 25 pages (13 Figures, 4 Tables)
Published: 2016

37. The SDSS-IV Extended Baryon Oscillation Spectroscopic Survey : overview and early data

Author: Joe Huehnerhoff, Jo Bovy, Jean-Marc Le Goff, Nicolás G. Busca, Matthew A. Bershady, Will J. Percival, Yipeng Jing, Marcio A. G. Maia, Conor Sayres, Diana Holder, Xiaohui Fan, Eric Jullo, Flavia Sobreira, Sergio Rodríguez-Torres, Vikrant Kamble, Antonio D. Montero-Dorta, Yu Liang, Andreas A. Berlind, Patrick Gaulme, Beth Reid, Stephen Bailey, Peter Nugent, Andrea Merloni, Peter M. Frinchaboy, Dmitry Bizyaev, A. C. Rosell, Gong-Bo Zhao, Tracy Naugle, Yen-Ting Lin, Vivek Mariappan, Zhongxu Zhai, Julien Guy, Hélion du Mas des Bourboux, Shirley Ho, Martin White, Éric Aubourg, Abhishek Prakash, Pasquier Noterdaeme, Yuting Wang, Audrey Oravetz, Dustin Lang, Uroš Seljak, W. N. Brandt, Demitri Muna, Patrick Petitjean, Sylvain de la Torre, M. C. Cousinou, Ian D. McGreer, Pierre Laurent, Adam D. Myers, Isabelle Paris, Andres Meza, John J. Ruan, Franco D. Albareti, Etienne Burtin, Kyle S. Dawson, Adam S. Bolton, Alina Streblyanska, Nikhil Padmanabhan, Marcos Lima, Chia-Hsun Chuang, Kaike Pan, Benjamin A. Weaver, Daniel J. Eisenstein, Branimir Sesar, Mariana Vargas-Magaña, Ashley J. Ross, Alice Pisani, Axel de la Macorra, Mark A. Klaene, Nathalie Palanque-Delabrouille, Karen Kinemuchi, Nicholas R. MacDonald, Rita Tojeiro, Nicolas Clerc, Nao Suzuki, Scott F. Anderson, Dan Long, John A. Peacock, Kirpal Nandra, Johan Comparat, D. Kirkby, Anze Slosar, Timothy A. Hutchinson, Michael Blomqvist, Donald P. Schneider, Stephanie Escoffier, Jeremy L. Tinker, Charling Tao, Irene Cruz-González, Jon Brinkmann, Michael Eracleous, Francisco-Shu Kitaura, Hu Zou, Elena Malanushenko, Yiping Shu, Anand Raichoor, W. M. Wood-Vasey, Andreu Font-Ribera, Tom Dwelly, J. Ridl, Graziano Rossi, Hee-Jong Seo, Britt Lundgren, Sarah Shandera, Brice Ménard, Luiz N. da Costa, Shadab Alam, Ricardo L. C. Ogando, Christophe Yèche, Daniel Oravetz, Matthew M. Pieri, Jean-Paul Kneib, Julian E. Bautista, Weipeng Lin, Mara Salvato, Antonis Georgakakis, Alexis Finoguenov, Hong Guo, Florian Beutler, Guangtun Zhu, Jeremy Darling, Zheng Zheng, Frances Cope, Donna Taylor, Francisco Prada, David H. Weinberg, Cheng Li, Rupert A. C. Croft, Joel R. Brownstein, Viktor Malanushenko, Paul J. Green, Jeffrey A. Newman, John K. Parejko, David J. Schlegel, Matthew D. Olmstead, Russ R. Laher, Cameron K. McBride, Cheng Zhao, Timothée Delubac, James Rich, Michael R. Blanton, Eric Armengaud, Anne Ealet, Zheng Cai, Qiufan Lin, University of St Andrews. School of Physics and Astronomy, AVL, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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), Department of Astronomy and Astrophysics [PennState], Pennsylvania State University (Penn State), Penn State System-Penn State System, Departamento de FisicaTeorica e IFT-UAM/CSIC, Universidad Autónoma de Madrid (UAM), 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), EPFL Laboratoire d’astrophysique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, 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, Research Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), McMaster University [Hamilton, Ontario], 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), Department of Physics and Astronomy [Irvine], University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), Département de Physique des Particules (ex SPP) (DPhP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Shanghai Astronomical Observatory [Shanghai] (SHAO), Chinese Academy of Sciences [Beijing] (CAS), Departamento de Fisica Matematica, Universidade de São Paulo = University of São Paulo (USP), Max-Planck-Institut für Astrophysik (MPA), Department of Physics and Astronomy [Pittsburgh], University of Pittsburgh (PITT), Pennsylvania Commonwealth System of Higher Education (PCSHE)-Pennsylvania Commonwealth System of Higher Education (PCSHE), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Universidad de Chile = University of Chile [Santiago] (UCHILE), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), APC - Cosmologie, 