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51. 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

52. APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy

Author: Verne V. Smith, Matthew Shetrone, Steven R. Majewski, Borja Anguiano, David L. Nidever, Gloria Delgado Inglada, Andres Almeida, Andrew McWilliam, Baitian Tang, Jon A. Holtzman, Dante Minniti, Patricia B. Tissera, Emma Fernández Alvar, Jennifer Sobeck, Giuseppina Battaglia, Sten Hasselquist, D. A. García-Hernández, Vinicius M. Placco, Carlos Allende Prieto, Doug Geisler, José G. Fernández-Trincado, Peter M. Frinchaboy, Sandro Villanova, Timothy C. Beers, Mathias Schultheis, and Leticia Carigi
Subjects: Physics, 010308 nuclear & particles physics, Red giant, Milky Way, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Giant star, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Abundance of the chemical elements, Galaxy, Stars, Space and Planetary Science, Abundance (ecology), Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, 010303 astronomy & astrophysics, Dwarf galaxy
Abstract: The Apache Point Observatory Galactic Evolution Experiment (APOGEE) provides the opportunity to measure elemental abundances for C, N, O, Na, Mg, Al, Si, P, K, Ca, V, Cr, Mn, Fe, Co, and Ni in vast numbers of stars. We analyze the chemical abundance patterns of these elements for 158 red giant stars belonging to the Sagittarius dwarf galaxy (Sgr). This is the largest sample of Sgr stars with detailed chemical abundances and the first time C, N, P, K, V, Cr, Co, and Ni have been studied at high-resolution in this galaxy. We find that the Sgr stars with [Fe/H] $\gtrsim$ -0.8 are deficient in all elemental abundance ratios (expressed as [X/Fe]) relative to the Milky Way, suggesting that Sgr stars observed today were formed from gas that was less enriched by Type II SNe than stars formed in the Milky Way. By examining the relative deficiencies of the hydrostatic (O, Na, Mg, and Al) and explosive (Si, P, K, and Mn) elements, our analysis supports the argument that previous generations of Sgr stars were formed with a top-light IMF, one lacking the most massive stars that would normally pollute the ISM with the hydrostatic elements. We use a simple chemical evolution model, flexCE to further backup our claim and conclude that recent stellar generations of Fornax and the LMC could also have formed according to a top-light IMF., Comment: 14 pages, 12 figures, accepted for publication in ApJ
Published: 2017
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53. The Gaia-ESO Survey: Exploring the complex nature and origins of the Galactic bulge populations

Author: Mathias Schultheis, Dante Minniti, A. Hourihane, Manuela Zoccali, Amelia Bayo, Francesco Damiani, Giovanni Carraro, C. C. Worley, Elena Pancino, Alejandra Recio-Blanco, Francesca Matteucci, Andrew R. Casey, Paula Jofre, G. G. Sacco, Thomas Bensby, Sergey E. Koposov, S. Mikolaitis, M. T. Costado, Carmela Lardo, L. Morbidelli, Paolo Donati, Vanessa Hill, Michael R. Hayden, Sofia Feltzing, P. de Laverny, Ettore Flaccomio, E. Spitoni, C. Babusiaux, Laura Magrini, Sofia Randich, Karin Lind, Jack Lewis, Gerard Gilmore, Emilio J. Alfaro, E. Franciosini, Oscar A. Gonzalez, Simone Zaggia, Angela Bragaglia, A. Rojas-Arriagada, Millennium Institute of Astrophysics, Instituto de Astrofisica [Santiago], Pontificia Universidad Católica de Chile (UC), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), University of Turin, Groupe d'études pour l'application des méthodes scientifiques à l'architecture et à l'urbanisme (GAMSAU), École nationale supérieure d'architecture de Marseille-Luminy (ENSA-M), Cognition Behaviour Technology (CobTek), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre Hospitalier Universitaire de Nice (CHU Nice)-Institut Claude Pompidou [Nice] (ICP - Nice)-Université Côte d'Azur (UCA), European Commission, European Research Council, Leverhulme Trust, Centre National de la Recherche Scientifique (France), Agence Nationale de la Recherche (France), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Rojas Arriagada, A., Recio Blanco, A., De Laverny, P., Mikolaitis, Š., Matteucci, MARIA FRANCESCA, Spitoni, Emanuele, Schultheis, M., Hayden, M., Hill, V., Zoccali, M., Minniti, D., Gonzalez, O. A., Gilmore, G., Randich, S., Feltzing, S., Alfaro, E. J., Babusiaux, C., Bensby, T., Bragaglia, A., Flaccomio, E., Koposov, S. E., Pancino, E., Bayo, A., Carraro, G., Casey, A. R., Costado, M. T., Damiani, F., Donati, P., Franciosini, E., Hourihane, A., Jofré, P., Lardo, C., Lewis, J., Lind, K., Magrini, L., Morbidelli, L., Sacco, G. G., Worley, C. C., Zaggia, S., Rojas-Arriagada A., Recio-Blanco A., De Laverny P., Mikolaitis S., Matteucci F., Spitoni E., Schultheis M., Hayden M., Hill V., Zoccali M., Minniti D., Gonzalez O.A., Gilmore G., Randich S., Feltzing S., Alfaro E.J., Babusiaux C., Bensby T., Bragaglia A., Flaccomio E., Koposov S.E., Pancino E., Bayo A., Carraro G., Casey A.R., Costado M.T., Damiani F., Donati P., Franciosini E., Hourihane A., Jofre P., Lardo C., Lewis J., Lind K., Magrini L., Morbidelli L., Sacco G.G., Worley C.C., Zaggia S., 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, 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), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre Hospitalier Universitaire de Nice (CHU Nice)-Institut Claude Pompidou [Nice] (ICP - Nice)
Subjects: stars: abundances, Galaxy: bulge, Galaxy: formation, Galaxy: abundances, Galaxy: stellar content, astro-ph.GA, bulge [Galaxy], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Bulge, 0103 physical sciences, Thick disk, stellar content [Galaxy], Astrophysics::Solar and Stellar Astrophysics, abundance [Galaxy], 010303 astronomy & astrophysics, Red clump, Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Star formation, Plane (geometry), abundances [Galaxy], Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Bimodality, Galaxy: abundance, Stars, Thin disk, formation [Galaxy], Space and Planetary Science, abundances [Stars], Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Full list of authors: Rojas-Arriagada, A.; Recio-Blanco, A.; de Laverny, P.; Mikolaitis, Š.; Matteucci, F.; Spitoni, E.; Schultheis, M.; Hayden, M.; Hill, V.; Zoccali, M.; Minniti, D.; Gonzalez, O. A.; Gilmore, G.; Randich, S.; Feltzing, S.; Alfaro, E. J.; Babusiaux, C.; Bensby, T.; Bragaglia, A.; Flaccomio, E. Koposov, S. E.; Pancino, E.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Donati, P.; Franciosini, E.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis, J.; Lind, K.; Magrini, L.; Morbidelli, L.; Sacco, G. G.; Worley, C. C.; Zaggia, S., Context. As observational evidence steadily accumulates, the nature of the Galactic bulge has proven to be rather complex: the structural, kinematic, and chemical analyses often lead to contradictory conclusions. The nature of the metal-rich bulge - and especially of the metal-poor bulge - and their relation with other Galactic components, still need to be firmly defined on the basis of statistically significant high-quality data samples. Aims. We used the fourth internal data release of the Gaia-ESO survey to characterize the bulge metallicity distribution function (MDF), magnesium abundance, spatial distribution, and correlation of these properties with kinematics. Moreover, the homogeneous sampling of the different Galactic populations provided by the Gaia-ESO survey allowed us to perform a comparison between the bulge, thin disk, and thick disk sequences in the [Mg/Fe] vs. [Fe/H] plane in order to constrain the extent of their eventual chemical similarities. Methods. We obtained spectroscopic data for ∼2500 red clump stars in 11 bulge fields, sampling the area -10° ≥ l ≥ +8° and -10° ≥ b ≥ -4° from the fourth internal data release of the Gaia-ESO survey. A sample of ∼6300 disk stars was also selected for comparison. Spectrophotometric distances computed via isochrone fitting allowed us to define a sample of stars likely located in the bulge region. Results. From a Gaussian mixture models (GMM) analysis, the bulge MDF is confirmed to be bimodal across the whole sampled area. The relative ratio between the two modes of the MDF changes as a function of b, with metal-poor stars dominating at high latitudes. The metal-rich stars exhibit bar-like kinematics and display a bimodality in their magnitude distribution, a feature which is tightly associated with the X-shape bulge. They overlap with the metal-rich end of the thin disk sequence in the [Mg/Fe] vs. [Fe/H] plane. On the other hand, metal-poor bulge stars have a more isotropic hot kinematics and do not participate in the X-shape bulge. Their Mg enhancement level and general shape in the [Mg/Fe] vs. [Fe/H] plane is comparable to that of the thick disk sequence. The position at which [Mg/Fe] starts to decrease with [Fe/H], called the "knee", is observed in the metal-poor bulge at [Fe/H] = -0:37 ± 0:09, being 0.06 dex higher than that of the thick disk. Although this difference is inside the error bars, it suggest a higher star formation rate (SFR) for the bulge than for the thick disk. We estimate an upper limit for this difference of Δ[Fe/H] = 0:24 dex. Finally, we present a chemical evolution model that suitably fits the whole bulge sequence by assuming a fast (, This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and the Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR) in the form of the grant "Premiale VLT 2012". The results presented here benefited from discussions held during the Gaia-ESO workshops and conferences supported by the ESF (European Science Foundation) through the GREAT Research Network Programme. A. Recio-Blanco, P. de Laverny, and V. Hill acknowledge the Programme National de Cosmologie et Galaxies (PNCG) of CNRS/INSU, France, for financial support. A. Recio-Blanco, P. de Laverny, and V. Hill acknowledge financial support form the ANR 14-CE33-014-01. M. Zoccali gratefully acknowledges support from the Ministry of Economy, Development, and Tourism's Millenium Science Initiative through grant IC120009, awarded to the Millenium Institute of Astrophysics (MAS), by Fondecyt Regular 1150345 and by the BASAL-CATA Center for Astrophysics and Associated Technologies PFB-06.
Published: 2017

54. Chemical abundances and ages of the bulge stars in APOGEE high-velocity peaks

Author: R. Michael Rich, Steven R. Majewski, Shude Mao, Baitian Tang, Kaike Pan, Juntai Shen, Dmitry Bizyaev, Zhao-Yu Li, Andres Meza, Mathias Schultheis, Alexandre Roman-Lopes, Sandro Villanova, Andrea Kunder, Doug Geisler, Yingying Zhou, Chao Liu, José G. Fernández-Trincado, David L. Nidever, Chien-Cheng Lin, and Gail Zasowski
Subjects: Physics, Low latitude, 010308 nuclear & particles physics, High velocity, Metallicity, bulge [Galaxy], abundances [Galaxy], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, kinematics and dynamics [Galaxy], 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Skewness, Bulge, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Bar (unit), structure [Galaxy]
Abstract: A cold high-velocity (HV, $\sim$ 200 km/s) peak was first reported in several Galactic bulge fields based on the APOGEE commissioning observations. Both the existence and the nature of the high-velocity peak are still under debate. Here we revisit this feature with the latest APOGEE DR13 data. We find that most of the low latitude bulge fields display a skewed Gaussian distribution with a HV shoulder. However, only 3 out of 53 fields show distinct high-velocity peaks around 200 km/s. The velocity distribution can be well described by Gauss-Hermite polynomials, except the three fields showing clear HV peaks. We find that the correlation between the skewness parameter ($h_{3}$) and the mean velocity ($\bar{v}$), instead of a distinctive HV peak, is a strong indicator of the bar. It was recently suggested that the HV peak is composed of preferentially young stars. We choose three fields showing clear HV peaks to test this hypothesis using the metallicity, [$\alpha$/M] and [C/N] as age proxies. We find that both young and old stars show HV features. The similarity between the chemical abundances of stars in the HV peaks and the main component indicates that they are not systematically different in terms of chemical abundance or age. In contrast, there are clear differences in chemical space between stars in the Sagittarius dwarf and the bulge stars. The strong HV peaks off-plane are still to be explained properly, and could be different in nature., Comment: 13 pages, 10 figures, published in ApJ. Updated to match the final ApJ published version. Minor revisions to the text and Figure 4
Published: 2017
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55. Characterizing solar-type stars from full-length Kepler data sets using the Asteroseismic Modeling Portal

Author: Orlagh Creevey, Rafael A. García, David Salabert, Travis S. Metcalfe, Mathias Schultheis, Michael Bazot, Haiying Xu, Frédéric Thévenin, Savita Mathur, Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), 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 Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and 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)
Subjects: FOS: Physical sciences, Astrophysics, asteroseismology, Type (model theory), stars: interiors, 01 natural sciences, Kepler, Asteroseismology, methods: numerical, Spitzer Space Telescope, Frequency separation, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Variation (astronomy), 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010308 nuclear & particles physics, Astronomy and Astrophysics, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Data analysis, Astrophysics::Earth and Planetary Astrophysics, stars: fundamental parameters, stars: oscillations, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: The Kepler space telescope yielded unprecedented data for the study of solar-like oscillations in other stars. The large samples of multi-year observations posed an enormous data analysis challenge that has only recently been surmounted. Asteroseismic modeling has become more sophisticated over time, with better methods gradually developing alongside the extended observations and improved data analysis techniques. We apply the latest version of the Asteroseismic Modeling Portal (AMP) to the full-length Kepler data sets for 57 stars and the Sun, comprising planetary hosts, binaries, solar-analogs, and active stars. From an analysis of the derived stellar properties for the full sample, we identify a variation of the mixing-length parameter with atmospheric properties. We also derive a linear relation between the stellar age and a characteristic frequency separation ratio. In addition, we find that the empirical correction for surface effects suggested by Kjeldsen and coworkers is adequate for solar-type stars that are not much hotter (Teff < 6200 K) or significantly more evolved (logg > 4.2, > 80 muHz) than the Sun. Precise parallaxes from the Gaia mission and future observations from TESS and PLATO promise to improve the reliability of stellar properties derived from asteroseismology., Comment: A&A accepted
Published: 2017

