High-Resolution X-Ray Observations of M33

Why is it important?

With current X-ray instrumentation, only in the Milky Way, the Magellanic Clouds, M31, and M33 can one study fundamental galactic X-ray sources in significant numbers: X-ray binaries, supernova remnants, and superbubbles. Superbubbles and supernova remnants are difficult to find and study in large numbers in our own Galaxy because gas in the Galactic disk has column densities sufficient to absorb much of the soft X-ray emission. The distances are difficult to determine to Galactic X-ray sources, making their luminosities very uncertain. The Magellanic Clouds are irregular galaxies and are very different from the Milky Way, with many more luminous supernova remnants, a different population of X-ray binaries, and hotter interstellar media. M31 is edge on, making complete surveys difficult, and also has little active star formation. M33, on the other hand, is a normal spiral galaxy that is actively forming stars, relatively face-on, and has a well-determined distance.

What did I do?

I used ROSAT , Einstein Observatory , and ASCA observations of M33 to search for and study X-ray binaries, supernova remnants, and superbubbles. I found two potential superbubbles of hot gas within holes in the neutral hydrogen layer of the galaxy, eight X-ray sources that are probably associated with supernova remnants, and numerous bright X-ray point sources that are probably X-ray binaries.

Journal Articles