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)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Department of Electrical and Computer Engineering [Minneapolis] (ECE), University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, China National Research Center of Intelligent Equipment for Agriculture [Beijing] (NRCIEA), Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Shandong University, Laboratoire de Chimie - UMR5182 (LC), 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Universidad Autonoma de Madrid (UAM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Laboratoire d'Astrophysique, Ecole Polytechnique Fédérale de Lausanne (EPFL), 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), 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), University of California [Irvine] (UCI), University of California-University of California, Département de Physique des Particules (ex SPP) (DPP), Universidade de São Paulo (USP), Universidad Santiago de Chile, PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, University of Minnesota [Twin Cities], École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), UAM. Departamento de Física Teórica, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, 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), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Cosmology and Gravitation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, 01 natural sciences, surveys, Tests of general relativity, 0103 physical sciences, ST/K0090X/1, QB Astronomy, Emission spectrum, observations [Cosmology], 010303 astronomy & astrophysics, STFC, Astrophysics::Galaxy Astrophysics, QC, QB, Physics, 010308 nuclear & particles physics, Física, RCUK, Astronomy and Astrophysics, Quasar, 3rd-DAS, Redshift, Galaxy, Baryon, QC Physics, Space and Planetary Science, cosmology: observations, astro-ph.CO, Baryon acoustic oscillations, Neutrino, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The Astrophysical Journal 151.2 (2016): 44 reproduced by permission of the AAS, In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneously with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. In particular, eBOSS will measure with percent-level precision the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. eBOSS will use four different tracers of the underlying matter density field to vastly expand the volume covered by BOSS and map the large-scale-structures over the relatively unconstrained redshift range 0.6 < z < 2.2. Using more than 250,000 new, spectroscopically confirmed luminous red galaxies at a median redshift z = 0.72, we project that eBOSS will yield measurements of the angular diameter distance dA(z) to an accuracy of 1.2% and measurements of H(z) to 2.1% when combined with the z > 0.6 sample of BOSS galaxies. With ∼195,000 new emission line galaxy redshifts, we expect BAO measurements of dA(z) to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z = 0.87. A sample of more than 500,000 spectroscopically confirmed quasars will provide the first BAO distance measurements over the redshift range 0.9 < z < 2.2, with expected precision of 2.8% and 4.2% on dA(z) and H(z), respectively. Finally, with 60,000 new quasars and re-observation of 60,000 BOSS quasars, we will obtain new Lyα forest measurements at redshifts z > 2.1; these new data will enhance the precision of dA(z) and H(z) at z > 2.1 by a factor of 1.44 relative to BOSS. Furthermore, eBOSS will provide improved tests of General Relativity on cosmological scales through redshift-space distortion measurements, improved tests for non-Gaussianity in the primordial density field, and new constraints on the summed mass of all neutrino species. Here, we provide an overview of the cosmological goals, spectroscopic target sample, demonstration of spectral quality from early data, and projected cosmological constraints from eBOSS, K.D. acknowledges support from the U.S. Department of Energy under Grant DE-SC000995. J.P.K. and T.D. acknowledge support from the ERC advanced grant LIDA. W.J.P. acknowledges support from the UK STFC through the consolidated grant ST/K0090X/1, and from the European Research Council through grant Darksurvey
Published: 2016