56. The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

Author: Franco D. Albareti, Carlos Allende Prieto, Andres Almeida, Friedrich Anders, Scott Anderson, Brett H. Andrews, Alfonso Aragón-Salamanca, Maria Argudo-Fernández, Eric Armengaud, Eric Aubourg, Vladimir Avila-Reese, Carles Badenes, Stephen Bailey, Beatriz Barbuy, Kat Barger, Jorge Barrera-Ballesteros, Curtis Bartosz, Sarbani Basu, Dominic Bates, Giuseppina Battaglia, Falk Baumgarten, Julien Baur, Julian Bautista, Timothy C. Beers, Francesco Belfiore, Matthew Bershady, Sara Bertran de Lis, Jonathan C. Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael Blanton, Michael Blomqvist, Adam S. Bolton, J. Borissova, Jo Bovy, William Nielsen Brandt, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Etienne Burtin, Nicolás G. Busca, Hugo Orlando Camacho Chavez, M. Cano Díaz, Michele Cappellari, Ricardo Carrera, Yanping Chen, Brian Cherinka, Edmond Cheung, Cristina Chiappini, Drew Chojnowski, Chia-Hsun Chuang, Haeun Chung, Rafael Fernando Cirolini, Nicolas Clerc, Roger E. Cohen, Julia M. Comerford, Johan Comparat, Janaina Correa do Nascimento, Marie-Claude Cousinou, Kevin Covey, Jeffrey D. Crane, Rupert Croft, Katia Cunha, Jeremy Darling, James W. Davidson, Kyle Dawson, Luiz Da Costa, Gabriele Da Silva Ilha, Alice Deconto Machado, Timothée Delubac, Nathan De Lee, Axel De la Macorra, Sylvain De la Torre, Aleksandar M. Diamond-Stanic, John Donor, Juan Jose Downes, Niv Drory, Cheng Du, Hélion Du Mas des Bourboux, Tom Dwelly, Garrett Ebelke, Arthur Eigenbrot, Daniel J. Eisenstein, Yvonne P. Elsworth, Eric Emsellem, Michael Eracleous, Stephanie Escoffier, Michael L. Evans, Jesús Falcón-Barroso, Xiaohui Fan, Ginevra Favole, Emma Fernandez-Alvar, J. G. Fernandez-Trincado, Diane Feuillet, Scott W. Fleming, Andreu Font-Ribera, Gordon Freischlad, Peter Frinchaboy, Hai Fu, Yang Gao, Rafael A. Garcia, R. Garcia-Dias, D. A. Garcia-Hernández, Ana E. Garcia Pérez, Patrick Gaulme, Junqiang Ge, Douglas Geisler, Bruce Gillespie, Hector Gil Marin, Léo Girardi, Daniel Goddard, Yilen Gomez Maqueo Chew, Violeta Gonzalez-Perez, Kathleen Grabowski, Paul Green, Catherine J. Grier, Thomas Grier, Hong Guo, Julien Guy, Alex Hagen, Matt Hall, Paul Harding, R. E. Harley, Sten Hasselquist, Suzanne Hawley, Christian R. Hayes, Fred Hearty, Saskia Hekker, Hector Hernandez Toledo, Shirley Ho, David W. Hogg, Kelly Holley-Bockelmann, Jon A. Holtzman, Parker H. Holzer, Jian Hu, Daniel Huber, Timothy Alan Hutchinson, Ho Seong Hwang, Héctor J. Ibarra-Medel, Inese I. Ivans, KeShawn Ivory, Kurt Jaehnig, Trey W. Jensen, Jennifer A. Johnson, Amy Jones, Eric Jullo, T. Kallinger, Karen Kinemuchi, David Kirkby, Mark Klaene, Jean-Paul Kneib, Juna A. Kollmeier, Ivan Lacerna, Richard R. Lane, Dustin Lang, Pierre Laurent, David R. Law, Alexie Leauthaud, Jean-Marc Le Goff, Chen Li, Cheng Li, Niu Li, Ran Li, Fu-Heng Liang, Yu Liang, Marcos Lima, Lihwai Lin, Lin Lin, Yen-Ting Lin, Chao Liu, Dan Long, Sara Lucatello, Nicholas MacDonald, Chelsea L. MacLeod, J. Ted Mackereth, Suvrath Mahadevan, Marcio Antonio Geimba Maia, Roberto Maiolino, Steven R. Majewski, Olena Malanushenko, Viktor Malanushenko, Nícolas Dullius Mallmann, Arturo Manchado, Claudia Maraston, Rui Marques-Chaves, Inma Martinez Valpuesta, Karen L. Masters, Savita Mathur, Ian D. McGreer, Andrea Merloni, Michael R. Merrifield, Szabolcs Meszáros, Andres Meza, Andrea Miglio, Ivan Minchev, Karan Molaverdikhani, Antonio D. Montero-Dorta, Benoit Mosser, Demitri Muna, Adam Myers, Preethi Nair, Kirpal Nandra, Melissa Ness, Jeffrey A. Newman, Robert C. Nichol, David L. Nidever, Christian Nitschelm, Julia O’Connell, Audrey Oravetz, Daniel J. Oravetz, Zachary Pace, Nelson Padilla, Nathalie Palanque-Delabrouille, Kaike Pan, John Parejko, Isabelle Paris, Changbom Park, John A. Peacock, Sebastien Peirani, Marcos Pellejero-Ibanez, Samantha Penny, Will J. Percival, Jeffrey W. Percival, Ismael Perez-Fournon, Patrick Petitjean, Matthew Pieri, Marc H. Pinsonneault, Alice Pisani, Francisco Prada, Abhishek Prakash, Natalie Price-Jones, M. Jordan Raddick, Mubdi Rahman, Anand Raichoor, Sandro Barboza Rembold, A. M. Reyna, James Rich, Hannah Richstein, Jethro Ridl, Rogemar A. Riffel, Rogério Riffel, Hans-Walter Rix, Annie C. Robin, Constance M. Rockosi, Sergio Rodríguez-Torres, Thaíse S. Rodrigues, Natalie Roe, A. Roman Lopes, Carlos Román-Zúñiga, Ashley J. Ross, Graziano Rossi, John Ruan, Rossana Ruggeri, Jessie C. Runnoe, Salvador Salazar-Albornoz, Mara Salvato, Sebastian F. Sanchez, Ariel G. Sanchez, José R. Sanchez-Gallego, Basílio Xavier Santiago, Ricardo Schiavon, Jaderson S. Schimoia, Eddie Schlafly, David J. Schlegel, Donald P. Schneider, Ralph Schönrich, Mathias Schultheis, Axel Schwope, Hee-Jong Seo, Aldo Serenelli, Branimir Sesar, Zhengyi Shao, Matthew Shetrone, Michael Shull, Victor Silva Aguirre, M. F. Skrutskie, Anže Slosar, Michael Smith, Verne V. Smith, Jennifer Sobeck, Garrett Somers, Diogo Souto, David V. Stark, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Thaisa Storchi Bergmann, Michael A. Strauss, Alina Streblyanska, Guy S. Stringfellow, Genaro Suarez, Jing Sun, Manuchehr Taghizadeh-Popp, Baitian Tang, Charling Tao, Jamie Tayar, Mita Tembe, Daniel Thomas, Jeremy Tinker, Rita Tojeiro, Christy Tremonti, Nicholas Troup, Jonathan R. Trump, Eduardo Unda-Sanzana, O. Valenzuela, Remco Van den Bosch, Mariana Vargas-Magaña, Jose Alberto Vazquez, Sandro Villanova, M. Vivek, Nicole Vogt, David Wake, Rene Walterbos, Yuting Wang, Enci Wang, Benjamin Alan Weaver, Anne-Marie Weijmans, David H. Weinberg, Kyle B. Westfall, David G. Whelan, Eric Wilcots, Vivienne Wild, Rob A. Williams, John Wilson, W. M. Wood-Vasey, Dominika Wylezalek, Ting Xiao, Renbin Yan, Meng Yang, Jason E. Ybarra, Christophe Yeche, Fang-Ting Yuan, Nadia Zakamska, Olga Zamora, Gail Zasowski, Kai Zhang, Cheng Zhao, Gong-Bo Zhao, Zheng Zheng, Zhi-Min Zhou, Guangtun Zhu, Joel C. Zinn, Hu Zou, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), 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), Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS 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), Laboratoire d'astrophysique de l'observatoire de Besançon (LAOB), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), 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), 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), 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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), 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), SDSS, Maiolino, Roberto [0000-0002-4985-3819], Apollo - University of Cambridge Repository, 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 de Paris (UP), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), 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)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (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), 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 Paris Cité (UPCité), 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), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université 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), 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), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), 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), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, AstroParticule et Cosmologie ( APC - UMR 7164 ), 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 Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Physique des Particules de Marseille ( CPPM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Aix Marseille Université ( AMU ), Centre de Recherche Astrophysique de Lyon ( CRAL ), École normale supérieure - Lyon ( ENS 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 ), Laboratoire d'astrophysique de l'observatoire de Besançon ( LAOB ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Laboratoire AIM, Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay, 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 ), 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 ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, and Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], media_common.quotation_subject, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, 01 natural sciences, Set (abstract data type), surveys, Observatory, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, QB, media_common, Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Atlases, DAS, Astronomy and Astrophysics, Quasar, GALÁXIAS, Galaxy, Redshift, atlases, QC Physics, Data access, Space and Planetary Science, Sky, Catalogs, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], catalogs, Data reduction
Abstract: The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV. Postprint
Published: 2017

57. Using Gaia to measure the atmospheric dynamics in AGB stars

Author: Mathias Schultheis, Bernd Freytag, and Andrea Chiavassa
Subjects: Physics, Convection, Astronomy and Astrophysics, 010103 numerical & computational mathematics, Function (mathematics), Astrophysics, Astrometry, Star (graph theory), 01 natural sciences, Measure (mathematics), Stars, Space and Planetary Science, 0103 physical sciences, Radiative transfer, 0101 mathematics, Parallax, 010303 astronomy & astrophysics
Abstract: We use 3D radiative-hydrodynamics simulations of convection with CO5BOLD and the post-processing radiative transfer code Optim3D to compute intensity maps in the Gaia G band [325–1030 nm]. We calculate the intensity-weighted mean of all emitting points tiling the visible stellar surface (i.e., the photo-center) and evaluate its motion as a function of time. We show that the convection-related variability accounts for a substantial part to the Gaia DR2 parallax error of our sample of semiregular variables. Finally, we denote that Gaia parallax variations could be exploited quantitatively to extract stellar parameters using appropriate RHD simulations corresponding to the observed star.
Published: 2018

58. The inner two degrees of the Milky Way

Author: R. M. Rich, Mathias Schultheis, B. Thorsbro, Livia Origlia, G. Nandakumar, Nils Ryde, Nadine Neumayer, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lund Observatory, and Lund University [Lund]
Subjects: stars: abundances, Metallicity, Milky Way, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy: bulge, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Spectroscopy, infrared: stars, 010303 astronomy & astrophysics, Stellar density, Astrophysics::Galaxy Astrophysics, Physics, Galaxy: stellar content, Galaxy: center, 010308 nuclear & particles physics, Galactic Center, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Stars, Star cluster, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), stars: fundamental parameters, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Although there have been numerous studies of chemical abundances in the Galactic bulge, the central two degrees have been relatively unexplored due to the heavy and variable interstellar extinction, extreme stellar crowding, and the presence of complex foreground disk stellar populations. In this paper we discuss the metallicity distribution function, vertical and radial gradients and chemical abundances of $\alpha$-elements in the inner two degrees of the Milky Way, as obtained by recent IR spectroscopic surveys. We use a compilation of recent measurements of metallicities and $\alpha$-element abundances derived from medium-high resolution spectroscopy. We compare these metallicities with low-resolution studies. Defining "metal-rich" as stars with $ \rm [Fe/H]>0$, and "metal-poor" as stars with $\rm [Fe/H], Comment: 9 pages, 8 figures, accepted for Astronomy&Astrophysics
Published: 2019

59. The bimodal [Mg/Fe] versus [Fe/H] bulge sequence as revealed by APOGEE DR14

Author: A. Rojas-Arriagada, Roger Cohen, Henrik Jönsson, Mathias Schultheis, Gail Zasowski, Manuela Zoccali, Alejandra Recio-Blanco, and Dante Minniti
Subjects: Physics, 010308 nuclear & particles physics, Plane (geometry), Metallicity, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Bimodality, Stars, Space and Planetary Science, Abundance (ecology), Bulge, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The Galactic bulge has a bimodal metallicity distribution function: different kinematic, spatial, and, potentially, age distributions characterize the metal-poor and metal-rich components. Despite this observed dichotomy, which argues for different formation channels for those stars, the distribution of bulge stars in the $\alpha$-abundance versus metallicity plane has been found so far to be a rather smooth single sequence. We use data from the fourteenth data release of the APOGEE spectroscopic survey (DR14) to investigate the distribution in the Mg abundance (as tracer of the $\alpha$-elements)-versus-metallicity plane of a sample of stars selected to be in the inner region of the bulge. A clean sample has been selected from the DR14 using a set of data- and pipeline-flags to ensure the quality of their fundamental parameters and elemental abundances. An additional selection made use of computed spectro-photometric distances to select a sample of likely bulge stars as those with ${\rm R_{GC}\leq 3.5~kpc}$. We adopt magnesium abundance as an $\alpha$-abundance proxy for our clean sample as it has been proven to be the most accurate $\alpha$-element as determined by ASPCAP, the pipeline for data products from APOGEE spectra. From the distribution of our bulge sample in the [Mg/Fe]-versus-[Fe/H] plane, we found that the sequence is bimodal. This bimodality is given by the presence of a low-Mg sequence of stars parallel to the main high-Mg sequence over a range of $\sim 0.5$~dex around solar metallicity. The two sequences merge above ${\rm [Fe/H]\sim0.15~ dex}$ into a single sequence whose dispersion in [Mg/Fe] is larger than either of the two sequences visible at lower metallicity. This result is confirmed when we consider stars in our sample that are inside the bulge region according to trustworthy Gaia DR2 distances., Comment: accepted for publication in A&A. 11 pages, 8 figures
Published: 2019

60. Large–scale and high–sensitivity multi–line CO surveys toward the Galactic center

Author: Takio Okuda, Kengo Tachihara, Ryoji Matsumoto, Mark Morris, Hiroaki Yamamoto, Mathias Schultheis, Kazufumi Torii, Yasuo Fukui, Yuta Asahina, and Rei Enokiya
Subjects: Physics, High intensity, Galactic Center, Astronomy, Astronomy and Astrophysics, Scale (descriptive set theory), Astrophysics, Latitude, Magnetic field, law.invention, Telescope, Space and Planetary Science, law, Halo, Line (formation)
Abstract: We carried out large–scale (4 × 2 degree) CO multi–line observations toward the central molecular zone (CMZ) in the Galactic center (GC) with the NANTEN2 4m telescope and mapped several diffuse molecular features located at relatively high Galactic latitudes above 0°.6. These high–latitude features are composed of diffuse molecular halo gas and molecular filaments according to their morphological aspects. Their high velocities and high intensity ratios between 12CO J = (2−1) and J = (1−0) clearly indicate their location in the GC, and their total mass amount to ∼10% of that of the CMZ. We discuss that magnetic field is a possible mechanism of these high–latitude molecular features lifting up toward high galactic latitude.
Published: 2013

61. Detailed abundance analysis of a metal-poor giant in the Galactic Center

Author: Livia Origlia, Tobias K. Fritz, Mathias Schultheis, S. Chatzopoulos, R. M. Rich, Nils Ryde, and B. Thorsbro
Subjects: Physics, 010308 nuclear & particles physics, Star formation, Red giant, Metallicity, Milky Way, Galactic Center, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Stars, Star cluster, Space and Planetary Science, Bulge, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: We report the first results from our program to examine the metallicity distribution of the Milky Way nuclear star cluster connected to SgrA*, with the goal of inferring the star formation and enrichment history of this system, as well as its connection and relationship with the central 100 pc of the bulge/bar system. We present the first high resolution (R~24,000), detailed abundance analysis of a K=10.2 metal-poor, alpha-enhanced red giant projected at 1.5 pc from the Galactic Center, using NIRSPEC on Keck II. A careful analysis of the dynamics and color of the star locates it at about 26 pc line-of-sight distance in front of the nuclear cluster. It probably belongs to one of the nuclear components (cluster or disk), not to the bar-bulge or classical disk. A detailed spectroscopic synthesis, using a new linelist in the K band, finds [Fe/H]~-1.0 and [alpha/Fe]~+0.4, consistent with stars of similar metallicity in the bulge. As known giants with comparable [Fe/H] and alpha enhancement are old, we conclude that this star is most likely to be a representative of the ~10 Gyr old population. This is also the most metal poor confirmed red giant yet discovered in vicinity of the nuclear cluster of the Galactic Center. We consider recent reports in the literature of a surprisingly large number of metal poor giants in the Galactic Center, but the reported gravities of log g ~4 for these stars calls into question their reported metallicities., Accepted for publication in ApJ
Published: 2016

