The Chandra ACIS Survey of M33 (ChASeM33) is a very deep X-ray survey of the
nearest face-on spiral galaxy, M33, using the superb spatial resolution of the Chandra X-ray Observatory.
In order to understand motivation and scope of the survey, it is useful to know that it is in spiral galaxies that much of the drama
of the present universe plays out: stellar birth and death, the recycling of matter from interstellar gas to stars and back again. X-ray observations - whether of vast interstellar structures or of tiny collapsed stars - provide crucial diagnostics in our effort to record and understand these processes which are so important for the evolution of galaxies. Since we live within the Galaxy, our view is badly compromised by obscuring clouds of dust and gas, a lack of reliable distance indicators, and a confusing welter of overlapping features along each line of sight. To observe and ultimately understand the full drama, we must look beyond the Galaxy.
The best target to achieve such a global perspective is M33.
M33 is a late-type Sc spiral, the third largest spiral in the Local Group after M31 and the Milky Way (MW). At a distance of 2.6 million light years, 1" subtends 13 light years in M33. The galaxy's intermediate inclination angle of 56 degrees and low internal extinction make it the ideal target for exploring the global structure of the Interstellar Medium (ISM) and the stellar populations that shape it.
Left: M33 as seen in the optical from the ground. The bright bluish region in the upper left is NGC604, a giant HII-region in M33. Right: A three color composite X-ray image taken by the Chandra X-ray Observatory (red: 0.3-1.1keV, green: 1.1-2.6keV, blue: 2.6-8.0keV). The reddish object seen in the upper left is again NGC604.
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