38. Using the Fundamental Plane of black hole activity to distinguish X-ray processes from weakly accreting black holes

Author: Richard M. Plotkin, Scott F. Anderson, Sera Markoff, Elmar Koerding, and Brandon C. Kelly
Subjects: Physics, Accretion (meteorology), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Synchrotron radiation, Sigma, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Luminosity, Black hole, General Relativity and Quantum Cosmology, Space and Planetary Science, 0103 physical sciences, Radiative transfer, Fundamental plane (elliptical galaxies), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The fundamental plane of black hole activity is a relation between X-ray luminosity, radio luminosity, and black hole mass for hard state Galactic black holes and their supermassive analogs. The fundamental plane suggests that, at low-accretion rates, the physical processes regulating the conversion of an accretion flow into radiative energy could be universal across the entire black hole mass scale. However, there is still a need to further refine the fundamental plane in order to better discern the radiative processes and their geometry very close to the black hole, in particular the source of hard X-rays. Further refinement is necessary because error bars on the best-fit slopes of the fundamental plane are generally large, and also the inferred coefficients can be sensitive to the adopted sample of black holes. In this work, we regress the fundamental plane with a Bayesian technique. Our approach shows that sub-Eddington black holes emit X-ray emission that is predominantly optically thin synchrotron radiation from the jet, provided that their radio spectra are flat or inverted. X-ray emission dominated by very radiatively inefficient accretion flows are excluded at the >3\sigma\ level. We also show that it is difficult to place FR I galaxies onto the fundamental plane because their X-ray jet emission is highly affected by synchrotron cooling. On the other hand, BL Lac objects fit onto the fundamental plane. Including a uniform subset of high-energy peaked BL Lac objects from the SDSS, we find sub-Eddington black holes with flat/inverted radio spectra follow log L_x=(1.45\pm0.04)log L_R-(0.88\pm0.06)\logM_{BH}-6.07\pm1.10, with \sigma_{int}=0.07\pm0.05 dex. Finally, we discuss how the effects of synchrotron cooling of jet emission from the highest black hole masses can bias fundamental plane regressions, perhaps leading to incorrect inferences on X-ray radiation mechanisms.
Published: 2011

39. Dynamical black hole masses of BL Lac objects from the Sloan Digital Sky Survey

Author: Richard M. Plotkin, Scott F. Anderson, Sera Markoff, and Scott Trager
Subjects: Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Cosmic distance ladder, Velocity dispersion, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Redshift, Luminosity, Black hole, General Relativity and Quantum Cosmology, Space and Planetary Science, Bulge, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, BL Lac object
Abstract: We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey with redshifts out to z~0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black hole mass - stellar velocity dispersion relation. We find BL Lac objects host black holes of similar masses, ~10^{8.5} M_sun, with a dispersion of 0.4 dex, similar to the uncertainties on each black hole measurement. Therefore, all BL Lac objects in our sample have the same indistinguishable black hole mass. These 71 BL Lac objects follow the black hole mass - bulge luminosity relation, and their narrow range of host galaxy luminosities confirm previous claims that BL Lac host galaxies can be treated as standard candles. We conclude that the observed diversity in the shapes of BL Lac object spectral energy distributions is not strongly driven by black hole mass or host galaxy properties.
Published: 2011

40. X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3

Author: Scott F. Anderson, Albert K. H. Kong, Shih Hao Lan, Walter H. G. Lewin, Cees Bassa, Frank Verbunt, and David Pooley
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Astrophysics::High Energy Astrophysical Phenomena, X-ray, FOS: Physical sciences, Binary number, Astronomy and Astrophysics, Astrophysics, Radius, Core (optical fiber), Collision frequency, Space and Planetary Science, Observatory, Hubble space telescope, Globular cluster, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on the Chandra X-ray Observatory and Hubble Space Telescope observation of two low core density globular clusters, NGC6144 and E3. By comparing the number of X-ray sources inside the half-mass radius to those outside, we found 6 X-ray sources within the half-mass radius of NGC6144, among which 4 are expected to be background sources; 3 X-ray sources are also found within the half-mass radius of E3, of which 3 is expected to be background source. Therefore, we cannot exclude that all our sources are background sources. However, combining the results from X-ray and optical observations, we found that 1-2 sources in NGC6144 and 1 source in E3 are likely to be cataclysmic variables and that 1 source in NGC6144 is an active binary, based on the X-ray and optical properties. The number of faint X-ray sources in NGC6144 and E3 found with Chandra and HST is higher than a prediction based on collision frequency, but is closer to that based on mass. Our observations strongly suggest that the compact binary systems in NGC6144 and E3 are primordial in origin., Comment: 28 pages, 9 figures, 6 tables, Accepted for publication in ApJ
Published: 2010