62. Temperatures and metallicities of M giants in the galactic Bulge from low-resolution K-band spectra

Author: Mathias Schultheis, Nils Ryde, and G. Nandakumar
Subjects: Physics, 010308 nuclear & particles physics, Metallicity, Overtone, Extinction (astronomy), FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Spectral line, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Bulge, Astrophysics of Galaxies (astro-ph.GA), K band, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Spectral resolution, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: With the existing and upcoming large multi-fibre low-resolution spectrographs, the question arises how precise stellar parameters such as Teff and [Fe/H] can be obtained from low-resolution K-band spectra with respect to traditional photometric temperature measurements. Until now, most of the effective temperatures in galactic Bulge studies come directly from photometric techniques. Uncertainties in interstellar reddening and in the assumed extinction law could lead to large systematic errors. We aim to obtain and calibrate the relation between Teff and the $\rm ^{12}CO$ first overtone bands for M giants in the galactic Bulge covering a wide range in metallicity. We use low-resolution spectra for 20 M giants with well-studied parameters from photometric measurements covering the temperature range 3200 < Teff < 4500 K and a metallicity range from 0.5 dex down to -1.2 dex and study the behaviour of Teff and [Fe/H] on the spectral indices. We find a tight relation between Teff and the $\rm ^{12}CO(2-0)$ band with a dispersion of 95 K as well as between Teff and the $\rm ^{12}CO(3-1)$ with a dispersion of 120 K. We do not find any dependence of these relations on the metallicity of the star, making them relation attractive for galactic Bulge studies. This relation is also not sensitive to the spectral resolution allowing to apply this relation in a more general way. We also found a correlation between the combination of the NaI, CaI and the $\rm ^{12}CO$ band with the metallicity of the star. However this relation is only valid for sub-solar metallicities. We show that low-resolution spectra provide a powerful tool to obtain effective temperatures of M giants. We show that this relation does not depend on the metallicity of the star within the investigated range and is also applicable to different spectral resolution., 6 pages, accepted for publication in Astronomy&Astrophysics
Published: 2016

63. The Gaia-ESO Survey : Separating disk chemical substructures with cluster models. Evidence of a separate evolution in the metal-poor thin disk

Author: Vanessa Hill, E. Franciosini, P. de Laverny, Mathias Schultheis, John D. Lewis, Carmela Lardo, Georges Kordopatis, M. T. Costado, Simone Zaggia, Sofia Randich, Cristina Chiappini, Karin Lind, Gerard Gilmore, A. Hourihane, Sergey E. Koposov, Laura Magrini, Lorenzo Monaco, Alejandra Recio-Blanco, Šarūnas Mikolaitis, Thomas Bensby, Guillaume Guiglion, C. C. Worley, Paula Jofre, Emilio J. Alfaro, A. Rojas-Arriagada, G. G. Sacco, L. Morbidelli, Rojas-Arriagada A., Recio-Blanco A., De Laverny P., Schultheis M., Guiglion G., Mikolaitis S., Kordopatis G., Hill V., Gilmore G., Randich S., Alfaro E.J., Bensby T., Koposov S.E., Costado M.T., Franciosini E., Hourihane A., Jofre P., Lardo C., Lewis J., Lind K., Magrini L., Monaco L., Morbidelli L., Sacco G.G., Worley C.C., Zaggia S., and Chiappini C.
Subjects: 010504 meteorology & atmospheric sciences, Metallicity, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astronomi, astrofysik och kosmologi, 0103 physical sciences, Thick disk, Astrophysics::Solar and Stellar Astrophysics, stellar content [Galaxy], Astronomy, Astrophysics and Cosmology, Disc, 010303 astronomy & astrophysics, Red clump, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Galaxy: stellar content, Stars: abundances, abundances [Galaxy], Astronomy and Astrophysics, Scale height, Galaxy: abundance, abundances [stars], Stars, Thin disk, formation [Galaxy], Galaxy: formation, 13. Climate action, Space and Planetary Science, Halo, Astrophysics::Earth and Planetary Astrophysics
Abstract: Context. Recent spectroscopic surveys have begun to explore the Galactic disk system on the basis of large data samples, with spatial distributions sampling regions well outside the solar neighborhood. In this way, they provide valuable information for testing spatial and temporal variations of disk structure kinematics and chemical evolution. Aims: The main purposes of this study are to demonstrate the usefulness of a rigorous mathematical approach to separate substructures of a stellar sample in the abundance-metallicity plane, and provide new evidence with which to characterize the nature of the metal-poor end of the thin disk sequence. Methods: We used a Gaussian mixture model algorithm to separate in the [Mg/Fe] vs. [Fe/H] plane a clean disk star subsample (essentially at R_GC<< 10 kpc) from the Gaia-ESO survey (GES) internal data release 2 (iDR2). We aim at decomposing it into data groups highlighting number density and/or slope variations in the abundance-metallicity plane. An independent sample of disk red clump stars from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) was used to cross-check the identified features. Results: We find that the sample is separated into five groups associated with major Galactic components; the metal-rich end of the halo, the thick disk, and three subgroups for the thin disk sequence. This is confirmed with the sample of red clump stars from APOGEE. The three thin disk groups served to explore this sequence in more detail. The two metal-intermediate and metal-rich groups of the thin disk decomposition ([Fe/H] > -0.25 dex) highlight a change in the slope at solar metallicity. This holds true at different radial regions of the Milky Way. The distribution of Galactocentric radial distances of the metal-poor part of the thin disk ([Fe/H] < -0.25 dex) is shifted to larger distances than those of the more metal-rich parts. Moreover, the metal-poor part of the thin disk presents indications of a scale height intermediate between those of the thick and the rest of the thin disk, and it displays higher azimuthal velocities than the latter. These stars might have formed and evolved in parallel and/or dissociated from the inside-out formation taking place in the internal thin disk. Their enhancement levels might be due to their origin from gas pre-enriched by outflows from the thick disk or the inner halo. The smooth trends of their properties (their spatial distribution with respect to the plane, in particular) with [Fe/H] and [Mg/Fe] suggested by the data indicates a quiet dynamical evolution, with no relevant merger events. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002. These data products have been processed by the Cambridge Astronomy Survey Unit (CASU) at the Institute of Astronomy, University of Cambridge, and by the FLAMES/UVES reduction team at INAF/Osservatorio Astrofisico di Arcetri. These data have been obtained from the Gaia-ESO Survey Data Archive, prepared and hosted by the Wide Field Astronomy Unit, Institute for Astronomy, University of Edinburgh, which is funded by the UK Science and Technology Facilities Council.
Published: 2016

64. Developing an astrophysical line list for Keck/Nirspec observations of red giants in the Galactic centre

Author: R. M. Rich, B. Thorsbro, Mathias Schultheis, Tobias K. Fritz, Nils Ryde, and Livia Origlia
Subjects: Physics, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Line list, Space and Planetary Science, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: A major avenue in the study of the Galaxy is the investigation of stellar populations and Galactic chemical evolution by stellar spectroscopy. Due to the dust obscuration, stars in the centre of the Galaxy can only be observed in the near-IR wavelength region. However, existing line lists in this wavelength region are demonstratively not of good enough quality for use in stellar spectroscopy. In response to this, we have developed an empirical astrophysical line list in the K-band based on modelling against the Sun and testing against Arcturus. Of ca. 700 identified interesting lines about 570 lines have been assigned empirically determined values.
Published: 2017

65. What the Milky Way bulge reveals about the initial metallicity gradients in the disc

Author: Sergey Khoperskov, A. E. Gomez, F. Fragkoudi, Mathias Schultheis, Francoise Combes, B. Semelin, M. Haywood, P. Di Matteo, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), 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), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), École normale supérieure - Paris (ENS-PSL), and Collège de France - Chaire Galaxies et cosmologie
Subjects: 010504 meteorology & atmospheric sciences, Stellar mass, Bar (music), Metallicity, Milky Way, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy: bulge, Galaxy: disk, Bulge, 0103 physical sciences, Galaxy formation and evolution, Disc, Galaxy: structure, Galaxy: general, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Galaxy: evolution, Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy: abundances, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We examine the metallicity trends in the Milky Way (MW) bulge - using APOGEE DR13 data - and explore their origin by comparing two N-body models of isolated galaxies which develop a bar and a boxy/peanut (b/p) bulge. Both models have been proposed as scenarios for reconciling a disc origin of the MW bulge with a negative vertical metallicity gradient. The first model is a superposition of co-spatial, i.e. overlapping, disc populations with different scaleheights, kinematics and metallicities. In this model the thick, metal-poor, and centrally concentrated disc populations contribute significantly to the stellar mass budget in the inner galaxy. The second model is a single disc with an initial steep radial metallicity gradient, which is mapped by the bar into the b/p bulge in such a way that the vertical metallicity gradient of the MW bulge is reproduced -- as shown already in previous works in the literature. However, as we show here, the latter model does not reproduce the positive longitudinal metallicity gradient of the inner disc, nor the metal-poor innermost regions of the Bulge seen in the data. On the other hand, the model with co-spatial thin and thick disc populations reproduces all the aforementioned trends. We therefore see that it is possible to reconcile a (primarily) disc origin for the MW bulge with the observed trends in metallicity by mapping the inner thin and thick discs of the MW into a b/p. For this scenario to reproduce the observations, the $\alpha$-enhanced, metal-poor, thick disc populations must have a significant mass contribution in the inner regions -- as has been suggested for the Milky Way., Comment: 6 pages, accepted for publication in A&A Letters
Published: 2017

66. The Milky Way's external disc constrained by 2MASS star counts

Author: Annie C. Robin, Douglas J. Marshall, Mathias Schultheis, Céline Reylé, 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), Université Laval [Québec] (ULaval), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)
Subjects: Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Stellar population, 010308 nuclear & particles physics, Milky Way, Astrophysics (astro-ph), Extinction (astronomy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Star count, Radius, Galactic plane, 01 natural sciences, Galaxy, Stars, Space and Planetary Science, 0103 physical sciences, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics
Abstract: Context. Thanks to recent large scale surveys in the near infrared such as 2MASS, the galactic plane that most suffers from extinction is revealed and its overall structure can be studied. Aims. This work aims at constraining the structure of the Milky Way external disc as seen in 2MASS data, and in particular the warp. Methods. We use the Two Micron All Sky Survey (hereafter 2MASS) along with the Stellar Population Synthesis Model of the Galaxy, developed in Besancon, to constrain the external disc parameters such as its scale length, its cutoff radius, and the slope of the warp. In order to properly interpret the observations, the simulated stars are reddened using a three dimensional extinction map. The shape of the stellar warp is then compared with previous results and with similar structures in gas and dust. Results. We find new constraints on the stellar disc, which is shown to be asymmetrical, similar to observations of HI. The positive longitude side is found to be easily modelled with a S shape warp but with a slope significantly smaller than the slope seen in the HI warp. At negative longitudes, the disc presents peculiarities which are not well reproduced by any simple model. Finally, comparing with the warp seen in the dust, it seems to follow a slope intermediate between the gas and the stars., 9 pages. Accepted for publication in Astronomy and Astrophysics
Published: 2009

67. Evidence for a metal-poor population in the inner Galactic Bulge

Author: Katia Cunha, Matthew Shetrone, Verne V. Smith, Kris Sellgren, Olga Zamora, Gail Zasowski, Mathias Schultheis, A. E. Garcia Perez, Karen Kinemuchi, C. Allende Prieto, Viktor Malanushenko, Kaike Pan, Friedrich Anders, Dmitry Bizyaev, Elena Malanushenko, D. A. García-Hernández, and Tobias K. Fritz
Subjects: Physics, education.field_of_study, Metallicity, Population, Galactic Center, Extinction (astronomy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Observatory, Bulge, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, education, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: The inner Galactic Bulge has, until recently, been avoided in chemical evolution studies due to extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as APOGEE, allow for the first time the measurement of metallicities in the inner region of our Galaxy. We study metallicities of 33 K/M giants situated in the Galactic Center region from observations obtained with the APOGEE survey. We selected K/M giants with reliable stellar parameters from the APOGEE/ASPCAP pipeline. Distances, interstellar extinction values, and radial velocities were checked to confirm that these stars are indeed situated in the inner Galactic Bulge. We find a metal-rich population centered at [M/H] = +0.4 dex, in agreement with earlier studies of other bulge regions, but also a peak at low metallicity around $\rm [M/H] = -1.0\,dex$, suggesting the presence of a metal-poor population which has not previously been detected in the central region. Our results indicate a dominant metal-rich population with a metal-poor component that is enhanced in the $\alpha$-elements. This metal-poor population may be associated with the classical bulge and a fast formation scenario., Comment: 5 pages, 5 figures, accepted for publication in Astronomy&Astrophysics
Published: 2015

