publication . Preprint . Article . Other literature type . 2016

COMPLETE ELEMENT ABUNDANCES OF NINE STARS IN THE r-PROCESS GALAXY RETICULUM II*

Ji, Alexander P.; Frebel, Anna; Simon, Joshua D.; Chiti, Anirudh;
Open Access English
  • Published: 14 Oct 2016
Abstract
We present chemical abundances derived from high-resolution Magellan/MIKE spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II. These stars span the full metallicity range of Ret II (-3.5 < [Fe/H] < -2). Seven of the nine stars have extremely high levels of r-process material ([Eu/Fe]~1.7), in contrast to the extremely low neutron-capture element abundances found in every other ultra-faint dwarf galaxy studied to date. The other two stars are the most metal-poor stars in the system ([Fe/H] < -3), and they have neutron-capture element abundance limits similar to those in other ultra-faint dwarf galaxies. We confirm th...
Subjects
arXiv: Astrophysics::Galaxy AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary Astrophysics
free text keywords: Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astronomy and Astrophysics, Metallicity, Dwarf galaxy, Abundance of the chemical elements, Luminosity function (astronomy), Physics, Red giant, Astrophysics, Type-cD galaxy, Galaxy, Astronomy, K-type main-sequence star
Funded by
NSF| CAREER: The origin of the metal-poor halo of the Milky Way
Project
  • Funder: National Science Foundation (NSF)
  • Project Code: 1255160
  • Funding stream: Directorate for Mathematical & Physical Sciences | Division of Astronomical Sciences
,
NSF| JINA Center for the Evolution of the Elements
Project
  • Funder: National Science Foundation (NSF)
  • Project Code: 1430152
  • Funding stream: Directorate for Mathematical & Physical Sciences | Division of Physics
160 references, page 1 of 11

Aoki, W., Beers, T. C., Christlieb, N., et al. 2007a, ApJ, 655, 492

Aoki, W., Beers, T. C., Honda, S., & Carollo, D. 2010, ApJL, 723, L201

Aoki, W., Honda, S., Sadakane, K., & Arimoto, N. 2007b, PASJ, 59, L15

Arcones, A., Janka, H.-T., & Scheck, L. 2007, A&A, 467, 1227

Arcones, A., & Montes, F. 2011, ApJ, 731, 5

Argast, D., Samland, M., Thielemann, F.-K., & Qian, Y.-Z. 2004, A&A, 416, 997

Asplund, M., Grevesse, N., Sauval, A. J., & Scott, P. 2009, ARA&A, 47, 481

Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33

Barklem, P. S., Christlieb, N., Beers, T. C., et al. 2005, A&A, 439, 129

Bechtol, K., Drlica-Wagner, A., Balbinot, E., et al. 2015, ApJ, 807, 50

Berger, E., Fong, W., & Chornock, R. 2013, ApJL, 774, L23

Bernstein, R., Shectman, S. A., Gunnels, S. M., Mochnacki, S., & Athey, A. E. 2003, Proc. SPIE, 4841, 1694

Bland-Hawthorn, J., Sutherland, R., & Webster, D. 2015, ApJ, 807, 154

Bohlin, R. C., Jenkins, E. B., Spitzer, Jr., L., et al. 1983, ApJS, 51, 277

Brown, T. M., Tumlinson, J., Geha, M., et al. 2014, ApJ, 796, 91

160 references, page 1 of 11
Related research
Abstract
We present chemical abundances derived from high-resolution Magellan/MIKE spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II. These stars span the full metallicity range of Ret II (-3.5 < [Fe/H] < -2). Seven of the nine stars have extremely high levels of r-process material ([Eu/Fe]~1.7), in contrast to the extremely low neutron-capture element abundances found in every other ultra-faint dwarf galaxy studied to date. The other two stars are the most metal-poor stars in the system ([Fe/H] < -3), and they have neutron-capture element abundance limits similar to those in other ultra-faint dwarf galaxies. We confirm th...
Subjects
arXiv: Astrophysics::Galaxy AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary Astrophysics
free text keywords: Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astronomy and Astrophysics, Metallicity, Dwarf galaxy, Abundance of the chemical elements, Luminosity function (astronomy), Physics, Red giant, Astrophysics, Type-cD galaxy, Galaxy, Astronomy, K-type main-sequence star
Funded by
NSF| CAREER: The origin of the metal-poor halo of the Milky Way
Project
  • Funder: National Science Foundation (NSF)
  • Project Code: 1255160
  • Funding stream: Directorate for Mathematical & Physical Sciences | Division of Astronomical Sciences
,
NSF| JINA Center for the Evolution of the Elements
Project
  • Funder: National Science Foundation (NSF)
  • Project Code: 1430152
  • Funding stream: Directorate for Mathematical & Physical Sciences | Division of Physics
160 references, page 1 of 11

Aoki, W., Beers, T. C., Christlieb, N., et al. 2007a, ApJ, 655, 492

Aoki, W., Beers, T. C., Honda, S., & Carollo, D. 2010, ApJL, 723, L201

Aoki, W., Honda, S., Sadakane, K., & Arimoto, N. 2007b, PASJ, 59, L15

Arcones, A., Janka, H.-T., & Scheck, L. 2007, A&A, 467, 1227

Arcones, A., & Montes, F. 2011, ApJ, 731, 5

Argast, D., Samland, M., Thielemann, F.-K., & Qian, Y.-Z. 2004, A&A, 416, 997

Asplund, M., Grevesse, N., Sauval, A. J., & Scott, P. 2009, ARA&A, 47, 481

Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33

Barklem, P. S., Christlieb, N., Beers, T. C., et al. 2005, A&A, 439, 129

Bechtol, K., Drlica-Wagner, A., Balbinot, E., et al. 2015, ApJ, 807, 50

Berger, E., Fong, W., & Chornock, R. 2013, ApJL, 774, L23

Bernstein, R., Shectman, S. A., Gunnels, S. M., Mochnacki, S., & Athey, A. E. 2003, Proc. SPIE, 4841, 1694

Bland-Hawthorn, J., Sutherland, R., & Webster, D. 2015, ApJ, 807, 154

Bohlin, R. C., Jenkins, E. B., Spitzer, Jr., L., et al. 1983, ApJS, 51, 277

Brown, T. M., Tumlinson, J., Geha, M., et al. 2014, ApJ, 796, 91

160 references, page 1 of 11
Related research
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publication . Preprint . Article . Other literature type . 2016

COMPLETE ELEMENT ABUNDANCES OF NINE STARS IN THE r-PROCESS GALAXY RETICULUM II*

Ji, Alexander P.; Frebel, Anna; Simon, Joshua D.; Chiti, Anirudh;