41. Multiwavelength observations of radio-quiet quasars with weak emission lines

Author: W. N. Brandt, Xiaohui Fan, Donald P. Schneider, Chelsea L. MacLeod, Aleksandar M. Diamond-Stanic, Richard M. Plotkin, Scott F. Anderson, Ohad Shemmer, and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Active galactic nucleus, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Flux, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Light curve, Galaxy, Stars, Space and Planetary Science, Sky, Emission spectrum, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, media_common
Abstract: We present radio and X-ray observations, as well as optical light curves, for a subset of 26 BL Lac candidates from the Sloan Digital Sky Survey (SDSS) lacking strong radio emission and with z, 15 pages, 4 figures, 5 tables. Accepted for publication in ApJ
Published: 2010

42. Optically selected BL Lacertae candidates from the Sloan Digital Sky Survey Data Release Seven

Author: Amy Kimball, Daniel Oravetz, Scott F. Anderson, Michael Richmond, Xiaohui Fan, Ohad Shemmer, Patrick B. Hall, A. Simmonds, Donald P. Schneider, W. Voges, N. A. Bahcall, K. Pan, A. M. Diamond-Stanic, S. A. Snedden, D. G. York, Howard Brewington, Dmitry Bizyaev, W. N. Brandt, E. Malanushenko, V. Malanushenko, Richard M. Plotkin, and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, education.field_of_study, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Population, FOS: Physical sciences, White dwarf, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Redshift, Space and Planetary Science, Sky, ROSAT, Astrophysics - High Energy Astrophysical Phenomena, education, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, media_common
Abstract: We present a sample of 723 optically selected BL Lac candidates from the SDSS DR7 spectroscopic database encompassing 8250 deg^2 of sky; our sample constitutes one of the largest uniform BL Lac samples yet derived. Each BL Lac candidate has a high-quality SDSS spectrum from which we determine spectroscopic redshifts for ~60% of the objects. Redshift lower limits are estimated for the remaining objects utilizing the lack of host galaxy flux contamination in their optical spectra; we find that objects lacking spectroscopic redshifts are likely at systematically higher redshifts. Approximately 80% of our BL Lac candidates match to a radio source in FIRST/NVSS, and ~40% match to a ROSAT X-ray source. The homogeneous multiwavelength coverage allows subdivision of the sample into 637 radio-loud BL Lac candidates and 86 weak-featured radio-quiet objects. The radio-loud objects broadly support the standard paradigm unifying BL Lac objects with beamed radio galaxies. We propose that the majority of the radio-quiet objects may be lower-redshift (z, 24 pages, 14 figures, 8 tables. Accepted for publication in AJ
Published: 2010

43. PROBING THE BALANCE OF AGN AND STAR-FORMING ACTIVITY IN THE LOCAL UNIVERSE WITH ChaMP

Author: Paul J. Green, Wayne A. Barkhouse, Daryl Haggard, Scott F. Anderson, Dong-Woo Kim, Anca Constantin, and Tom Aldcroft
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Supermassive black hole, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Stellar mass, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Accretion (astrophysics), Galaxy, Redshift, Luminosity, Black hole, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The combination of the SDSS and the Chandra Multiwavelength Project (ChaMP) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relation between X-ray nuclear emission, nebular line-emission, black hole masses, and properties of the associated stellar populations. We present here novel constraints that both X-ray luminosity Lx and X-ray spectral energy distribution bring to the galaxy evolutionary sequence H II -> Seyfert/Transition Object -> LINER -> Passive suggested by optical data. In particular, we show that both Lx and Gamma, the slope of the power-law that best fits the 0.5 - 8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z ~ 0, or at low luminosity AGN levels, there is an anti-correlation between Gamma and L/Ledd, opposite to the trend exhibited by high z AGN (quasars). The turning point in the Gamma -L/Ledd LLAGN + quasars relation occurs near Gamma ~ 1.5 and L/Ledd ~ 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anti-correlation we find between Gamma and L/Ledd may instead indicate that stronger accretion correlates with greater absorption. Therefore the trend for softer spectra toward more luminous, high redshift, and strongly accreting AGN/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections., 23 pages, 8 figures, 1 long (3 page) table, to appear in ApJ
Published: 2009

