Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-25T08:19:35.977Z Has data issue: false hasContentIssue false

Halo K-Giant Stars from LAMOST: Kinematics and Galactic Mass Estimate

Published online by Cambridge University Press:  21 March 2017

Sarah A. Bird*
Affiliation:
Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai 200030, China email: sarahbird@shao.ac.cn
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.

We analyze line-of-sight velocities of over 3000 halo K-giant stars from the second data release of the spectral survey LAMOST (Zhao et al. 2012). We find a nearly constant velocity dispersion profile, with no large dips or peaks, in a Galactocentric radial range of 10–30 kpc, in accord with earlier analyses (Battaglia et al. 2005, 2006; Xue et al. 2008, 2014) (see Fig. 1). Previous studies of halo star radial velocity dispersions in a reference frame centered on the Galactic Center have detected dips within this radial range (Sommer-Larsen et al. 1994; Kafle et al. 2012, 2014). We use the stars to make estimates of the enclosed mass out to 40 kpc from the Galactic Center using the method of Evans et al. (2011). Tens of thousands of such stars are expected to become available to this analysis by the end of the five-year survey.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2017 

References

Battaglia, G., Helmi, A., Morrison, H., et al. 2005, MNRAS, 364, 433 CrossRefGoogle Scholar
Battaglia, G., Helmi, A., Morrison, H., et al. 2006, MNRAS, 370, 1055 Google Scholar
Bird, S. A., Liu, C., Shen, J., & Xue, X. X. 2016, in preparationGoogle Scholar
Evans, N. W., An, J., & Deason, A. J. 2011, ApJ, 730, L26 Google Scholar
Kafle, P. R., Sharma, S., Lewis, G. F., & Bland-Hawthorn, J. 2012, ApJ, 761, 98 CrossRefGoogle Scholar
Kafle, P. R., Sharma, S., Lewis, G. F., & Bland-Hawthorn, J. 2014, ApJ, 794, 59 Google Scholar
Sommer-Larsen, J., Flynn, C., & Christensen, P. R. 1994, MNRAS, 271, 94 Google Scholar
Xue, X. X., Rix, H. W., Zhao, G., et al. 2008, ApJ, 684, 1143 Google Scholar
Xue, X.-X., Ma, Z., Rix, H.-W., et al. 2014, ApJ, 784, 170 Google Scholar
Zhao, G., Zhao, Y.-H., Chu, Y.-Q., Jing, Y.-P., & Deng, L.-C. 2012, RAA, 12, 723 Google Scholar