skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy

Abstract

The Apache Point Observatory Galactic Evolution Experiment provides the opportunity of measuring 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 thechemical-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 it is the first time that 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] ≳ −0.8 are deficient in all elemental abundance ratios (expressed as [X/Fe]) relative to the Milky Way, suggesting that the 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 initial mass function, one lacking the most massive stars that would normally pollute the interstellar medium with the hydrostaticmore » elements. We use a simple chemical-evolution model, flexCE, to further support our claim and conclude that recent stellar generations of Fornax and the Large Magellanic Cloud could also have formed according to a top-light initial mass function.« less

Authors:
;  [1];  [2]; ;  [3];  [4]; ;  [5];  [6]; ;  [7];  [8]; ; ;  [9]; ; ;  [10];  [11];  [12] more »; « less
  1. New Mexico State University, Las Cruces, NM 88003 (United States)
  2. University of Texas at Austin, McDonald Observatory, Fort Davis, TX 79734 (United States)
  3. National Optical Astronomy Observatories, Tucson, AZ 85719 (United States)
  4. The Observatories of the Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  5. Departamento de Astronomía, Casilla 160-C, Universidad de Concepción, Concepción (Chile)
  6. Department of Physics and JINA Center for the Evolution of the Elements, University of Notre Dame, Notre Dame, IN 46556 (United States)
  7. Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States)
  8. Department of Physics, Universidad Andres Bello, 700 Fernandez Concha (Chile)
  9. Instituto de Astronomía, Universidad Nacional Autnoma de México, Apdo. Postal 70264, Ciudad de México, 04510 (Mexico)
  10. Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)
  11. Departamento de Física, Facultad de Ciencias, Universidad de La Serena, Cisternas 1200, La Serena (Chile)
  12. Texas Christian University, Fort Worth, TX 76129 (United States)
Publication Date:
OSTI Identifier:
22663205
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 845; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ELEMENT ABUNDANCE; GALACTIC EVOLUTION; HYDROSTATICS; ISOCHRONOUS CYCLOTRONS; MAGELLANIC CLOUDS; MASS; MILKY WAY; RED GIANT STARS; RESOLUTION; VISIBLE RADIATION

Citation Formats

Hasselquist, Sten, Holtzman, Jon, Shetrone, Matthew, Smith, Verne, Nidever, David L., McWilliam, Andrew, Fernández-Trincado, J. G., Tang, Baitian, Beers, Timothy C., Majewski, Steven R., Anguiano, Borja, Tissera, Patricia B., Alvar, Emma Fernández, Carigi, Leticia, Delgado Inglada, Gloria, Allende Prieto, Carlos, Battaglia, Giuseppina, García-Hernández, D. A., Almeida, Andres, Frinchaboy, Peter, E-mail: sten@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: shetrone@astro.as.utexas.edu, E-mail: vsmith@email.noao.edu, and and others. APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7DDC.
Hasselquist, Sten, Holtzman, Jon, Shetrone, Matthew, Smith, Verne, Nidever, David L., McWilliam, Andrew, Fernández-Trincado, J. G., Tang, Baitian, Beers, Timothy C., Majewski, Steven R., Anguiano, Borja, Tissera, Patricia B., Alvar, Emma Fernández, Carigi, Leticia, Delgado Inglada, Gloria, Allende Prieto, Carlos, Battaglia, Giuseppina, García-Hernández, D. A., Almeida, Andres, Frinchaboy, Peter, E-mail: sten@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: shetrone@astro.as.utexas.edu, E-mail: vsmith@email.noao.edu, & and others. APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy. United States. doi:10.3847/1538-4357/AA7DDC.
Hasselquist, Sten, Holtzman, Jon, Shetrone, Matthew, Smith, Verne, Nidever, David L., McWilliam, Andrew, Fernández-Trincado, J. G., Tang, Baitian, Beers, Timothy C., Majewski, Steven R., Anguiano, Borja, Tissera, Patricia B., Alvar, Emma Fernández, Carigi, Leticia, Delgado Inglada, Gloria, Allende Prieto, Carlos, Battaglia, Giuseppina, García-Hernández, D. A., Almeida, Andres, Frinchaboy, Peter, E-mail: sten@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: shetrone@astro.as.utexas.edu, E-mail: vsmith@email.noao.edu, and and others. Sun . "APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy". United States. doi:10.3847/1538-4357/AA7DDC.
@article{osti_22663205,
title = {APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy},
author = {Hasselquist, Sten and Holtzman, Jon and Shetrone, Matthew and Smith, Verne and Nidever, David L. and McWilliam, Andrew and Fernández-Trincado, J. G. and Tang, Baitian and Beers, Timothy C. and Majewski, Steven R. and Anguiano, Borja and Tissera, Patricia B. and Alvar, Emma Fernández and Carigi, Leticia and Delgado Inglada, Gloria and Allende Prieto, Carlos and Battaglia, Giuseppina and García-Hernández, D. A. and Almeida, Andres and Frinchaboy, Peter, E-mail: sten@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: shetrone@astro.as.utexas.edu, E-mail: vsmith@email.noao.edu and and others},
abstractNote = {The Apache Point Observatory Galactic Evolution Experiment provides the opportunity of measuring 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 thechemical-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 it is the first time that 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] ≳ −0.8 are deficient in all elemental abundance ratios (expressed as [X/Fe]) relative to the Milky Way, suggesting that the 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 initial mass function, one lacking the most massive stars that would normally pollute the interstellar medium with the hydrostatic elements. We use a simple chemical-evolution model, flexCE, to further support our claim and conclude that recent stellar generations of Fornax and the Large Magellanic Cloud could also have formed according to a top-light initial mass function.},
doi = {10.3847/1538-4357/AA7DDC},
journal = {Astrophysical Journal},
number = 2,
volume = 845,
place = {United States},
year = {Sun Aug 20 00:00:00 EDT 2017},
month = {Sun Aug 20 00:00:00 EDT 2017}
}