44. TEN MORE NEW SIGHTLINES FOR THE STUDY OF INTERGALACTIC HELIUM, AND HUNDREDS OF FAR-ULTRAVIOLET-BRIGHT QUASARS, FROM THE SLOAN DIGITAL SKY SURVEY, GALAXY EVOLUTION EXPLORER , AND HUBBLE SPACE TELESCOPE

Author: David Syphers, Daryl Haggard, Avery Meiksin, Donald G. York, Donald P. Schneider, Scott F. Anderson, and Wei Zheng
Subjects: Physics, QSOS, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, chemistry.chemical_element, Astronomy and Astrophysics, Small sample, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Redshift, chemistry, Space and Planetary Science, Intergalactic medium, Astrophysics::Solar and Stellar Astrophysics, Intergalactic travel, Reionization, Astrophysics::Galaxy Astrophysics, Helium
Abstract: Absorption along quasar sightlines remains among the most sensitive direct measures of HeII reionization in much of the intergalactic medium (IGM). Until recently, fewer than a half-dozen unobscured quasar sightlines suitable for the HeII Gunn-Peterson test were known; although these handful demonstrated great promise, the small sample size limited confidence in cosmological inferences. We have recently added nine more such clean HeII quasars, exploiting SDSS quasar samples, broadband UV imaging from GALEX, and high-yield UV spectroscopic confirmations from HST. Here we markedly expand this approach by cross-correlating SDSS DR7 and GALEX GR4+5 to catalog 428 SDSS and 165 other quasars with z>2.78 having likely (~70%) GALEX detections, suggesting they are bright into the far-UV. Reconnaissance HST Cycle 16 Supplemental prism data for 29 of these new quasar-GALEX matches spectroscopically confirm 17 as indeed far-UV bright. At least 10 of these confirmations have clean sightlines all the way down to HeII Lyman-alpha, substantially expanding the number of known clean HeII quasars, and reaffirming the order of magnitude enhanced efficiency of our selection technique. Combined confirmations from this and our past programs yield more than twenty HeII quasars, quintupling the sample. These provide substantial progress toward a sample of HeII quasar sightlines large enough, and spanning a sufficient redshift range, to enable statistical IGM studies that may avoid individual object peculiarity and sightline variance. Our expanded catalog of hundreds of high-likelihood far-UV-bright QSOs additionally will be useful for understanding the extreme-UV properties of the quasars themselves.
Published: 2009

45. NO NEUTRON STAR COMPANION TO THE LOWEST MASS SDSS WHITE DWARF

Author: Nicole M. Silvestri, Mukremin Kilic, Scott F. Anderson, Marcel A. Agüeros, Fernando Camilo, Paulo C. C. Freire, James Liebert, S. J. Kleinman, and Craig O. Heinke
Subjects: Physics, 010308 nuclear & particles physics, Green Bank Telescope, FOS: Physical sciences, White dwarf, Astronomy and Astrophysics, Astrophysics, Compact star, Surface gravity, 01 natural sciences, Neutron star, Astrophysics - Solar and Stellar Astrophysics, Pulsar, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: SDSS J091709.55+463821.8 (hereafter J0917+4638) is the lowest surface gravity white dwarf (WD) currently known, with log g = 5.55 +/- 0.05 (M ~ 0.17 M_sun; Kilic et al. 2007a,b). Such low-mass white dwarfs (LMWDs) are believed to originate in binaries that evolve into WD/WD or WD/neutron star (NS) systems. An optical search for J0917+4638's companion showed that it must be a compact object with a mass >= 0.28 M_sun (Kilic 2007b). Here we report on Green Bank Telescope 820 MHz and XMM-Newton X-ray observations of J0917+4638 intended to uncover a potential NS companion to the LMWD. No convincing pulsar signal is detected in our radio data. Our X-ray observation also failed to detect X-ray emission from J0917+4638's companion, while we would have detected any of the millisecond radio pulsars in 47 Tuc. We conclude that the companion is almost certainly another WD., 4 pages, 1 table; to appear in the Astrophysical Journal Letters
Published: 2009