68. The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III

Author: Shadab Alam, Franco D. Albareti, Carlos Allende Prieto, F. Anders, Scott F. Anderson, Timothy Anderton, Brett H. Andrews, Eric Armengaud, Éric Aubourg, Stephen Bailey, Sarbani Basu, Julian E. Bautista, Rachael L. Beaton, Timothy C. Beers, Chad F. Bender, Andreas A. Berlind, Florian Beutler, Vaishali Bhardwaj, Jonathan C. Bird, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, John J. Bochanski, Adam S. Bolton, Jo Bovy, A. Shelden Bradley, W. N. Brandt, D. E. Brauer, J. Brinkmann, Peter J. Brown, Joel R. Brownstein, Angela Burden, Etienne Burtin, Nicolás G. Busca, Zheng Cai, Diego Capozzi, Aurelio Carnero Rosell, Michael A. Carr, Ricardo Carrera, K. C. Chambers, William James Chaplin, Yen-Chi Chen, Cristina Chiappini, S. Drew Chojnowski, Chia-Hsun Chuang, Nicolas Clerc, Johan Comparat, Kevin Covey, Rupert A. C. Croft, Antonio J. Cuesta, Katia Cunha, Luiz N. da Costa, Nicola Da Rio, James R. A. Davenport, Kyle S. Dawson, Nathan De Lee, Timothée Delubac, Rohit Deshpande, Saurav Dhital, Letícia Dutra-Ferreira, Tom Dwelly, Anne Ealet, Garrett L. Ebelke, Edward M. Edmondson, Daniel J. Eisenstein, Tristan Ellsworth, Yvonne Elsworth, Courtney R. Epstein, Michael Eracleous, Stephanie Escoffier, Massimiliano Esposito, Michael L. Evans, Xiaohui Fan, Emma Fernández-Alvar, Diane Feuillet, Nurten Filiz Ak, Hayley Finley, Alexis Finoguenov, Kevin Flaherty, Scott W. Fleming, Andreu Font-Ribera, Jonathan Foster, Peter M. Frinchaboy, J. G. Galbraith-Frew, Rafael A. García, D. A. García-Hernández, Ana E. García Pérez, Patrick Gaulme, Jian Ge, R. Génova-Santos, A. Georgakakis, Luan Ghezzi, Bruce A. Gillespie, Léo Girardi, Daniel Goddard, Satya Gontcho A Gontcho, Jonay I. González Hernández, Eva K. Grebel, Paul J. Green, Jan Niklas Grieb, Nolan Grieves, James E. Gunn, Hong Guo, Paul Harding, Sten Hasselquist, Suzanne L. Hawley, Michael Hayden, Fred R. Hearty, Saskia Hekker, Shirley Ho, David W. Hogg, Kelly Holley-Bockelmann, Jon A. Holtzman, Klaus Honscheid, Daniel Huber, Joseph Huehnerhoff, Inese I. Ivans, Linhua Jiang, Jennifer A. Johnson, Karen Kinemuchi, David Kirkby, Francisco Kitaura, Mark A. Klaene, Gillian R. Knapp, Jean-Paul Kneib, Xavier P. Koenig, Charles R. Lam, Ting-Wen Lan, Dustin Lang, Pierre Laurent, Jean-Marc Le Goff, Alexie Leauthaud, Khee-Gan Lee, Young Sun Lee, Timothy C. Licquia, Jian Liu, Daniel C. Long, Martín López-Corredoira, Diego Lorenzo-Oliveira, Sara Lucatello, Britt Lundgren, Robert H. Lupton, Claude E. Mack III, Suvrath Mahadevan, Marcio A. G. Maia, Steven R. Majewski, Elena Malanushenko, Viktor Malanushenko, A. Manchado, Marc Manera, Qingqing Mao, Claudia Maraston, Robert C. Marchwinski, Daniel Margala, Sarah L. Martell, Marie Martig, Karen L. Masters, Savita Mathur, Cameron K. McBride, Peregrine M. McGehee, Ian D. McGreer, Richard G. McMahon, Brice Ménard, Marie-Luise Menzel, Andrea Merloni, Szabolcs Mészáros, Adam A. Miller, Jordi Miralda-Escudé, Hironao Miyatake, Antonio D. Montero-Dorta, Surhud More, Eric Morganson, Xan Morice-Atkinson, Heather L. Morrison, Benôit Mosser, Demitri Muna, Adam D. Myers, Kirpal Nandra, Jeffrey A. Newman, Mark Neyrinck, Duy Cuong Nguyen, Robert C. Nichol, David L. Nidever, Pasquier Noterdaeme, Sebastián E. Nuza, Julia E. O’Connell, Robert W. O’Connell, Ross O’Connell, Ricardo L. C. Ogando, Matthew D. Olmstead, Audrey E. Oravetz, Daniel J. Oravetz, Keisuke Osumi, Russell Owen, Deborah L. Padgett, Nikhil Padmanabhan, Martin Paegert, Nathalie Palanque-Delabrouille, Kaike Pan, John K. Parejko, Isabelle Pâris, Changbom Park, Petchara Pattarakijwanich, M. Pellejero-Ibanez, Joshua Pepper, Will J. Percival, Ismael Pérez-Fournon, Ignasi Pe´rez-Ra`fols, Patrick Petitjean, Matthew M. Pieri, Marc H. Pinsonneault, Gustavo F. Porto de Mello, Francisco Prada, Abhishek Prakash, Adrian M. Price-Whelan, Pavlos Protopapas, M. Jordan Raddick, Mubdi Rahman, Beth A. Reid, James Rich, Hans-Walter Rix, Annie C. Robin, Constance M. Rockosi, Thaíse S. Rodrigues, Sergio Rodríguez-Torres, Natalie A. Roe, Ashley J. Ross, Nicholas P. Ross, Graziano Rossi, John J. Ruan, J. A. Rubiño-Martín, Eli S. Rykoff, Salvador Salazar-Albornoz, Mara Salvato, Lado Samushia, Ariel G. Sánchez, Basílio Santiago, Conor Sayres, Ricardo P. Schiavon, David J. Schlegel, Sarah J. Schmidt, Donald P. Schneider, Mathias Schultheis, Axel D. Schwope, C. G. Scóccola, Caroline Scott, Kris Sellgren, Hee-Jong Seo, Aldo Serenelli, Neville Shane, Yue Shen, Matthew Shetrone, Yiping Shu, V. Silva Aguirre, Thirupathi Sivarani, M. F. Skrutskie, Anže Slosar, Verne V. Smith, Flávia Sobreira, Diogo Souto, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Michael A. Strauss, Alina Streblyanska, Nao Suzuki, Molly E. C. Swanson, Jonathan C. Tan, Jamie Tayar, Ryan C. Terrien, Aniruddha R. Thakar, Daniel Thomas, Neil Thomas, Benjamin A. Thompson, Jeremy L. Tinker, Rita Tojeiro, Nicholas W. Troup, Mariana Vargas-Magaña, Jose A. Vazquez, Licia Verde, Matteo Viel, Nicole P. Vogt, David A. Wake, Ji Wang, Benjamin A. Weaver, David H. Weinberg, Benjamin J. Weiner, Martin White, John C. Wilson, John P. Wisniewski, W. M. Wood-Vasey, Christophe Ye`che, Donald G. York, Nadia L. Zakamska, O. Zamora, Gail Zasowski, Idit Zehavi, Gong-Bo Zhao, Zheng Zheng, Xu Zhou (周旭), Zhimin Zhou (周志民), Hu Zou (邹虎), Guangtun Zhu, UAM. Departamento de Física Teórica, University of St Andrews. School of Physics and Astronomy, 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), SDSS Collaboration, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), 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), ITA, USA, GBR, FRA, DEU, ESP, CHN, and Department of Physics
Subjects: 10TH DATA RELEASE, OSCILLATION SPECTROSCOPIC SURVEY, purl.org/becyt/ford/1 [https], SOLAR-LIKE STARS, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, ComputingMilieux_MISCELLANEOUS, QC, QB, media_common, Physics, Astrophysics::Instrumentation and Methods for Astrophysics, Celestial sphere, Composicao estelar, Exoplanet, Radial velocity, atlases, Astrophysics - Solar and Stellar Astrophysics, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, MAIN-SEQUENCE STARS, FIXED-DELAY INTERFEROMETRY, Cosmology and Gravitation, astro-ph.SR, GALACTIC EVOLUTION EXPERIMENT, astro-ph.GA, media_common.quotation_subject, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, catalogs, surveys, Movimento estelar, Settore FIS/05 - Astronomia e Astrofisica, BROWN DWARF CANDIDATE, LOW-MASS STELLAR, ST/J500665/1, Galáxias, Instrumentation and Methods for Astrophysics (astro-ph.IM), Quasars, Spectrograph, STFC, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], RCUK, Astronomy, Física, DAS, Astronomy and Astrophysics, Quasar, purl.org/becyt/ford/1.3 [https], 115 Astronomy, Space science, Astrophysics - Astrophysics of Galaxies, Espectros estelares, Galaxy, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 1ST DATA RELEASE, Stars, QC Physics, 13. Climate action, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), Catalogos astronomicos, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], BARYON ACOUSTIC-OSCILLATIONS, astro-ph.IM
Abstract: The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 sq. deg of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-Object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include measured abundances of 15 different elements for each star. In total, SDSS-III added 2350 sq. deg of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 sq. deg; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5,513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra., Comment: DR12 data are available at http://www.sdss3.org/dr12. 30 pages. 11 figures. Accepted to ApJS
Published: 2015

69. Chemical evolution of the Galactic Centre

Author: Nils Ryde, Mathias Schultheis, S. Uttenthaler, V. Grieco, Francesca Matteucci, Grieco, V., Matteucci, MARIA FRANCESCA, Ryde, N., Schultheis, M., and Uttenthaler, S.
Subjects: Physics, Galaxy: evolution, Star formation, Metallicity distribution function, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy and Astrophysic, Astrophysics - Astrophysics of Galaxies, Accretion (astrophysics), evolution [Galaxy], Chemical evolution, Stars, Bulge, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, Galaxy: abundances, abundance [Galaxy], Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: In recent years, the Galactic Center (GC) region (200 pc in radius) has been studied in detail with spectroscopic stellar data as well as an estimate of the ongoing star formation rate. The aims of this paper are to study the chemical evolution of the GC region by means of a detailed chemical evolution model and to compare the results with high resolution spectroscopic data in order to impose constraints on the GC formation history.The chemical evolution model assumes that the GC region formed by fast infall of gas and then follows the evolution of alpha-elements and Fe. We test different initial mass functions (IMFs), efficiencies of star formation and gas infall timescales. To reproduce the currently observed star formation rate, we assume a late episode of star formation triggered by gas infall/accretion. We find that, in order to reproduce the [alpha/Fe] ratios as well as the metallicity distribution function observed in GC stars, the GC region should have experienced a main early strong burst of star formation, with a star formation efficiency as high as 25 Gyr^{-1}, occurring on a timescale in the range 0.1-0.7 Gyr, in agreement with previous models of the entire bulge. Although the small amount of data prevents us from drawing firm conclusions, we suggest that the best IMF should contain more massive stars than expected in the solar vicinity, and the last episode of star formation, which lasted several hundred million years, should have been triggered by a modest episode of gas infall/accretion, with a star formation efficiency similar to that of the previous main star formation episode. This last episode of star formation produces negligible effects on the abundance patterns and can be due to accretion of gas induced by the bar. Our results exclude an important infall event as a trigger for the last starburst., 10 pages, 8 figures, accepted for publication in MNRAS
Published: 2015

70. Spectro-photometric distances to stars: a general-purpose Bayesian approach

Author: Luiz N. da Costa, Anna B. A. Queiroz, Timothy C. Beers, Mathias Schultheis, Basilio X. Santiago, Donald P. Schneider, Léo Girardi, Helio J. Rocha-Pinto, Friedrich Anders, Young Sun Lee, Gail Zasowski, Cristina Chiappini, Marcio A. G. Maia, Josefina Montalbán, Matthias Steinmetz, Peter M. Frinchaboy, Dorothée Brauer, Andrea Miglio, and Eduardo Balbinot
Subjects: Red giant, FOS: Physical sciences, Probability density function, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Segue, Giant star, Astrophysics - Astrophysics of Galaxies, Stars, Star cluster, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Globular cluster, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Parallax
Abstract: We developed a code that estimates distances to stars using measured spectroscopic and photometric quantities. We employ a Bayesian approach to build the probability distribution function over stellar evolutionary models given these data, delivering estimates of model parameters for each star individually. The code was first tested on simulations, successfully recovering input distances to mock stars with, 30 pages, 9 figures. Approved for publication
Published: 2015
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71. The Gaia -ESO Survey: Tracing interstellar extinction

Author: P. Francois, Gerard Gilmore, P. de Laverny, Carmela Lardo, Sofia Feltzing, Ettore Flaccomio, Georges Kordopatis, Paula Jofre, A. C. Lanzafame, Simone Zaggia, L. Prisinzano, Mathias Schultheis, Vanessa Hill, C. C. Worley, Emilio J. Alfaro, Alejandra Recio-Blanco, A. Hourihane, Francesco Damiani, F. M. Jiménez-Esteban, M. T. Costado, L. Morbidelli, Thomas Bensby, Schultheis M., Kordopatis G., Recio-Blanco A., De Laverny P., Hill V., Gilmore G., Alfaro E.J., Costado M.T., Bensby T., Damiani F., Feltzing S., Flaccomio E., Lardo C., Jofre P., Prisinzano L., Zaggia S., Jimenez-Esteban F., Morbidelli L., Lanzafame A.C., Hourihane A., Worley C., Francois P., Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), 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 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), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 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, 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), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), University of Turin, Lund Observatory, Lund University [Lund], Ecole Polytechnique Fédérale de Lausanne (EPFL), INAF - Osservatorio Astrofisico di Catania (OACT), Istituto Nazionale di Astrofisica (INAF), Institut de Mécanique des Fluides et des Solides (IMFS), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Computation, Extinction (astronomy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Tracing, 01 natural sciences, Photometry (optics), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Galaxy: structure, Astrophysics::Galaxy Astrophysics, Dust, extinction, Physics, [PHYS]Physics [physics], Galaxy: stellar content, 010308 nuclear & particles physics, extinction, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Molar absorptivity, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy: structure, dust, extinction, Galaxy: stellar content, dust, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Data release
Abstract: Large spectroscopic surveys have enabled in the recent years the computation of three-dimensional interstellar extinction maps thanks to accurate stellar atmospheric parameters and line-of-sight distances. Such maps are complementary to 3D maps extracted from photometry, allowing a more thorough study of the dust properties. Our goal is to use the high-resolution spectroscopic survey Gaia-ESO in order to obtain with a good distance resolution the interstellar extinction and its dependency as a function of the environment and the Galactocentric position. We use the stellar atmospheric parameters of more than 5000 stars, obtained from the Gaia-ESO survey second internal data release, and combine them with optical (SDSS) and near-infrared (VISTA) photometry as well as different sets of theoretical stellar isochrones, in order to calculate line-of-sight extinction and distances. The extinction coefficients are then compared with the literature to discuss their dependancy on the stellar parameters and position in the Galaxy. Within the errors of our method, our work does not show that there is any dependence of the interstellar extinction coefficient on the atmospheric parameters of the stars. We do not find any evidence of the variation of E(J-H)/E(J-K) with the angle from the Galactic centre nor with Galactocentric distance. This suggests that we are dealing with a uniform extinction law in the SDSS ugriz bands and the near-IR JHKs bands. Therefore, extinction maps using mean colour-excesses and assuming a constant extinction coefficient can be used without introducing any systematic errors., Comment: 13 pages, 14 figures, 1 Appendix accepted for publication in Astronomy&Astrophysics
Published: 2015

72. Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk

Author: Jonathan C. Bird, Timothy C. Beers, Steven R. Majewski, Michael F. Skrutskie, Gail Zasowski, Kaike Pan, Paul Harding, David H. Weinberg, Robert W. O'Connell, Jon A. Holtzman, Mathias Schultheis, Ivan Minchev, Matthias Steinmetz, Cristina Chiappini, Michael R. Hayden, Léo Girardi, Friedrich Anders, D. A. García-Hernández, Brett H. Andrews, Ana E. García Pérez, Carlos Allende Prieto, Jennifer A. Johnson, David L. Nidever, Fred Hearty, Matthew Shetrone, Dmitry Bizyaev, Peter M. Frinchaboy, Annie C. Robin, Verne V. Smith, Jo Bovy, Olga Zamora, Donald P. Schneider, Ricardo P. Schiavon, Szabolcs Mészáros, Katia Cunha, John C. Wilson, 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 Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and 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)
Subjects: Milky Way, Metallicity, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Galaxy: disk, 0103 physical sciences, Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, Disc, 010303 astronomy & astrophysics, Galaxy: structure, Astrophysics::Galaxy Astrophysics, QB, Physics, Galaxy: evolution, Galaxy: stellar content, 010308 nuclear & particles physics, Track (disk drive), Astronomy and Astrophysics, Radius, Astrophysics - Astrophysics of Galaxies, Stars, Distribution function, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Using a sample of 69,919 red giants from the SDSS-III/APOGEE Data Release 12, we measure the distribution of stars in the [$\alpha$/Fe] vs. [Fe/H] plane and the metallicity distribution functions (MDF) across an unprecedented volume of the Milky Way disk, with radius $311$ kpc. The peak of the midplane MDF shifts to lower metallicity at larger $R$, reflecting the Galactic metallicity gradient. Most strikingly, the shape of the midplane MDF changes systematically with radius, with a negatively skewed distribution at $31$ kpc or [$\alpha$/Fe]$>0.18$, the MDF shows little dependence on $R$. The positive skewness of the outer disk MDF may be a signature of radial migration; we show that blurring of stellar populations by orbital eccentricities is not enough to explain the reversal of MDF shape but a simple model of radial migration can do so., Comment: Submitted, 18 pages, 16 figures
Published: 2015

