AAS 204th Meeting, June 2004
Session 49 X-ray Binary and ULX Populations in Nearby Galaxies
Topical Session, Wednesday, June 2, 2004, 8:30-10:00am, 10:45am-12:30pm, 2:30-4:00pm, 4:15-6:00pm, 601

[49.14] The X-ray binary population in the M33

H.-J. Grimm, J.C. McDowell, D.-W. Kim, A. Zezas, G. Fabbiano (CfA)

We present an investigation of the X-ray binary population of the Local Group galaxy M33. M33 is a missing link'' in galaxy populations observed with Chandra. Morphologically it lies between early-type spiral galaxies (M31, Milky Way) and dwarf galaxies (SMC, IC 1613). M33's proximity (840 kpc) and low line-of-sight column density (NH ~6 \times 1020 cm2) provide unique advantages for the study of the X-ray population of a spiral galaxy: It provides the same amount of detail as achievable in M31 and allows the study of a luminosity range unaccessible in more distant galaxies and more difficult to observe in either the MW, M31 or LMC/SMC. Moreover, the higher star formation rate results in a different population of X-ray sources compared to the MW or M31.

Here we present the luminosity function of X-ray point sources, ranging from a few 1035 - 1038 erg/s. We use optical identifications and other properties of the X-ray sources to study the population in greater detail. The results are compared with other galaxies, mainly the Milky Way and M31.

We acknowledge support by NASA grant GO2-3135X.

Bulletin of the American Astronomical Society, 36 #2
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