46. THE SEVENTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY

Author: Kevork N. Abazajian, Jennifer K. Adelman-McCarthy, Marcel A. Agüeros, Sahar S. Allam, Carlos Allende Prieto, Deokkeun An, Kurt S. J. Anderson, Scott F. Anderson, James Annis, Neta A. Bahcall, C. A. L. Bailer-Jones, J. C. Barentine, Bruce A. Bassett, Andrew C. Becker, Timothy C. Beers, Eric F. Bell, Vasily Belokurov, Andreas A. Berlind, Eileen F. Berman, Mariangela Bernardi, Steven J. Bickerton, Dmitry Bizyaev, John P. Blakeslee, Michael R. Blanton, John J. Bochanski, William N. Boroski, Howard J. Brewington, Jarle Brinchmann, J. Brinkmann, Robert J. Brunner, Tamás Budavári, Larry N. Carey, Samuel Carliles, Michael A. Carr, Francisco J. Castander, David Cinabro, A. J. Connolly, István Csabai, Carlos E. Cunha, Paul C. Czarapata, James R. A. Davenport, Ernst de Haas, Ben Dilday, Mamoru Doi, Daniel J. Eisenstein, Michael L. Evans, N. W. Evans, Xiaohui Fan, Scott D. Friedman, Joshua A. Frieman, Masataka Fukugita, Boris T. Gänsicke, Evalyn Gates, Bruce Gillespie, G. Gilmore, Belinda Gonzalez, Carlos F. Gonzalez, Eva K. Grebel, James E. Gunn, Zsuzsanna Györy, Patrick B. Hall, Paul Harding, Frederick H. Harris, Michael Harvanek, Suzanne L. Hawley, Jeffrey J. E. Hayes, Timothy M. Heckman, John S. Hendry, Gregory S. Hennessy, Robert B. Hindsley, J. Hoblitt, Craig J. Hogan, David W. Hogg, Jon A. Holtzman, Joseph B. Hyde, Shin-ichi Ichikawa, Takashi Ichikawa, Myungshin Im, Željko Ivezić, Sebastian Jester, Linhua Jiang, Jennifer A. Johnson, Anders M. Jorgensen, Mario Jurić, Stephen M. Kent, R. Kessler, S. J. Kleinman, G. R. Knapp, Kohki Konishi, Richard G. Kron, Jurek Krzesinski, Nikolay Kuropatkin, Hubert Lampeitl, Svetlana Lebedeva, Myung Gyoon Lee, Young Sun Lee, R. French Leger, Sébastien Lépine, Nolan Li, Marcos Lima, Huan Lin, Daniel C. Long, Craig P. Loomis, Jon Loveday, Robert H. Lupton, Eugene Magnier, Olena Malanushenko, Viktor Malanushenko, Rachel Mandelbaum, Bruce Margon, John P. Marriner, David Martínez-Delgado, Takahiko Matsubara, Peregrine M. McGehee, Timothy A. McKay, Avery Meiksin, Heather L. Morrison, Fergal Mullally, Jeffrey A. Munn, Tara Murphy, Thomas Nash, Ada Nebot, Eric H. Neilsen, Heidi Jo Newberg, Peter R. Newman, Robert C. Nichol, Tom Nicinski, Maria Nieto-Santisteban, Atsuko Nitta, Sadanori Okamura, Daniel J. Oravetz, Jeremiah P. Ostriker, Russell Owen, Nikhil Padmanabhan, Kaike Pan, Changbom Park, George Pauls, John Peoples, Will J. Percival, Jeffrey R. Pier, Adrian C. Pope, Dimitri Pourbaix, Paul A. Price, Norbert Purger, Thomas Quinn, M. Jordan Raddick, Paola Re Fiorentin, Gordon T. Richards, Michael W. Richmond, Adam G. Riess, Hans-Walter Rix, Constance M. Rockosi, Masao Sako, David J. Schlegel, Donald P. Schneider, Ralf-Dieter Scholz, Matthias R. Schreiber, Axel D. Schwope, Uroš Seljak, Branimir Sesar, Erin Sheldon, Kazu Shimasaku, Valena C. Sibley, A. E. Simmons, Thirupathi Sivarani, J. Allyn Smith, Martin C. Smith, Vernesa Smolčić, Stephanie A. Snedden, Albert Stebbins, Matthias Steinmetz, Chris Stoughton, Michael A. Strauss, Mark SubbaRao, Yasushi Suto, Alexander S. Szalay, István Szapudi, Paula Szkody, Masayuki Tanaka, Max Tegmark, Luis F. A. Teodoro, Aniruddha R. Thakar, Christy A. Tremonti, Douglas L. Tucker, Alan Uomoto, Daniel E. Vanden Berk, Jan Vandenberg, S. Vidrih, Michael S. Vogeley, Wolfgang Voges, Nicole P. Vogt, Yogesh Wadadekar, Shannon Watters, David H. Weinberg, Andrew A. West, Simon D. M. White, Brian C. Wilhite, Alainna C. Wonders, Brian Yanny, D. R. Yocum, Donald G. York, Idit Zehavi, Stefano Zibetti, and Daniel B. Zucker
Subjects: Cosmology and Gravitation, Astronomy, media_common.quotation_subject, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, atlases, catalogs, surveys, law.invention, Photometry (optics), law, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics, media_common, Physics, Imaging systems in astronomy, Stars--Observations, Celestial equator, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, Astrometry, Astrograph, Galaxy, Stars, Space and Planetary Science, Sky
Abstract: This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged), Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor corrections
Published: 2009

