Hostname: page-component-7c8c6479df-27gpq Total loading time: 0 Render date: 2024-03-28T15:38:59.842Z Has data issue: false hasContentIssue false

Relics of Primordial Star Formation: The Milky Way and Local Dwarfs

Published online by Cambridge University Press:  01 June 2008

Timothy C. Beers
Affiliation:
Department of Physics & Astronomy, CSCE: Center for the Study of Cosmic Evolution, and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824, USA email: beers@pa.msu.edu, lee@pa.msu.edu
Young Sun Lee
Affiliation:
Department of Physics & Astronomy, CSCE: Center for the Study of Cosmic Evolution, and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824, USA email: beers@pa.msu.edu, lee@pa.msu.edu
Daniela Carollo
Affiliation:
Research School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, Cotter Road, Weston, ACT 2611, Australia, and INAF-Osservatorio Astronomico di Torino, 10025 Pino Torinese, Italy, email: carollo@mso.anu.edu.au
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Massive spectroscopic surveys of stars in the thick disk and halo populations of the Galaxy hold the potential to provide strong constraints on the processes involved in (and the timing of) the assembly history of the primary structural components of the Galaxy. In this talk, we explore what has been learned from one of the first such dedicated surveys, SDSS/SEGUE. Over the course of the past three years, SEGUE has obtained spectra for over 200,000 stars, while another hundred thousand stars been added from the calibration star observations of the (primarily extragalactic) SDSS, and other directed programs. A total of well over 10,000 stars with [Fe/H] < −2.0 have been discovered, including several hundred with [Fe/H] < −3.0. Their kinematics have revealed a inner/outer halo structure of the Galaxy.

New determinations of the alpha element ratios for tens of thousands of these stars are reported. Correlations of the alpha-element ratios with kinematics and orbital parameters can be used to test models of the likely formation of the thick-disk and halo components. These new data will (eventually) be considered in connection with possible associations with the present dwarf satellite galaxies of the Milky Way.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2008

References

Adelman-McCarthy, J. K, Agüeros, M. A., Allah, S. S, Allende Prieto, C., & Anderson, K. S. J., et al. 2008, ApJS, 175, 297Google Scholar
Allende Prieto, C., Beers, T. C., Wilhelm, R., Newberg, H. J., & Rockosi, C. M., et al. 2006, ApJ, 636, 804Google Scholar
Beers, T. C., Rossi, S., Norris, J. E., Ryan, S. G., & Shefler, T. 1999, AJ, 117, 981CrossRefGoogle Scholar
Bekki, K. & Chiba, M. 2001, ApJ, 558, 666CrossRefGoogle Scholar
Allende Prieto, C., Sivarani, T., Beers, T. C., Lee, Y. S., & Koesterke, L. et al. 2008, AJ, in press (arXiv:0710.5780)Google Scholar
Belokurov, V., Zucker, D. B., Evans, N. W., Gilmore, G., & Vidrih, S., et al. 2006, ApJ, 642, L137Google Scholar
Carollo, D., Beers, T. C., Lee, Y. S., Chiba, M., & Norris, J. E., et al. 2007, Nature, 450, 1020CrossRefGoogle Scholar
Cenarro, A. J., Cardiel, N, Gorgas, J., Peletier, R. F., Vazdekis, A., & Prada, F. 2001, MNRAS, 326, 959Google Scholar
Diemand, J., Kuhlen, M., & Madau, P. 2007 2007, ApJ, 667, 859CrossRefGoogle Scholar
Johnston, K. V., Bullock, J. S., Sharma, S., Font, A., Robertson, B. E., & Leitner, S. N. 2008, ApJ, in press (arXiv:0807.3911)Google Scholar
Lee, Y. S., Beers, T.C., Sivarani, T., Allende Prieto, C., & Koesterke, L., et al. 2008, AJ, in press (arXiv:0710.5645)Google Scholar
Lee, Y. S., Beers, T. C., Sivarani, T., Johnson, J. A., & An, D., et al. 2008, AJ, in press (arXiv:0710.5778)Google Scholar
Moultaka, J., Ilovaisky, S. A., Prugniel, P., & Soubiran, C. 2004, PASP, 116, 693CrossRefGoogle Scholar
Re Fiorentin, P., Bailer-Jones, C. A. L., Lee, Y. S., Beers, T. C., & Sivarani, T., et al. 2007, A&A, 467, 1373Google Scholar
Tumlinson, J. 2006, ApJ, 641, 1Google Scholar
Walsh, S. M., Willman, B., & Jerjen, H. 2008, AJ, submitted (arXiv:0807.3345)Google Scholar
Wilhelm, R., Beers, T. C., & Gray, R. O. 1999, AJ, 117, 2308CrossRefGoogle Scholar
Zucker, D. B., Belokurov, V., Evans, N. W., Wilkinson, M. I., & Irwin, M. J., et al. 2006, ApJ, 643, L103CrossRefGoogle Scholar