English

The Color--Magnitude Diagram in Baade's Window Revisited

Astrophysics 2009-10-28 v1

Abstract

We have reanalyzed the OGLE VV and II photometry of 500,000\sim 500,000 stars in Baade's Window, and we confirm the extinction map published by Stanek (1996). However, we find that the interpretation of the OGLE color--magnitude diagram for the disk stars proposed by Paczy\'nski et al. (1994) was incorrect: the dominant disk population in Baade's Window is old, and we find no evidence for a large hole in the inner Galactic disk. We find evidence for a small systematic error in the OGLE photometry for stars below the ``red clump'': the faint stars with V>18V>18 have their (VI)(V-I) color indices too red by 0.1  mag\sim 0.1\;mag. We find tentative evidence from the OGLE and HST photometry that the the bulge main sequence turn--off point is brighter by 0.5  mag\sim 0.5 \;mag than it is in either 47~Tuc or NGC~6791, indicating that the dominant population of the Galactic bulge is considerably younger than those clusters.

Keywords

Cite

@article{arxiv.astro-ph/9608169,
  title  = {The Color--Magnitude Diagram in Baade's Window Revisited},
  author = {M. Kiraga and B. Paczynski and K. Z. Stanek},
  journal= {arXiv preprint arXiv:astro-ph/9608169},
  year   = {2009}
}

Comments

submitted to the Astrophysical Journal, 17 pages, 9 figures, 4 figures included; all figures are available using ftp://www.astro.princeton.edu/stanek/Kiraga