47. A HIGH YIELD OF NEW SIGHTLINES FOR THE STUDY OF INTERGALACTIC HELIUM: FAR-UV-BRIGHT QUASARS FROM THE SDSS,GALEX, ANDHST

Author: Avery Meiksin, Kuenley Chiu, Daryl Haggard, Wei Zheng, Craig J. Hogan, D. G. York, Scott F. Anderson, Donald P. Schneider, and David Syphers
Subjects: Physics, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Flux, chemistry.chemical_element, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Cosmic variance, Spectral line, Redshift, chemistry, Space and Planetary Science, Intergalactic travel, Reionization, Astrophysics::Galaxy Astrophysics, Helium
Abstract: Investigations of He II Ly-alpha (304 A rest) absorption toward a half-dozen quasars at z~3-4 have demonstrated the great potential of helium studies of the IGM, but the current critically small sample size of clean sightlines for the He II Gunn-Peterson test limits confidence in cosmological inferences, and a larger sample is required. Although the unobscured quasar sightlines to high redshift are extremely rare, SDSS DR6 provides thousands of z>2.8 quasars. We have cross-correlated these SDSS quasars with GALEX GR2/GR3 to establish a catalog of 200 higher-confidence (~70% secure) cases of quasars at z=2.8-5.1 potentially having surviving far-UV (restframe) flux. We also catalog another 112 likely far-UV-bright quasars from GALEX cross-correlation with other (non-SDSS) quasar compilations. Reconnaissance UV prism observations with HST of 24 of our SDSS/GALEX candidates confirm 12 as detected in the far-UV, with at least 9 having flux extending to very near the He II break; with refinements our success rate is even higher. Our SDSS/GALEX selection approach is thereby confirmed to be an order of magnitude more efficient than previous He II quasar searches, more than doubles the number of spectroscopically confirmed clean sightlines to high redshift, and provides a resource list of hundreds of high-confidence sightlines for upcoming He II and other far-UV studies from HST. Our reconnaissance HST prism spectra suggest some far-UV diversity, confirming the need to obtain a large sample of independent quasar sightlines across a broad redshift range to assess such issues as the epoch(s) of helium reionization, while averaging over individual-object pathology and/or cosmic variance., 32 pages, 7 figures, accepted by ApJ
Published: 2008