73. Chemical abundances of M giants in the Galactic centre: A single metal-rich population with low [alpha/Fe]

Author: Mathias Schultheis and Nils Ryde
Subjects: Milky Way, Metallicity, Population, Extinction (astronomy), bulge [Galaxy], FOS: Physical sciences, Context (language use), Astrophysics, Bulge, Astronomy, Astrophysics and Cosmology, stellar content [Galaxy], [stars], education, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, stars [infrared], Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, abundances [stars], Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Supergiant, structure [Galaxy], fundamental parameters
Abstract: Context. The formation and evolution of the Milky Way bulge is still largely an unanswered question. One of the most essential observables needed in its modelling are the metallicity distribution and the trends of the alpha elements as measured in stars. While Bulge regions beyond R > 50 pc of the centre has been targeted in several surveys, the central part has escaped detailed study due to the extreme extinction and crowding. The abundance gradients from the center are, however, of large diagnostic value. Aims. We aim at investigating the Galactic Centre environment by probing M giants in the field, avoiding supergiants and cluster members. Methods. For 9 field M-giants in the Galactic Centre region, we have obtained high- and low-resolution spectra observed simultaneously with CRIRES and ISAAC on UT1 and UT3 of the VLT. The low-resolution spectra provide a means of determining the effective temperatures, and the high-resolution spectra provide detailed abundances of Fe, Mg, Si, and Ca. Results. We find a metal-rich population at [Fe/H]=+0.11+-0.15 and a lack of the metal-poor population, found further out in the Bulge, corroborating earlier studies. Our [alpha/Fe] element trends, however, show low values, following the outer Bulge trends. A possible exception of the [Ca/Fe] trend is found and needs further investigation. Conclusions. The results of the analysed field M-giants in the Galactic Centre region, excludes a scenario with rapid formation, in which SNIIe played a dominated role in the chemical enrichment of the gas. The metal-rich metallicities together with low alpha-enhancement seems to indicate a bar-like population perhaps related to the nuclear bar., Accepted for publication in A&A
Published: 2015

74. Recent star formation in the inner Galactic Bulge seen by ISOGAL

Author: Mathias Schultheis, Frederic Schuller, Ian S. Glass, Stephan D. Price, Alain Omont, and Michael P. Egan
Subjects: Physics, education.field_of_study, Star formation, Young stellar object, Astrophysics (astro-ph), Population, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Galaxy, Photometry (astronomy), Stars, Space and Planetary Science, Bulge, education
Abstract: Context: The stellar populations in the central region of the Galaxy are poorly known because of the high visual extinction and very great source density in this direction. Aims: To use recent infrared surveys for studying the dusty stellar objects in this region. Methods: We analyse the content of a 20x20 arcmin^2 field centred at (l,b)=(-0.27,-0.06) observed at 7 and 15 microns as part of the ISOGAL survey. These ISO observations are more than an order of magnitude better in sensitivity and spatial resolution than the IRAS observations. The sources are cross-associated with other catalogues to identify various types of objects. We then derive criteria to distinguish young objects from post-main sequence stars. Results: We find that a sample of about 50 young stellar objects and ultra-compact HII regions emerges, out of a population of evolved AGB stars. We demonstrate that the sources colours and spatial extents, as they appear in the ISOGAL catalogue, possibly complemented with MSX photometry at 21 microns, can be used to determine whether the ISOGAL sources brighter than 300 mJy at 15 microns (or [15] < 4.5 mag) are young objects or late-type evolved stars., 15 pages, 12 figures. Accepted for publication in Astronomy and Astrophysics
Published: 2006

75. Stellar populations in the CFHTLS

Author: Mathias Schultheis, Annie C. Robin, Emmanuel Bertin, Céline Reylé, Yannick Mellier, H. J. McCracken, O. Le Fèvre, Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: stars: luminosity function, Brown dwarf, FOS: Physical sciences, Photometric system, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], stars: atmospheres, stars: low mass, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Galaxy: stellar content, stars: white dwarfs, Astrophysics (astro-ph), Stellar atmosphere, White dwarf, Astronomy and Astrophysics, Quasar, Galaxy, Stars, binaries: general, mass function, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Low Mass, brown dwarfs
Abstract: We present a stellar populations analysis of the first release of the CFHTLS (Canada-France-Hawai Telescope Legacy Survey) data. A detailed comparison between the Besan\c{c}on model of the Galaxy and the first data release of the CFHTLS-Deep survey is performed by implementing the MEGACAM photometric system in this model using stellar atmosphere model libraries. The reliability of the theoretical libraries to reproduce the observed colours in the MEGACAM system is investigated. The locations of various stellar species like subdwarfs, white dwarfs, late-type and brown dwarfs, binary systems are identified. The contamination of the stellar sample by quasars and compact galaxies is quantified using spectroscopic data from the VIMOS-VLT Deep Survey (VVDS) as a function of $i'$ magnitude and $r'-i'$ colour. A comparison between simulated counts using the standard IMF at low masses show that the number of very low mass dwarfs may have been underestimated in previous studies. These observations favour a power law IMF following $d(n)/dm \propto m^{-\alpha}$ with $\alpha=2.5$ for $m < $ 0.25 \Msun or $\alpha=3.0$ for $m < $ 0.2 \Msun for single stars. The resulting LF is in agreement with the local LF as measured from the 5 or 25 pc samples. It is in strong disagreement with the Zheng et al (2001) LF measured from deep HST data. We show that this discrepancy can be understood as an indication of a different IMF at low masses at early epochs of the Galaxy compared to the local thin disc IMF., Comment: 15 pages The original paper with the figures at high resolution can be found under the anonymous ftp (ftp.iap.fr: pub/from_users/schulthe/cfhtls.pdf)
Published: 2006

76. FLUORINE IN THE SOLAR NEIGHBORHOOD: NO EVIDENCE FOR THE NEUTRINO PROCESS

Author: Henrik Jönsson, Verne V. Smith, Mathias Schultheis, Katia Cunha, Francesca Matteucci, E. Spitoni, Kenneth H. Hinkle, Nils Ryde, Observatoire de la Côte d'Azur (OCA), Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur ( OCA ), Centre National de la Recherche Scientifique ( CNRS ), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Jönsson, H., Ryde, N., Spitoni, Emanuele, Matteucci, MARIA FRANCESCA, Cunha, K., Smith, V., Hinkle, K., and Schultheis, M.
Subjects: stars: abundances, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], FOS: Physical sciences, chemistry.chemical_element, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, abundance [stars], 01 natural sciences, Spectral line, Abundance (ecology), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, abundance [Galaxy], Physics::Chemical Physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Galaxy: abundances, solar neighborhood, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics::Galaxy Astrophysics, Physics, Molecular line, 010308 nuclear & particles physics, Astronomy and Astrophysic, Astrophysics - Astrophysics of Galaxies, Stars, Supernova, Astrophysics - Solar and Stellar Astrophysics, chemistry, Astrophysics of Galaxies (astro-ph.GA), Fluorine, Astrophysics::Earth and Planetary Astrophysics, Neutrino, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Asymptotic Giant Branch stars are known to produce `cosmic' fluorine but it is uncertain whether these stars are the main producers of fluorine in the Solar neighborhood or if any of the other proposed formation sites, type II supernovae and/or Wolf-Rayet stars, are more important. Recent articles have proposed both Asymptotic Giant Branch stars as well as type II supernovae as the dominant sources of fluorine in the Solar neighborhood. In this paper we set out to determine the fluorine abundance in a sample of 49 nearby, bright K-giants for which we previously have determined the stellar parameters as well as alpha abundances homogeneously from optical high-resolution spectra. The fluorine abundance is determined from a 2.3 $\mu$m HF molecular line observed with the spectrometer Phoenix. We compare the fluorine abundances with those of alpha elements mainly produced in type II supernovae and find that fluorine and the alpha-elements do not evolve in lock-step, ruling out type II supernovae as the dominating producers of fluorine in the Solar neighborhood. Furthermore, we find a secondary behavior of fluorine with respect to oxygen, which is another evidence against the type II supernovae playing a large role in the production of fluorine in the Solar neighborhood. This secondary behavior of fluorine will put new constraints on stellar models of the other two suggested production sites: Asymptotic Giant Branch stars and Wolf-Rayet stars., Comment: Accepted for publication in ApJ
Published: 2017

77. Milky Way demographics with the VVV Survey III. Evidence for a Great Dark Lane in the 157 Million Star Bulge Color-Magnitude Diagram

Author: Marina Rejkuba, Mathias Schultheis, Jim Emerson, Robert A. Benjamin, Roberto K. Saito, Javier Alonso-García, Márcio Catelan, I. Dékány, Maren Hempel, Oscar A. Gonzalez, Dante Minniti, Manuela Zoccali, and Philip W. Lucas
Subjects: Physics, 010308 nuclear & particles physics, Red giant, Milky Way, Extinction (astronomy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Dust lane, Stars, Space and Planetary Science, Bulge, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The new generation of IR surveys are revealing and quantifying Galactic features, providing an improved 3-D interpretation of our own Galaxy. We present an analysis of the global distribution of dust clouds in the bulge using the near-IR photometry of 157 million stars from the VVV Survey. We investigate the color magnitude diagram of the Milky Way bulge which shows a red giant clump of core He burning stars that is split in two color components, with a mean color difference of (Z-Ks)=0.55 magnitudes equivalent to A_V=2.0 magnitudes. We conclude that there is an optically thick dust lane at intermediate latitudes above and below the plane, that runs across several square degrees from l=-10 deg to l=+10 deg. We call this feature the "Great Dark Lane". Although its exact distance is uncertain, it is located in front of the bulge. The evidence for a large-scale great dark lane within the Galactic bulge is important in order to constrain models of the barred Milky Way bulge and to compare our galaxy with external barred galaxies, where these kinds of features are prominent. We discuss two other potential implications of the presence of the Great Dark Lane for microlensing and bulge stellar populations studies., 5 pages, 4 figures, accepted for publication in Astronomy and Astrophysics
Published: 2014

78. The Gaia -ESO Survey: Metallicity and kinematic trends in the Milky Way bulge

Author: Mathias Schultheis, Emilio J. Alfaro, C. Babusiaux, Dante Minniti, R. F. G. Wyse, A. C. Lanzafame, L. Morbidelli, Manuela Zoccali, Francesco Damiani, Enrico Maiorca, Rodolfo Smiljanic, Sofia Randich, Gerard Gilmore, Alejandra Recio-Blanco, P. de Laverny, Maria Bergemann, Clare Worley, Laura Magrini, Carmela Lardo, Ettore Flaccomio, Luca Sbordone, Sofia Feltzing, A. Hourihane, Oscar A. Gonzalez, Angela Bragaglia, Simone Zaggia, Vanessa Hill, Paula Jofre, Antonella Vallenari, A. Rojas-Arriagada, Thomas Bensby, M. T. Costado, Elena Pancino, Rojas-Arriagada A., Recio-Blanco A., Hill V., De Laverny P., Schultheis M., Babusiaux C., Zoccali M., Minniti D., Gonzalez O.A., Feltzing S., Gilmore G., Randich S., Vallenari A., Alfaro E.J., Bensby T., Bragaglia A., Flaccomio E., Lanzafame A.C., Pancino E., Smiljanic R., Bergemann M., Costado M.T., Damiani F., Hourihane A., Jofre P., Lardo C., Magrini L., Maiorca E., Morbidelli L., Sbordone L., Worley C.C., Zaggia S., Wyse R., Pontificia Universidad Católica de Chile (UC), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 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), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Universidad Andrés Bello [Santiago] (UNAB), Lund Observatory, Lund University [Lund], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), INAF - Osservatorio Astronomico di Bologna (OABO), INAF - Osservatorio Astrofisico di Catania (OACT), Polish Academy of Sciences (PAN), University of Turin, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), INAF - Osservatorio Astrofisico di Arcetri (OAA), and 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)
Subjects: Vista Variables in the Via Lactea, Milky Way, Metallicity, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy: bulge, Bulge, education, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, [PHYS]Physics [physics], Physics, education.field_of_study, Galaxy: stellar content, Stars: abundances, Velocity dispersion, Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Galaxy: abundance, Stars, Space and Planetary Science, Galaxy: formation, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: (Abridged) We analyzed the stellar parameters and radial velocities of ~1200 stars in five bulge fields as determined from the Gaia-ESO survey data (iDR1). We use VISTA Variables in The Via Lactea (VVV) photometry to obtain reddening values by using a semi-empirical T_eff-color calibration. From a Gaussian decomposition of the metallicity distribution functions, we unveil a clear bimodality in all fields, with the relative size of components depending of the specific position on the sky. In agreement with some previous studies, we find a mild gradient along the minor axis (-0.05 dex/deg between b=-6 and b=-10) that arises from the varying proportion of metal-rich and metal-poor components. The number of metal-rich stars fades in favor of the metal-poor stars with increasing b. The K-magnitude distribution of the metal-rich population splits into two peaks for two of the analyzed fields that intersects the near and far branches of the X-shaped bulge structure. In addition, two lateral fields at (l,b)=(7,-9) and (l,b)=(-10,-8) present contrasting characteristics. In the former, the metallicity distribution is dominated by metal-rich stars, while in the latter it presents a mix of a metal-poor population and and a metal-intermediate one, of nearly equal sizes. Finally, we find systematic differences in the velocity dispersion between the metal-rich and the metal-poor components of each field. Our chemo-kinematical analysis is consistent with a varying field-to-field proportion of stars belonging to (i) a metal-rich boxy/peanut X-shaped component, with bar-like kinematics, and (ii) a metal-poor more extended rotating structure with a higher velocity dispersion that dominates far from the Galactic plane. These first GES data allow studying the detailed spatial dependence of the Galactic bulge populations, thanks to the analysis of individual fields with relatively high statistics., Accepted for publication in Astronomy and Astrophysics
Published: 2014

79. Discovery of possible molecular counterparts to the infrared double helix nebula in the galactic center

Author: Mathias Schultheis, Norikazu Mizuno, Ryoji Matsumoto, Ryuji Okamoto, Eri Furuhashi, Naoko Furukawa, T. Okuda, Yuta Asahina, N. Hanaoka, Atsushi Nishimura, Hiroaki Yamamoto, T. Hayakawa, Akio Ohama, Kazuhito Dobashi, Mark Morris, Toshikazu Onishi, Satoshi Yoshiike, Y. Mori, Akiko Kawamura, Rei Enokiya, Kouji Nakamura, N. Moribe, Hidetoshi Sano, J. Sato, Yasuo Fukui, and Kazufumi Torii
Subjects: astro-ph.SR, Helix Nebula, Infrared, astro-ph.GA, Extinction (astronomy), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astronomy & Astrophysics, Atomic, Physical Chemistry, Particle and Plasma Physics, ISM [radio lines], K band, Nuclear, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, geography, geography.geographical_feature_category, Galactic Center, Molecular, Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, 85-05, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Ridge, Astrophysics of Galaxies (astro-ph.GA), clouds [ISM], Astronomical and Space Sciences, Physical Chemistry (incl. Structural)
Abstract: We have discovered two molecular features at radial velocities of -35 km/s and 0 km/s toward the infrared Double Helix Nebula (DHN) in the Galactic center with NANTEN2. The two features show good spatial correspondence with the DHN. We have also found two elongated molecular ridges at these two velocities distributed vertically to the Galactic plane over 0.8 degree. The two ridges are linked by broad features in velocity and are likely connected physically with each other. The ratio between the 12CO J=2-1 and J=1-0 transitions is 0.8 in the ridges which is larger than the average value 0.5 in the foreground gas, suggesting the two ridges are in the Galactic center. An examination of the K band extinction reveals a good coincidence with the CO 0 km/s ridge and is consistent with a distance of 8 +/-2 kpc. We discuss the possibility that the DHN was created by a magnetic phenomenon incorporating torsional Alfv��n waves launched from the circumnuclear disk (Morris, Uchida & Do 2006) and present a first estimate of the mass and energy involved in the DHN., 32 pages, 23 figures, Accepted by ApJ
Published: 2014

