Red clump giant stars as tracers of Galactic structure

López-Corredoira, M.; Cabrera-Lavers, A.; Hammersley, P. L.; Garzón, F.; Mahoney, T. J.; González-Fernández, C.
Bibliographical reference

Highlights of Astronomy, Volume 15, p. 811-811

Advertised on:
11
2010
Number of authors
6
IAC number of authors
6
Citations
2
Refereed citations
2
Description
By isolating the red clump giant population in the color-magnitude diagrams and inverting their star counts, we can obtain directly the density distribution of the old stellar population along the line of sight. We have applied this method to several near infrared surveys and obtained information on the disc, bulge and long bar. The disc is well fitted by an exponential distribution in both the galactocentric distance and height, flared and warped in the outer parts, and with a deficit of stars in the inner in-plane regions. The long bar occupies these in-plane regions within R < 3.9 kpc, with approximate dimensions of 7.8 kpc × 1.2 kpc × 0.2 kpc and a position angle of 40-45 deg. The bulge is a triaxial structure, possibly boxy, thicker and shorter than the long bar and with position angle of 10-30 deg.