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

Abstract

We have reanalyzed the OGLE $V$ and $I$ photometry of $\sim 500,000$ 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 Paczyński 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 $V>18$ have their $(V-I)$ color indices too red by $\sim 0.1mag$. We find tentative evidence from the OGLE and HST photometry that the the bulge main sequence turn--off point is brighter by $\sim 0.5mag$ 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.

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

References in corpus (5)

• Modelling the Galactic Bar Using Red Clump Giants
• Color-Magnitude Diagram Distribution of the Bulge Red Clump Stars - Evidence for the Galactic Bar
• Extinction Map of Baade's Window
• The Distribution of Galactic Disk Stars in Baade's Window
• Variations of the Selective Extinction Across the Galactic Bulge - Implications for the Galactic Bar

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• The Microlensing Event Rate and Optical Depth Toward the Galactic Bulge from MOA-II
• Possible Solution of the long-standing discrepancy in the Microlensing Optical Depth Toward the Galactic Bulge by correcting the stellar number count
• Evidence for a deficit of young and old stars in the Milky Way inner in-plane disc
• The Large-Scale Extinction Map of the Galactic Bulge from the MACHO Project Photometry
• Eclipsing Binaries in the OGLE Variable Star Catalog.III. Long-Period Contact Systems
• Mapping the Interstellar Reddening and Extinction towards Baade's Window Using Minimum Light Colors of ab-type RR Lyrae Stars. Revelations from the De-reddened Color-Magnitude Diagrams
• A Near-Infrared Photometric Survey of Metal-Poor Inner Spheroid Globular Clusters and Nearby Bulge Fields
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• Eclipsing Binaries in the OGLE Variable Star Catalog. IV. The Pre-Contact, Equal-Mass Systems
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