80. The APOGEE red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk

Author: David L. Nidever, Hans-Walter Rix, Audrey Simmons, Marc H. Pinsonneault, Dmitry Bizyaev, Donald P. Schneider, Rafael A. García, L. Koesterke, Jennifer A. Johnson, John C. Wilson, Gail Zasowski, Peter M. Frinchaboy, Saskia Hekker, William J. Chaplin, Verne V. Smith, Léo Girardi, Robert W. O'Connell, Katia Cunha, Sarbani Basu, Keivan G. Stassun, Aldo Serenelli, Steven R. Majewski, Olga Zamora, D. A. García-Hernández, Jon A. Holtzman, Thomas Kallinger, Matthew Shetrone, Annie C. Robin, Kaike Pan, Carlos Allende Prieto, Szabolcs Mészáros, Benoit Mosser, Ana G. Pérez, Brett H. Andrews, Daniel Oravetz, Fred R. Hearty, David H. Weinberg, Michael F. Skrutskie, Dennis Stello, Thaíse S. Rodrigues, Ricardo P. Schiavon, Mathias Schultheis, Courtney R. Epstein, Adam Burton, Michael R. Hayden, S. Drew Chojnowski, Timothy C. Beers, Karen Kinemuchi, Yvonne Elsworth, Victor Silva Aguirre, Jo Bovy, 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), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, J. A. Baker Institute, Cornell University [New York], Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Stellar Astrophysics Centre [Aarhus] (SAC), Aarhus University [Aarhus], National University of Singapore (NUS), Department of Psychology, St John's University, School of Physics and Astronomy, University of Birmingham [Birmingham], Research institute of Computer Vision and Robotics [Girona] (VICOROB), Universitat de Girona (UdG), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pennsylvania State University (Penn State), Penn State System, 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), Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), Max-Planck-Institut für Astrophysik (MPA), Vanderbilt University [Nashville], World Bank, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and 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)
Subjects: Proper motion, Metallicity, Milky Way, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Asteroseismology, Galaxy: disk, Bulge, 0103 physical sciences, distances [stars], stellar content [Galaxy], Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Red clump, Galaxy: structure, stars: general, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Physics, [PHYS]Physics [physics], Galaxy: stellar content, 010308 nuclear & particles physics, general [stars], Astrophysics::Instrumentation and Methods for Astrophysics, abundances [Galaxy], Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), stars: distances, Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], disk [Galaxy], structure [Galaxy]
Abstract: International audience; The Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution near-infrared spectroscopic survey covering all of the major components of the Galaxy, including the dust-obscured regions of the inner Milky Way disk and bulge. Here we present a sample of 10,341 likely red-clump stars (RC) from the first two years of APOGEE operations, selected based on their position in color–metallicity–surface-gravity–effective-temperature space using a new method calibrated using stellar evolution models and high-quality asteroseismology data. The narrowness of the RC locus in color–metallicity–luminosity space allows us to assign distances to the stars with an accuracy of 5%–10%. The sample extends to typical distances of about 3 kpc from the Sun, with some stars out to 8 kpc, and spans a volume of approximately 100 kpc3 over 5 kpc ≲ R ≲ 14 kpc, |Z| ≲ 2 kpc, and −15° ≲ Galactocentric azimuth ≲ 30°. The APOGEE red-clump (APOGEE-RC) catalog contains photometry from the Two Micron All Sky Survey, reddening estimates, distances, line-of-sight velocities, stellar parameters and elemental abundances determined from the high-resolution APOGEE spectra, and matches to major proper motion catalogs. We determine the survey selection function for this data set and discuss how the RC selection samples the underlying stellar populations. We use this sample to limit any azimuthal variations in the median metallicity within the ≈45° azimuthal region covered by the current sample to be ⩽0.02 dex, which is more than an order of magnitude smaller than the radial metallicity gradient. This result constrains coherent non-axisymmetric flows within a few kiloparsecs from the Sun.
Published: 2014

81. Chemodynamics of the Milky Way. I. The first year of APOGEE data

Author: Michael R. Hayden, Timothy C. Beers, Helio J. Rocha-Pinto, Jennifer E. Johnson, Jon A. Holtzman, Matthew Shetrone, M. A. G. Maia, Ricardo P. Schiavon, Ivan Minchev, Cristina Chiappini, Steve Majewski, Viktor Malanushenko, Karen Kinemuchi, A. E. Garcia Perez, Peter M. Frinchaboy, Annie C. Robin, Eduardo Balbinot, C. Allende Prieto, D. Bizyaev, Keivan G. Stassun, Kaike Pan, Friedrich Anders, Gail Zasowski, David L. Nidever, Katia Cunha, Léo Girardi, Andrea Miglio, Corrado Boeche, Frederick R. Hearty, J. Brinkmann, Donald P. Schneider, Mike Skrutskie, Matthias Steinmetz, L. N. da Costa, Dorothée Brauer, Verne V. Smith, Basilio X. Santiago, Josefina Montalbán, Elena Malanushenko, Robert W. O'Connell, Mathias Schultheis, Leibniz-Institut für Astrophysik Potsdam (AIP), Technische Universität Dresden = Dresden University of Technology (TU Dresden), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Apache point observatory, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), and 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)
Subjects: stars: abundances, Red giant, Milky Way, Metallicity, stars: kinematics and dynamics, FOS: Physical sciences, Astrophysics, Galaxia, Astrophysics::Cosmology and Extragalactic Astrophysics, evolution [Galaxy], Galaxy: disk, Observatory, Astrophysics::Solar and Stellar Astrophysics, Cinemática, kinematics and dynamics [Stars], Galaxy: general, general [Galaxy], Astrophysics::Galaxy Astrophysics, Physics, Orbital elements, Galaxy: evolution, abundances [Galaxy], Astronomy and Astrophysics, Segue, Astrophysics - Astrophysics of Galaxies, Stars, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), abundances [Stars], Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], disk [Galaxy]
Abstract: We investigate the chemo-kinematic properties of the Milky Way disc by exploring the first year of data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), and compare our results to smaller optical high-resolution samples in the literature, as well as results from lower resolution surveys such as GCS, SEGUE and RAVE. We start by selecting a high-quality sample in terms of chemistry ($\sim$ 20.000 stars) and, after computing distances and orbital parameters for this sample, we employ a number of useful subsets to formulate constraints on Galactic chemical and chemodynamical evolution processes in the Solar neighbourhood and beyond (e.g., metallicity distributions -- MDFs, [$\alpha$/Fe] vs. [Fe/H] diagrams, and abundance gradients). Our red giant sample spans distances as large as 10 kpc from the Sun. We find remarkable agreement between the recently published local (d $, Comment: 25 pages, 17 figures. A&A, in press
Published: 2013

82. Very Metal-poor Stars in the Outer Galactic Bulge Found by the APOGEE Survey

Author: Verne V. Smith, Jennifer A. Johnson, David L. Nidever, Garrett Ebelke, Carlos Allende Prieto, Szabolcs Mészáros, Peter M. Frinchaboy, Donald P. Schneider, Audrey Simmonsand, Ricardo P. Schiavon, Timothy C. Beers, John C. Wilson, Michael F. Skrutskie, Robert W. O'Connel, Matthew Shetrone, Mathias Schultheis, Annie C. Robin, Daniel J. Eisenstein, Katia Cunha, Viktor Malanushenko, Gail Zasowski, Ana G. Pérez, Fred R. Hearty, Léo Girardi, Jon A. Holtzman, Elena Malanushenko, Dmitry Bizyaev, Daniel Oravetz, Steven R. Majewski, Kaike Pan, Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), 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 Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and 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)
Subjects: 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Milky Way, Metallicity, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Giant star, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Sky, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics
Abstract: Despite its importance for understanding the nature of early stellar generations and for constraining Galactic bulge formation models, at present little is known about the metal-poor stellar content of the central Milky Way. This is a consequence of the great distances involved and intervening dust obscuration, which challenge optical studies. However, the Apache Point Observatory Galactic Evolution Experiment (APOGEE), a wide-area, multifiber, high-resolution spectroscopic survey within Sloan Digital Sky Survey III (SDSS-III), is exploring the chemistry of all Galactic stellar populations at infrared wavelengths, with particular emphasis on the disk and the bulge. An automated spectral analysis of data on 2,403 giant stars in twelve fields in the bulge obtained during APOGEE commissioning yielded five stars with low metallicity([Fe/H]$\le-1.7$), including two that are very metal-poor [Fe/H]$\sim-2.1$ by bulge standards. Luminosity-based distance estimates place the five stars within the outer bulge, where other 1,246 of the analyzed stars may reside. A manual reanalysis of the spectra verifies the low metallicities, and finds these stars to be enhanced in the $\alpha$-elements O, Mg, and Si without significant $\alpha$-pattern differences with other local halo or metal-weak thick-disk stars of similar metallicity, or even with other more metal-rich bulge stars. While neither the kinematics nor chemistry of these stars can yet definitively determine which, if any, are truly bulge members, rather than denizens of other populations co-located with the bulge, the newly-identified stars reveal that the chemistry of metal-poor stars in the central Galaxy resembles that of metal-weak thick-disk stars at similar metallicity., Comment: 6 pages, 3 figures, 2 tables
Published: 2013

83. Three dimensional interstellar extinction map towards the Galactic Bulge

Author: Annie Robin, Mathias Schultheis, Biwei Jiang, Marina Rejkuba, Oscar Gonzalez Lopez, Dante Minniti, Bingqiu Chen, Oscar Gonzalez, 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), Department of Astronomy, Beijing Normal University, China, 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), European Southern Observatory (ESO), Pontificia Universidad Católica de Chile (UC), Specola Vaticana/Vatican Observatory, Université de Franche-Comté (UFC), and 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)
Subjects: Physics, Line-of-sight, 010308 nuclear & particles physics, Extinction (astronomy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Function (mathematics), Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Galaxy, Photometry (optics), Dimension (vector space), Space and Planetary Science, Bulge, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Variation (astronomy), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract: Studies of the properties of the inner Galactic Bulge depend strongly on the assumptions about the interstellar extinction. Most of the extinction maps available in the literature lack the information about the distance. We combine the observations with the Besancon model of the Galaxy to investigate the variations of extinction along different lines of sight towards the inner Galactic bulge as a function of distance. In addition we study the variations in the extinction law in the Bulge. We construct color-magnitude diagrams with the following sets of colors: H-Ks and J-Ks from the VVV catalogue as well as Ks-[3.6], Ks-[4.5], Ks-[5.8] and Ks-[8.0] from GLIMPSE-II catalogue matched with 2MASS. Using the newly derived temperature-color relation for M giants that match better the observed color-magnitude diagrams we then use the distance-color relations to derive the extinction as a function of distance. The observed colors are shifted to match the intrinsic colors in the Besan\c{c}on model, as a function of distance, iteratively thereby creating an extinction map with three dimensions: two spatial and one distance dimension along each line of sight towards the bulge. Colour excess maps are presented at a resolution of 15' x 15' for 6 different combinations of colors, in distance bins of 1 kpc. The high resolution and depth of the photometry allows to derive extinction maps to 10 kpc distance and up to 35 magnitudes of extinction in Av (3.5 mag in Aks). Integrated maps show the same dust features and consistent values with the other 2D maps. Starting from the color excess between the observations and the model we investigate the extinction law in near-infrared and its variation along different lines of sight., Comment: 25 pages, accepted for publication in Astronomy&Astrophysics
Published: 2013

84. Target selection for the Apache Point Observatory Galactic Evolution Experiment (APOGEE)

Author: Mathias Schultheis, Courtney R. Epstein, Scott W. Fleming, Kyle M. Cudworth, Damian Fabbian, D. A. Garcia Hernandez, S. D. Chojnowski, Ryan Terrien, Sz. Meszaros, Léo Girardi, Jon A. Holtzman, Rachael L. Beaton, Jennifer A. Johnson, H. J. Rocha Pinto, Brett H. Andrews, Ricardo P. Schiavon, Steven R. Majewski, Rohit Deshpande, Basilio X. Santiago, Marc H. Pinsonneault, Matthew Shetrone, C. Allende Prieto, Kate Jackson, A. Herrero, Mike Skrutskie, Peter M. Frinchaboy, Gail Zasowski, Sten Hasselquist, Andrew J. Burton, Robert W. O'Connell, David L. Nidever, Cullen H. Blake, Frederick R. Hearty, D. Bizyaev, M. A. G. Maia, Christine O'Donnell, Verne V. Smith, L. N. da Costa, Kevin R. Covey, Jeffrey A. Munn, Katia Cunha, John C. Wilson, A. E. Garcia Perez, Suvrath Mahadevan, J. van Saders, Kris Sellgren, Ohio State University [Columbus] (OSU), University of Virginia [Charlottesville], Texas Christian University (TCU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Princeton University, Department of Astronomy and Astrophysics [PennState], Pennsylvania State University (Penn State), Penn State System-Penn State System, Instituto de Astrofisica de Canarias (IAC), Universidad de La Laguna [Tenerife - SP] (ULL), 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), Apache point observatory, Astrophysics Research Institute [Liverpool] (ARI), Liverpool John Moores University (LJMU), McDonald Observatory, and University of Texas at Austin [Austin]
Subjects: Red giant, Milky Way, Metallicity, Extinction (astronomy), FOS: Physical sciences, Astrophysics, Galaxia, Espectros astronômicos, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, 01 natural sciences, Astronomia infravermelha, surveys, Observatory, Bulge, 0103 physical sciences, Telescópios astronômicos, 010303 astronomy & astrophysics, Tecnicas astronomicas, stars: general, Astrophysics::Galaxy Astrophysics, Physics, Mapeamentos astronômicos, general [Stars], 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, abundances [Galaxy], Astronomy and Astrophysics, kinematics and dynamics [Galaxy], Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Estrelas gigantes, Galaxy: abundances, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Galaxy: kinematics and dynamics
Abstract: The Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution infrared spectroscopic survey spanning all Galactic environments (i.e., bulge, disk, and halo), with the principal goal of constraining dynamical and chemical evolution models of the Milky Way. APOGEE takes advantage of the reduced effects of extinction at infrared wavelengths to observe the inner Galaxy and bulge at an unprecedented level of detail. The survey's broad spatial and wavelength coverage enables users of APOGEE data to address numerous Galactic structure and stellar populations issues. In this paper we describe the APOGEE targeting scheme and document its various target classes to provide the necessary background and reference information to analyze samples of APOGEE data with awareness of the imposed selection criteria and resulting sample properties. APOGEE's primary sample consists of ~100,000 red giant stars, selected to minimize observational biases in age and metallicity. We present the methodology and considerations that drive the selection of this sample and evaluate the accuracy, efficiency, and caveats of the selection and sampling algorithms. We also describe additional target classes that contribute to the APOGEE sample, including numerous ancillary science programs, and we outline the targeting data that will be included in the public data releases., Accepted to AJ. 31 pages, 11 figures
Published: 2013

