Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-25T03:46:21.272Z Has data issue: false hasContentIssue false
  • English
  • Français

Two New Ultra-Faint Star Clusters in the Milky Way Halo

Published online by Cambridge University Press:  09 May 2016

Dongwon Kim
Dongwon Kim*
Affiliation:
Research School of Astronomy and Astrophysics, The Australian National University, Mt Stromlo Observatory, via Cotter Rd, Weston, ACT 2611, Australia email: dongwon.kim@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.

Kim 1 & 2 are two new star clusters discovered in the Stromlo Missing Satellite Survey. Kim 1, located at a heliocentric distance of 19.8 ± 0.9 kpc, features an extremely low total luminosity (MV = 0.3 ± 0.5 mag) and low star concentration. Together with the large ellipticity (ε = 0.42 ± 0.10) and irregular isophotes, these properties suggest that Kim 1 is an intermediate mass star cluster being stripped by the Galactic tidal field. Kim 2 is a rare ultra-faint outer halo globular cluster located at a heliocentric distance of 104.7 ± 4.1 kpc. The cluster exhibits evidence of significant mass loss such as extra-tidal stars and mass-segregation. Kim 2 is likely to follow an orbit confined to the peripheral region of the Galactic halo, and/or to have formed in a dwarf galaxy that was later accreted into the Galactic halo.

Keywords

Galaxyhaloglobular clustersdwarf galaxies
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 11 , Issue S317: The General Assembly of Galaxy Halos: Structure, Origin and Evolution , August 2015 , pp. 314 - 315
Copyright
Copyright © International Astronomical Union 2016 

References

Ahn, C. P., Alexandroff, R., Allende Prieto, C., et al. 2014, ApJS, 211, 17CrossRefGoogle Scholar
Fadely, R., Willman, B., Geha, M., et al. 2011, AJ, 142, 88Google Scholar
Kim, D. & Jerjen, H. 2015a, ApJ, 799, 73Google Scholar
Kim, D., Jerjen, H., Milone, A. P., Mackey, D., & Da Costa, G. S. 2015a, ApJ, 803, 63Google Scholar
Kim, D., Jerjen, H., Mackey, D., Da Costa, G. S., & Milone, A. P. 2015b, ApJL, 804, L44CrossRefGoogle Scholar
Kim, D. & Jerjen, H. 2015b, ApJL, 808, L39Google Scholar
Koposov, S., de Jong, J. T. A., Belokurov, V., et al. 2007, ApJ, 669, 337Google Scholar
Muñoz, R. R., Geha, M., Côté, P., et al. 2012, ApJL, 753, L15Google Scholar
Pawlowski, M.S., McGaugh, S.S., & Jerjen, H. 2015 MNRAS, 453, 1047Google Scholar
Sollima, A., Martínez-Delgado, D., Valls-Gabaud, D., & Peñarrubia, J. 2011, ApJ, 726, 47Google Scholar