48. Intergalactic He<scp>ii</scp>Absorption in the Spectra of Quasars at Redshifts 3.5 and 3.8, Observed with theHSTACS Prism

Author: David H. Weinberg, Scott F. Anderson, Wei Zheng, Avery Meiksin, Gerard A. Kriss, Donald P. Schneider, Kuenley Chiu, Donald G. York, Eric R. Tittley, Keith Pifko, and Craig J. Hogan
Subjects: Physics, Absorption spectroscopy, Astronomy, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Advanced Camera for Surveys, Spectral line, Redshift, Absorption edge, Space and Planetary Science, Intergalactic travel, Emission spectrum, Astrophysics::Galaxy Astrophysics
Abstract: We present the UV spectra of two quasars obtained with the Hubble Space Telescope Advanced Camera for Surveys (HST ACS) prism (R ~ 100). One quasar, at redshift z = 3.5, shows an absorption edge consistent either with nearly fully ionized helium with an intergalactic He II Lyα optical depth at 304 A of τ304 > 3.1 (90% confidence), or a He III region with edge 5.4 Mpc from the QSO. The spectrum of the second quasar, at z = 3.8, has a broad absorption profile extending across the He II emission line of the quasar consistent with a damped absorption profile from an intervening He II system at z 3.7 with a column density of approximately 1022 cm−2. In this case, the extremely high He II column density and absence of strong H I absorption suggests that the radiation field is quite weak at 4 ryd. The combined He II and H I signatures are consistent with photoionization by a compact (1-100 pc) star-forming region located approximately 10 Mpc from the quasar.
Published: 2008

49. The Milky Way Tomography with SDSS. II. Stellar Metallicity

Author: Julianne J. Dalcanton, Brian C. Lee, Masataka Fukugita, Furea Kiuchi, James Bushong, Jeffrey A. Munn, Suzanne L. Hawley, Young Sun Lee, Thomas R. Quinn, James E. Gunn, Mike Harvanek, Robert H. Lupton, Alexander Chen, Alan Uomoto, R. Wilhelm, Constance M. Rockosi, Mamoru Doi, Jeffrey R. Pier, Brian Yanny, David J. Schlegel, J. C. Barentine, S. J. Kleinman, Branimir Sesar, Carlos Allende Prieto, Paola Re Fiorentin, Gajus Miknaitis, Atsuko Nitta, Jurek Krzesinski, Heidi Jo Newberg, Stephanie A. Snedden, Hugh C. Harris, Nicholas A. Bond, Scott F. Anderson, Donald P. Schneider, Douglas P. Finkbeiner, J. Allyn Smith, Coryn A. L. Bailer-Jones, Dan Long, Thirupathi Sivarani, Mario Juric, Amy Kimball, Gillian R. Knapp, Kevin R. Covey, Steve Kent, Donald G. York, Timothy C. Beers, John E. Norris, Jonathan Brinkmann, Daryl Haggard, Masayuki Tanaka, Howard Brewington, Harkirat Sohi, and Zeljko Ivezic
Subjects: Physics, Proper motion, 010308 nuclear & particles physics, Milky Way, Metallicity, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galactic plane, 01 natural sciences, Stars, Space and Planetary Science, Monoceros Ring, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Halo, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Main sequence
Abstract: Using effective temperature and metallicity derived from SDSS spectra for ~60,000 F and G type main sequence stars (0.2, Comment: 40 pages, 21 figures, emulateApJ style, accepted to ApJ, high resolution figures are available from http://www.astro.washington.edu/ivezic/sdss/mw/astroph0804.3850
Published: 2008

50. QSO number counts to B<24.5 from hubble space telescope WFPC2 images

Author: Bernhard Beck-Winchatz and Scott F. Anderson
Subjects: Physics, Atmospheric Science, Hubble Deep Field, media_common.quotation_subject, Hubble Deep Field South, Aerospace Engineering, Astronomy, Astronomy and Astrophysics, Quasar, Astrophysics, Hubble Ultra-Deep Field, Galaxy, Stars, Geophysics, Space and Planetary Science, Sky, Position (vector), General Earth and Planetary Sciences, media_common
Abstract: We have conducted a survey for faint quasars to B
Published: 2008

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