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Stellar Populations of the Outer Milky-Way Halo

Published online by Cambridge University Press:  02 August 2018

Baslio Santiago
Affiliation:
Instituto de Física, UFRGS, Campus do Vale, Caixa Postal 15051
Elmer Luque
Affiliation:
Instituto de Física, UFRGS, Campus do Vale, Caixa Postal 15051
Adriano Pieres
Affiliation:
Instituto de Física, UFRGS, Campus do Vale, Caixa Postal 15051
Anna Bárbara Queiroz
Affiliation:
Instituto de Física, UFRGS, Campus do Vale, Caixa Postal 15051
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Abstract

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The stellar spheroidal components of the Milky-Way contain the oldest and most metal poor of its stars. Inevitably the processes governing the early stages of Galaxy evolution are imprinted upon them. According to the currently favoured hierarchical bottom-up scenario of galaxy formation, these components, specially the Galactic halo, are the repository of most of the mass built up from accretion events in those early stages. These events are still going on today, as attested by the long stellar streams associated to the Sagittarius dwarf galaxy and several other observed tidal substructure, whose geometry, extent, and kinematics are important constraints to reconstruct the MW gravitational potential and infer its total (visible + dark) mass. In addition, the remaining system of MW satellites is expected to be a fossil record of the much larger population of Galactic building blocks that once existed and got accreted. For all these reasons, it is crucial to unravel as much of this remaining population as possible, as well as the current stellar streams that orbit within the halo. The best bet to achieve this task is to carry out wide, deep, and multi-band photometric surveys that provide homogeneous stellar samples. In this contribution, we summarize the results of several years of work towards detecting and characterizing distant MW stellar systems, star clusters and dwarf spheroidals alike, with an emphasis on the analysis of data from the Dark Energy Survey (DES). We argue that most of the volume in distance, size and luminosity space, both in the Galaxy and in the Clouds, is still unprobed. We then discuss the perspectives of exploring this outer MW volume using the current surveys, as well as other current and future surveys, such as the Large Synoptic Survey Telescope (LSST).

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

Abell, G. O., 1955, PASP, 67, 258Google Scholar
Balbinot, E., Santiago, B. X., da Costa, L. N., Makler, M., & Maia, M. A. G., 2011, MNRAS, 416, 393Google Scholar
Bechtol, K., Drlica-Wagner, A., Balbinot, E., et al. 2015, ApJ, 807, 50Google Scholar
Bertin, E. & Arnouts, S., 1996, A&AS, 117, 393Google Scholar
Bland-Hawthorn, J. & Gerhard, O., 2016, ARA&A, 54, 529Google Scholar
Carollo, D., Beers, T. C., Lee, Y. S., et al. 2007, Nature Physics, 450, 1020Google Scholar
Chabrier, G., 2003, PASP, 115, 763Google Scholar
Drlica-Wagner, A., Bechtol, K., Rykoff, E. S., et al. 2015, ApJ, 813, 109Google Scholar
Girardi, L., Barbieri, M., Groenewegen, M. A. T., et al. 2012, TRILEGAL, a TRIdimensional modeL of thE GALaxy: Status and Future, ed. A. Miglio, J. Montalbán, & A. Noels, 165Google Scholar
Gómez, F. A., Besla, G., Carpintero, D. D., et al. 2015, ApJ, 802, 128Google Scholar
Harris, W. E. 2010, ArXiv e-printsGoogle Scholar
Ivezic, Z., Axelrod, T., Brandt, W. N., et al. 2008, Serbian Astronomical Journal, 176, 1Google Scholar
Jethwa, P., Erkal, D., & Belokurov, V., 2016, MNRAS, 461, 2212Google Scholar
Koposov, S., Belokurov, V., Evans, N. W., et al. 2008, ApJ, 686, 279Google Scholar
Koposov, S. E., Belokurov, V., Torrealba, G., & Evans, N. W., 2015, ApJ, 805, 130Google Scholar
Kroupa, P., 2001, MNRAS, 322, 231Google Scholar
Laevens, B. P. M., Martin, N. F., Ibata, R. A., et al. 2015, ApJ Letters, 802, L18Google Scholar
Luque, E., Pieres, A., Santiago, B., et al. 2017, MNRAS, 468, 97Google Scholar
Luque, E., Queiroz, A., Santiago, B., et al. 2016, MNRAS, 458, 603Google Scholar
McConnachie, A. W., 2012, AJ, 144, 4Google Scholar
Pawlowski, M. S., McGaugh, S. S., & Jerjen, H., 2015, MNRAS, 453, 1047Google Scholar
Rockosi, C. M., Odenkirchen, M., Grebel, E. K., et al. 2002, AJ, 124, 349Google Scholar
Skrutskie, M. F., Cutri, R. M., Stiening, R., et al. 2006, AJ, 131, 1163Google Scholar
The Dark Energy Survey Collaboration. 2005, ArXiv Astrophysics e-printsGoogle Scholar
York, D. G., Adelman, J., Anderson, J. E. Jr, Anderson, S. F., et al. 2000, AJ, 120, 1579Google Scholar