85. The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

Author: Christopher P. Ahn, Rachael Alexandroff, Carlos Allende Prieto, Scott F. Anderson, Timothy Anderton, Brett H. Andrews, Éric Aubourg, Stephen Bailey, Eduardo Balbinot, Rory Barnes, Julian Bautista, Timothy C. Beers, Alessandra Beifiori, Andreas A. Berlind, Vaishali Bhardwaj, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, John J. Bochanski, Adam S. Bolton, Arnaud Borde, Jo Bovy, W. N. Brandt, J. Brinkmann, Peter J. Brown, Joel R. Brownstein, Kevin Bundy, N. G. Busca, William Carithers, Aurelio R. Carnero, Michael A. Carr, Dana I. Casetti-Dinescu, Yanmei Chen, Cristina Chiappini, Johan Comparat, Natalia Connolly, Justin R. Crepp, Stefano Cristiani, Rupert A. C. Croft, Antonio J. Cuesta, Luiz N. da Costa, James R. A. Davenport, Kyle S. Dawson, Roland de Putter, Nathan De Lee, Timothée Delubac, Saurav Dhital, Anne Ealet, Garrett L. Ebelke, Edward M. Edmondson, Daniel J. Eisenstein, S. Escoffier, Massimiliano Esposito, Michael L. Evans, Xiaohui Fan, Bruno Femenía Castellá, Emma Fernández Alvar, Leticia D. Ferreira, N. Filiz Ak, Hayley Finley, Scott W. Fleming, Andreu Font-Ribera, Peter M. Frinchaboy, D. A. García-Hernández, A. E. García Pérez, Jian Ge, R. Génova-Santos, Bruce A. Gillespie, Léo Girardi, Jonay I. González Hernández, Eva K. Grebel, James E. Gunn, Hong Guo, Daryl Haggard, Jean-Christophe Hamilton, David W. Harris, Suzanne L. Hawley, Frederick R. Hearty, Shirley Ho, David W. Hogg, Jon A. Holtzman, Klaus Honscheid, J. Huehnerhoff, Inese I. Ivans, Željko Ivezić, Heather R. Jacobson, Linhua Jiang, Jonas Johansson, Jennifer A. Johnson, Guinevere Kauffmann, David Kirkby, Jessica A. Kirkpatrick, Mark A. Klaene, Gillian R. Knapp, Jean-Paul Kneib, Jean-Marc Le Goff, Alexie Leauthaud, Khee-Gan Lee, Young Sun Lee, Daniel C. Long, Craig P. Loomis, Sara Lucatello, Britt Lundgren, Robert H. Lupton, Bo Ma, Zhibo Ma, Nicholas MacDonald, Claude E. Mack, Suvrath Mahadevan, Marcio A. G. Maia, Steven R. Majewski, Martin Makler, Elena Malanushenko, Viktor Malanushenko, A. Manchado, Rachel Mandelbaum, Marc Manera, Claudia Maraston, Daniel Margala, Sarah L. Martell, Cameron K. McBride, Ian D. McGreer, Richard G. McMahon, Brice Ménard, Sz. Meszaros, Jordi Miralda-Escudé, Antonio D. Montero-Dorta, Francesco Montesano, Heather L. Morrison, Demitri Muna, Jeffrey A. Munn, Hitoshi Murayama, Adam D. Myers, A. F. Neto, Duy Cuong Nguyen, Robert C. Nichol, David L. Nidever, Pasquier Noterdaeme, Sebastián E. Nuza, Ricardo L. C. Ogando, Matthew D. Olmstead, Daniel J. Oravetz, Russell Owen, Nikhil Padmanabhan, Nathalie Palanque-Delabrouille, Kaike Pan, John K. Parejko, Prachi Parihar, Isabelle Pâris, Petchara Pattarakijwanich, Joshua Pepper, Will J. Percival, Ismael Pérez-Fournon, Ignasi Pérez-Ràfols, Patrick Petitjean, Janine Pforr, Matthew M. Pieri, Marc H. Pinsonneault, G. F. Porto de Mello, Francisco Prada, Adrian M. Price-Whelan, M. Jordan Raddick, Rafael Rebolo, James Rich, Gordon T. Richards, Annie C. Robin, Helio J. Rocha-Pinto, Constance M. Rockosi, Natalie A. Roe, Ashley J. Ross, Nicholas P. Ross, Graziano Rossi, J. A. Rubiño-Martin, Lado Samushia, J. Sanchez Almeida, Ariel G. Sánchez, Basílio Santiago, Conor Sayres, David J. Schlegel, Katharine J. Schlesinger, Sarah J. Schmidt, Donald P. Schneider, Mathias Schultheis, Axel D. Schwope, C. G. Scóccola, Uros Seljak, Erin Sheldon, Yue Shen, Yiping Shu, Jennifer Simmerer, Audrey E. Simmons, Ramin A. Skibba, M. F. Skrutskie, A. Slosar, Flavia Sobreira, Jennifer S. Sobeck, Keivan G. Stassun, Oliver Steele, Matthias Steinmetz, Michael A. Strauss, Alina Streblyanska, Nao Suzuki, Molly E. C. Swanson, Tomer Tal, Aniruddha R. Thakar, Daniel Thomas, Benjamin A. Thompson, Jeremy L. Tinker, Rita Tojeiro, Christy A. Tremonti, M. Vargas Magaña, Licia Verde, Matteo Viel, Shailendra K. Vikas, Nicole P. Vogt, David A. Wake, Ji Wang, Benjamin A. Weaver, David H. Weinberg, Benjamin J. Weiner, Andrew A. West, Martin White, John C. Wilson, John P. Wisniewski, W. M. Wood-Vasey, Brian Yanny, Christophe Yèche, Donald G. York, O. Zamora, Gail Zasowski, Idit Zehavi, Gong-Bo Zhao, Zheng Zheng, Guangtun Zhu, Joel C. Zinn, APC - Cosmologie, 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), AstroParticule et Cosmologie (APC (UMR_7164)), Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), BOSS, Instituto de Astrofisica de Canarias (IAC), 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), Elon University [NC, USA], Department of Astronomy [Seattle], University of Washington [Seattle], The University of Notre Dame [Sydney], Apache point observatory, 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), 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, Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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), 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), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Universitat de Barcelona, Observatoire des Sciences de l'Univers en région Centre (OSUC), and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Atles, Astrophysics, Surveys, 01 natural sciences, Astronomical spectroscopy, Via láctea, Observatory, Observacions astronòmiques, Physical Sciences and Mathematics, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, media_common, Mapeamentos astronômicos, Physics, [PHYS]Physics [physics], Astrophysics::Instrumentation and Methods for Astrophysics, Atlases, Astrometry, Cosmology, atlases, Instrumentation and Methods for Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, Astronomical observations, Cosmology and Gravitation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], media_common.quotation_subject, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, catalogs, surveys, Formacao de galaxias, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), Spectrograph, Astrophysics::Galaxy Astrophysics, Cosmologia, 010308 nuclear & particles physics, Astronomy and Astrophysics, Quasar, Cosmology and Extragalactic Astrophysics, Espectroscòpia, Galaxy, Spectrum analysis, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Stars, Space and Planetary Science, Sky, Catalogs, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014., 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr9
Published: 2012

86. Constraining the structure and formation of the Galactic bulge from a field in its outskirts. FLAMES-GIRAFFE spectra of about 400 red giants around (l,b)=(0{\deg},-10{\deg})

Author: Annie C. Robin, David M. Nataf, Thomas Lebzelter, Mathias Schultheis, Stefan Uttenthaler, Bingqiu Chen, Universität Wien, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut 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 Ohio State University [Columbus] (OSU)
Subjects: stars: abundances, Red giant, Milky Way, Metallicity, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Galaxy: bulge, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Red clump, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, stars: late-type, Velocity dispersion, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Radial velocity, Astrophysics - Solar and Stellar Astrophysics, Galaxy: formation, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Galaxy: kinematics and dynamics
Abstract: The presence of two stellar populations in the Milky Way bulge has been reported recently. We aim at studying the abundances and kinematics of stars in the outer bulge, thereby providing additional constraints on models of its formation. Spectra of 401 red giant stars in a field at (l,b)=(0{\deg},-10{\deg}) were obtained with FLAMES at the VLT. Stars of luminosities down to below the two bulge red clumps (RCs) are included. From these spectra we measure general metallicities, abundances of Fe and the alpha-elements, and radial velocities (RV) of the stars. These measurements as well as photometric data are compared to simulations with the Besancon and TRILEGAL models of the Galaxy. We confirm the presence of two populations among our sample stars: i) a metal-rich one at [M/H] ~+0.3, comprising about 30% of the sample, with low RV dispersion and low alpha-abundance, and ii) a metal-poor population at [M/H] ~-0.6 with high RV dispersion and high alpha-abundance. The metal-rich population could be connected to the Galactic bar. We identify this population as the carrier of the double RC feature. We do not find a significant difference in metallicity or RV between the two RCs, a small difference in metallicity being probably due to a selection effect. The RV dispersion agrees well with predictions of the Besancon Galaxy model, but the metallicity of the "thick bulge" model component should be shifted to lower metallicity by 0.2 to 0.3dex to well reproduce the observations. We present evidence that the metallicity distribution function depends on the evolutionary state of the sample stars, suggesting that enhanced mass loss preferentially removes metal-rich stars. We also confirm the decrease of \alpha-element over-abundance with increasing metallicity., Comment: 19 pages (excluding on-line table), 21 figures, accepted for publication in A&A
Published: 2012

87. The stellar populations of the Milky Way in CFHTLS fields

Author: M. Guittet, Mathias Schultheis, Misha Haywood, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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), C. Reylé, A. Robin and M. Schultheis, and eds.
Subjects: Physics, Milky Way, media_common.quotation_subject, QC1-999, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, law.invention, Telescope, Sky, law, Thick disk, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, media_common
Abstract: International audience; We investigate the characteristics of the thick disk in the Canada – France – Hawaii – Telescope Legacy Survey (CFHTLS) fields, complemented at bright magnitudes with Sloan Digital Sky Survey (SDSS) data. The ([Fe/H], Z) distributions are derived in the W1 and W3 fields, and compared with simulated maps produced using the Besançon model. It is shown that the thick disk, represented in star-count models by a distinct component, is not an adequate description of the observed ([Fe/H], Z) distributions in these fields.
Published: 2012

88. The Apache Point Observatory Galactic Evolution Experiment: First Detection of High Velocity Milky Way Bar Stars

Author: Matthew Shetrone, Mathias Schultheis, Elena Malanushenko, Jon A. Holtzman, Jonathan C. Bird, Rachael L. Beaton, Ricardo P. Schiavon, Annie C. Robin, Steven R. Majewski, Fred R. Hearty, Robert W. O'Connell, Demitri Muna, Ralph Schoenrich, Peter M. Frinchaboy, Kaike Pan, Benjamin J. Weiner, John C. Wilson, Gail Zasowski, Inma Martinez-Valpuesta, Ortwin Gerhard, Howard Brewington, Daniel J. Eisenstein, Carlos Allende Prieto, Audrey Simmons, Viktor Malanushenko, Kris Sellgren, Michael F. Skrutskie, Dmitry Bizyaev, David L. Nidever, Donald P. Schneider, Jennifer A. Johnson, Ana G. Pérez, Jon Brinkmann, Daniel Oravetz, Benjamin A. Weaver, Stephanie A. Snedden, University of Virginia [Charlottesville], Ohio State University [Columbus] (OSU), 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 Extraterrestrische Physik (MPE), McDonald Observatory, University of Texas at Austin [Austin], Gemini Observatory, University of Hawai'i [Hilo], Instituto de Astrofisica de Canarias (IAC), Apache point observatory, Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Texas Christian University (TCU), New Mexico State University, New York University [New York] (NYU), and NYU System (NYU)
Subjects: 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Milky Way, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Observatory, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Physics, Galactic Center, Astronomy and Astrophysics, Giant star, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Commissioning observations with the Apache Point Observatory Galactic Evolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III, have produced radial velocities (RVs) for ~4700 K/M-giant stars in the Milky Way bulge. These high-resolution (R \sim 22,500), high-S/N (>100 per resolution element), near-infrared (1.51-1.70 um; NIR) spectra provide accurate RVs (epsilon_v~0.2 km/s) for the sample of stars in 18 Galactic bulge fields spanning -1-32 deg. This represents the largest NIR high-resolution spectroscopic sample of giant stars ever assembled in this region of the Galaxy. A cold (sigma_v~30 km/s), high-velocity peak (V_GSR \sim +200 km/s) is found to comprise a significant fraction (~10%) of stars in many of these fields. These high RVs have not been detected in previous MW surveys and are not expected for a simple, circularly rotating disk. Preliminary distance estimates rule out an origin from the background Sagittarius tidal stream or a new stream in the MW disk. Comparison to various Galactic models suggests that these high RVs are best explained by stars in orbits of the Galactic bar potential, although some observational features remain unexplained., Comment: 7 pages, 4 figures, accepted for publication in ApJ Letters
Published: 2012
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89. The Besançon Model of Stellar Population Synthesis of the Galaxy

Author: Mathias Schultheis, Douglas J. Marshall, Céline Reylé, Annie C. Robin, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de 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), and 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)
Subjects: Physics, Stellar population, Scale (ratio), 010308 nuclear & particles physics, Bar (music), Extinction (astronomy), Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Galactic plane, 01 natural sciences, Dust lane, Galaxy, Bulge, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 10. No inequality, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract: We present the most recent developments of the Besancon Galaxy model and results obtained from analysis of near-infrared large scale surveys and a new 3D map of the extinction. Giants are the main tracers and are used to characterized the large scale structures in the outer disc and in the inner regions. The warp has been found to be asymmetric and weaker than the HI warp. In the central region, the dust lanes associated with the bar have been detected, characterized and compared with the dust lanes in CO. The nuclear bar is also detected. An improved model of the bulge/bar has been established and the discovery of an in-plane overdensity which could be interpreted as either a second long thin bar, or a merger residual.
Published: 2012

90. CHEMICAL EVOLUTION OF THE INNER 2 DEGREES OF THE MILKY WAY BULGE: [α/Fe] TRENDS AND METALLICITY GRADIENTS

Author: S. Uttenthaler, Mathias Schultheis, V. Grieco, R. M. Rich, Francesca Matteucci, Nils Ryde, Ryde, N., Schultheis, M, Grieco, V., Matteucci, MARIA FRANCESCA, Rich, R. M., and Uttenthaler, S.
Subjects: stars: abundances, Milky Way, Metallicity, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy: bulge, Bulge, 0103 physical sciences, Galaxy: structure, infrared: stars, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Galaxy: stellar content, bulge, Galaxy: stellar content, Galaxy: structure, infrared: stars, stars: abundances, stars: fundamental parameters [Galaxy], 010308 nuclear & particles physics, Star formation, Galactic Center, Astronomy and Astrophysics, Effective temperature, Galactic plane, Astrophysics - Astrophysics of Galaxies, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), stars: fundamental parameters, Galaxy: bulge, Galaxy: stellar content, Galaxy: structure, infrared: stars, stars: abundances, stars: fundamental parameters
Abstract: The structure, formation, and evolution of the Milky Way bulge is a matter of debate. Important diagnostics for discriminating between bulge models include alpha-abundance trends with metallicity, and spatial abundance and metallicity gradients. Due to the severe optical extinction in the inner Bulge region, only a few detailed investigations have been performed of this region. Here we aim at investigating the inner 2 degrees by observing the [alpha/Fe] element trends versus metallicity, and by trying to derive the metallicity gradient. [alpha/Fe] and metallicities have been determined by spectral synthesis of 2 micron spectra observed with VLT/CRIRES of 28 M-giants, lying along the Southern minor axis at (l,b)=(0,0), (0,-1), and (0,-2). VLT/ISAAC spectra are used to determine the effective temperature of the stars. We present the first connection between the Galactic Center and the Bulge using similar stars, high spectral resolution, and analysis techniques. The [alpha/Fe] trends in all our 3 fields show a large similarity among each other and with trends further out in the Bulge, with a lack of an [\alpha/Fe] gradient all the way into the centre. This suggests a homogeneous Bulge when it comes to the enrichment process and star-formation history. We find a large range of metallicities (-1.2, Comment: Accepted for publication in AJ
Published: 2015

91. Lithium abundances along the RGB: FLAMES-GIRAFFE spectra of a large sample of low-mass Bulge stars

Author: Thomas LebzelterUniversity of Vienna, Department of Astronomy, Austria, Stefan Uttenthaler(University of Vienna, Department of Astronomy, Austria), Maurizio Busso(Dipartimento di Fisica, Università di Perugia, and INFN, Sezione di Perugia, Perugia, Italy), Mathias Schultheis(Observatoire de Besançon, Besançon, France), and Bernhard Aringer(INAF - Padova Astronomical Observatory, Padova, Italy)
Subjects: astro-ph.SR, Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Context: A small number of K-type giants on the red giant branch (RGB) is known to be very rich in lithium (Li). This fact is not accounted for by standard stellar evolution theory. The exact phase and mechanism of Li enrichment is still a matter of debate. Aims: Our goal is to probe the abundance of Li along the RGB, from its base to the tip, to confine Li-rich phases that are supposed to occur on the RGB. Methods: For this end, we obtained medium-resolution spectra with the FLAMES spectrograph at the VLT in GIRAFFE mode for a large sample of 401 low-mass RGB stars located in the Galactic bulge. The Li abundance was measured in the stars with a detectable Li 670.8 nm line by means of spectral synthesis with COMARCS model atmospheres. A new 2MASS (J-K) - Teff calibration from COMARCS models is presented in the Appendix. Results: Thirty-one stars with a detectable Li line were identified, three of which are Li-rich according to the usual criterion ($\log\epsilon({\rm Li})>1.5$). The stars are distributed all along the RGB, not concentrated in any particular phase of the red giant evolution (e.g. the luminosity bump or the red clump). The three Li-rich stars are clearly brighter than the luminosity bump and red clump, and do not show any signs of enhanced mass loss. Conclusions: We conclude that the Li enrichment mechanism cannot be restricted to a clearly defined phase of the RGB evolution of low-mass stars ($M\sim1M_{\sun}$), contrary to earlier suggestions from disk field stars., Comment: 6 pages (14 with appendix), 5 figures (1 in appendix), accepted for publication in A&A
Published: 2011
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92. The metallicity distribution of bulge clump giants in Baade's window

Author: Mathias Schultheis, C. Babusiaux, A. E. Gomez, Frédéric Arenou, Manuela Zoccali, Dante Minniti, A. Lecureur, F. Royer, Beatriz Barbuy, Sergio Ortolani, Vanessa Hill, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 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, 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), 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), Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo] (IAG), Universidade de São Paulo (USP), and Universita di Padova
Subjects: 010504 meteorology & atmospheric sciences, Metallicity, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, ESTRELAS, 01 natural sciences, Baade's Window, Spectral line, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Red clump, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], education.field_of_study, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Bar (unit)
Abstract: We seek to constrain the formation of the Galactic bulge by means of analysing the detailed chemical composition of a large sample of red clump stars in Baade's window. We measure [Fe/H] in a sample of 219 bulge red clump stars from R=20000 resolution spectra obtained with FLAMES/GIRAFFE at the VLT, using an automatic procedure, differentially to the metal-rich local reference star muLeo. For a subsample of 162 stars, we also derive [Mg/H] from spectral synthesis around the MgI triplet at 6319A. The Fe and Mg metallicity distributions are both asymmetric, with median values of +0.16 and +0.21 respectively. The iron distribution is clearly bimodal, as revealed both by a deconvolution (from observational errors) and a Gaussian decomposition. The decomposition of the observed Fe and Mg metallicity distributions into Gaussian components yields two populations of equal sizes (50% each): a metal-poor component centred around [Fe/H]=-0.30 and [Mg/H]=-0.06 with a large dispersion and a narrow metal-rich component centred around [Fe/H]=+0.32 and [Mg/H]=+0.35. The metal poor component shows high [Mg/Fe] ratios (around 0.3) whereas stars in the metal rich component are found to have near solar ratios. Babusiaux et al. (2010) also find kinematical differences between the two components: the metal poor component shows kinematics compatible with an old spheroid whereas the metal rich component is consistent with a population supporting a bar. In view of their chemical and kinematical properties, we suggest different formation scenarios for the two populations: a rapid formation timescale as an old spheroid for the metal poor component (old bulge) and for the metal rich component, a formation over a longer time scale driven by the evolution of the bar (pseudo-bulge)., Comment: Accepted for publication in Astronomy & Astrophysics
Published: 2011

93. Galactic bulge giants: probing stellar and galactic evolution I. Catalogue of Spitzer IRAC and MIPS sources

Author: Mathias Schultheis, Martin Groenewegen, S. Uttenthaler, Matthias Stute, Raghvendra Sahai, Stephan D. Price, Kathleen E. Kraemer, Joris Blommaert, Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Université d'Athènes (UOA), Dipartimento di Fisica Generale [Torino], Università degli studi di Torino (UNITO), 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), Air Force Research Laboratory (AFRL), United States Air Force (USAF), Observatoire Royal de Belgique, NASA-California Institute of Technology (CALTECH), Université de Franche-Comté (UFC), and 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)
Subjects: FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: AGB and post-AGB, Galaxy: bulge, Spitzer Space Telescope, Bulge, Astrophysics::Solar and Stellar Astrophysics, Stellar evolution, infrared: stars, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Physics, stars: late-type, Astronomy and Astrophysics, Paper based, Astrophysics - Astrophysics of Galaxies, Large sample, Red-giant branch, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: stellar content, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], stars: mass-loss, Data reduction
Abstract: Aims: We aim at measuring mass-loss rates and the luminosities of a statistically large sample of Galactic bulge stars at several galactocentric radii. The sensitivity of previous infrared surveys of the bulge has been rather limited, thus fundamental questions for late stellar evolution, such as the stage at which substantial mass-loss begins on the red giant branch and its dependence on fundamental stellar properties, remain unanswered. We aim at providing evidence and answers to these questions. Methods: To this end, we observed seven 15 times 15 arcmin^2 fields in the nuclear bulge and its vicinity with unprecedented sensitivity using the IRAC and MIPS imaging instruments on-board the Spitzer Space Telescope. In each of the fields, tens of thousands of point sources were detected. Results: In the first paper based on this data set, we present the observations, data reduction, the final catalogue of sources, and a detailed comparison to previous mid-IR surveys of the Galactic bulge, as well as to theoretical isochrones. We find in general good agreement with other surveys and the isochrones, supporting the high quality of our catalogue., Comment: 21 pages, accepted for publication in A&A. A version with high-resolution figures, as well as the data catalogues (including cross-id with GLIMPSE and GALCEN) and image mosaics are available at the anonymous ftp://ftp.ster.kuleuven.be/dist/stefan/Spitzer/
Published: 2010

94. Insights on the Milky Way bulge formation from the correlations between kinematics and metallicity

Author: Mathias Schultheis, A. Lecureur, F. Royer, Beatriz Barbuy, Sergio Ortolani, A. E. Gomez, R. Fux, Dante Minniti, C. Babusiaux, Vanessa Hill, Manuela Zoccali, Frédéric Arenou, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 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, 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), Pontificia Universidad Católica de Chile (UC), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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), Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo] (IAG), Universidade de São Paulo (USP), Specola Vaticana/Vatican Observatory, Universita degli Studi di Padova, Galilée (Galilée), Institut national des sciences de l'Univers (INSU - CNRS)-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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Metallicity, Milky Way, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Galaxy: bulge, Bulge, 0103 physical sciences, Galaxy formation and evolution, education, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, [PHYS]Physics [physics], Physics, education.field_of_study, 010308 nuclear & particles physics, Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Galaxy, Radial velocity, [SDU]Sciences of the Universe [physics], Galaxy: formation, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Galaxy: kinematics and dynamics
Abstract: Two main scenarios for the formation of the Galactic bulge are invoked, the first one through gravitational collapse or hierarchical merging of subclumps, the second through secular evolution of the Galactic disc. We aim to constrain the formation of the Galactic bulge through studies of the correlation between kinematics and metallicities in Baade's Window (l=1, b=-4) and two other fields along the bulge minor axis (l=0, b=-6 and b=-12). We combine the radial velocity and the [Fe/H] measurements obtained with FLAMES/GIRAFFE at the VLT with a spectral resolution of R=20000, plus for the Baade's Window field the OGLE-II proper motions, and compare these with published N-body simulations of the Galactic bulge. We confirm the presence of two distinct populations in Baade's Window found in Hill et al. 2010: the metal-rich population presents bar-like kinematics while the metal-poor population shows kinematics corresponding to an old spheroid or a thick disc one. In this context the metallicity gradient along the bulge minor axis observed by Zoccali et al. (2008), visible also in the kinematics, can be related to a varying mix of these two populations as one moves away from the Galactic plane, alleviating the apparent contradiction between the kinematic evidence of a bar and the existence of a metallicity gradient. We show evidences that the two main scenarios for the bulge formation co-exist within the Milky Way bulge., 10 pages, 8 figures, Accepted for publication in Astronomy & Astrophysics
Published: 2010

95. First Spectroscopic Identification of Massive Young Stellar Objects in the Galactic Center

Author: Susan R. Stolovy, Thomas P. Robitaille, Howard A. Smith, Angela S. Cotera, Deokkeun An, Mathias Schultheis, Kris Sellgren, Solange V. Ramirez, Adwin Boogert, Richard G. Arendt, Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), NASA ExoPlanet Science Institute (NExScI), Ohio State University [Columbus] (OSU), NASA Goddard Space Flight Center (GSFC), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Search for Extraterrestrial Intelligence Institute (SETI), Harvard-Smithsonian Center for Astrophysics (CfA), and Smithsonian Institution-Harvard University [Cambridge]
Subjects: 010504 meteorology & atmospheric sciences, Infrared, Young stellar object, Milky Way, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Spitzer Space Telescope, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Absorption (logic), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Galactic Center, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We report the detection of several molecular gas-phase and ice absorption features in three photometrically-selected young stellar object (YSO) candidates in the central 280 pc of the Milky Way. Our spectra, obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, reveal gas-phase absorption from CO2 (15.0um), C2H2 (13.7um) and HCN (14.0um). We attribute this absorption to warm, dense gas in massive YSOs. We also detect strong and broad 15um CO2 ice absorption features, with a remarkable double-peaked structure. The prominent long-wavelength peak is due to CH3OH-rich ice grains, and is similar to those found in other known massive YSOs. Our IRS observations demonstrate the youth of these objects, and provide the first spectroscopic identification of massive YSOs in the Galactic Center., Accepted for publication in ApJ Letters
Published: 2009

96. Technetium and lithium in Galactic bulge AGB stars

Author: M. T. Lederer, Hans Ulrich Käufl, Josef Hron, Thomas Lebzelter, Stefan Uttenthaler, Maurizio Busso, Sara Palmerini, Mathias Schultheis, Bernhard Aringer, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Universität Wien, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), and 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)
Subjects: Physics, 010308 nuclear & particles physics, stars: late-type, chemistry.chemical_element, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: AGB and post-AGB, Astrophysics, 01 natural sciences, Stars, chemistry, Space and Planetary Science, Observatory, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Lithium, Astrophysics::Earth and Planetary Astrophysics, stars: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Schwarzschild radius, Astrophysics::Galaxy Astrophysics
Abstract: International audience; Context.Technetium (Tc) is an unstable element synthesised via the s-process in deep layers of asymptotic giant branch (AGB) stars, making it a reliable indicator of both recent s-process activity and third dredge-up.Aims.We searched for Tc in a sample of bright oxygen-rich asymptotic giant branch (AGB) stars located in the outer galactic bulge. We test theoretical predictions of the luminosity limit for the onset of third dredge-up.Methods.Using high-resolution optical spectra obtained with the UVES spectrograph at ESO's VLT, we searched for resonance lines of neutral Tc in the blue spectral region of our sample stars. These measurements allow us to improve the procedure of classification of stars with respect to their Tc content by using flux ratios. Synthetic spectra based on MARCS atmospheric models are presented and compared to the observed spectra around three lines of Tc. Bolometric magnitudes are calculated based on the near-infrared photometry of the objects.Results.Among the sample of 27 long-period bulge variables, four were found to definitely contain Tc in their atmospheres. The luminosity of the Tc-rich stars agrees with predictions from AGB evolutionary models on the minimum luminosity at the time when third dredge-up sets in. However, AGB evolutionary models and a bulge consisting of a single old population cannot be brought into agreement. This probably means that a younger population is present in the bulge, as suggested by various authors, that contains the Tc-rich stars identified here.
Published: 2008

97. Stellar Populations in the Galactic Bulge

Author: Annie C. Robin, Mathias Schultheis, Alain Omont, B. Aringer, S. Ganesh, 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), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), Physical Research Laboratory [Ahmedabad] (PRL), Indian Space Research Organisation (ISRO), 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), Institut für Astronomie, Universität Wien (IFA), Universität Wien, K. Wada & F. Combes, eds., and Keiichi Wada, Françoise Combes
Subjects: Atomic Line, Synthetic Spectrum, Physics, Atomic line, Stellar population, 010308 nuclear & particles physics, Synthetic spectrum, Stellar collision, Astronomy, Astrophysics, 01 natural sciences, Equivalent Width, Photometric Data, Bulge, Stellar mass loss, 0103 physical sciences, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Stellar Population, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Equivalent width, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2006

98. Near-IR spectroscopy of OH/IR stars in the Galactic Centre

Author: A. Lancon, Mathias Schultheis, E. Vanhollebeke, B. Aringer, and Joris Blommaert
Subjects: Physics, education.field_of_study, Metallicity, Population, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Spectral line, Stars, Space and Planetary Science, Variable star, Spectroscopy, education, Line (formation)
Abstract: Context. Galactic Centre (GC) OH/IR stars can be, based on the expansion velocities of their circumstellar shells, divided into two groups which are kinematically different and therefore are believed to have evolved from different stellar populations. Aims. To study the metallicity distribution of the OH/IR stars population in the GC on basis of a theoretical relation between EW(Na), EW(Ca) and EW(CO) and the metallicity. Methods. For 70 OH/IR stars in the GC, we obtained near-IR spectra. The equivalent line widths of NaI, CaI, 12CO(2,0) and the curvature of the spectrum around 1.6 micron due to water absorption are determined. Results. The near-IR spectrum of OH/IR stars is influenced by several physical processes. OH/IR stars are variable stars suffering high mass-loss rates. The dust that is formed around the stars strongly influences the near-IR spectra and reduces the equivalent line widths of NaI, CaI. A similar effect is caused by the water content in the outer atmosphere of the OH/IR star. Because of these effects, it is not possible with our low resolution near-infrared spectroscopy to determine the metallicities of these stars., 20 pages, 21 figures, accepted for publication in A&A on 18/04/2006
Published: 2006

99. Stellar Populations in the Galactic Bulge

Author: Mathias Schultheis, Bernhard Aringer, and Ariane Lançon
Published: 2006

100. Optical spectroscopy of high proper motion stars: new M dwarfs within 10 pc and the closest pair of subdwarfs

Author: Céline Reylé, Mike Irwin, Mathias Schultheis, R.-D. Scholz, and Annie C. Robin
Subjects: Physics, Proper motion, Astrophysics (astro-ph), White dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Closest pair of points problem, Star (graph theory), Spectroscopic parallax, Stellar classification, Spectral line, Stars, Space and Planetary Science
Abstract: We present spectra of 59 nearby stars candidates, M dwarfs and white dwarfs, previously identified using high proper motion catalogues and the DENIS database. We review the existing spectral classification schemes and spectroscopic parallax calibrations in the near-infrared $J$-band and derive spectral types and distances of the nearby candidates. 42 stars have spectroscopic distances smaller than 25 pc, three of them being white dwarfs. Two targets lie within 10 pc, one M8 star at 10.0 pc (APMPM J0103-3738), and one M4 star at 8.3 pc (LP 225-57). One star, LHS 73, is found to be among the few subdwarfs lying within 20 pc. Furthermore, together with LHS 72, it probably belongs to the closest pair of subdwarfs we know., Comment: 10 pages, 7 figures, accepted for publication in MNRAS
Published: 2006
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