AAS 204th Meeting, June 2004
Session 45 The Galaxy and The Magellanic Clouds
Poster, Tuesday, June 1, 2004, 10:00am-7:00pm, Ballroom

[Previous] | [Session 45] | [Next]

[45.01] Massive Star Clusters in the ASCA Galactic Plane Survey

J.P. Simpson, A.S. Cotera (SETI Institute)

Sujizaki et al. (2002, ApJS, 134, 77) surveyed the Galactic Ridge for X-ray sources with the Advanced Satellite for Cosmology and Astrophysics (ASCA, resolution 3') to determine whether any of the Galactic Ridge X-rays are coming from identifiable sources. They found 163 X-ray sources and identified a third of these with previously known X-ray sources, pulsars, optical stars, or supernova remnants. We have searched the Two Micron All Sky Survey (2MASS) images at the coordinates of their sources and have identified seven of the unidentified ASCA sources as optically obscured star clusters, using a criterion of coincidence in position to within 1'. All but one cluster have associated H II regions, indicating that the clusters contain massive stars. Following is the list of sources, listed by ASCA name, Galactic Coordinates of the cluster, the associated H II region, and any other common name: \newline{AX J144519-5949 -- Cluster 316.801-0.057 -- G316.808-0.037} \newline{AX J151005-5824 -- Cluster 320.256-0.302 -- G320.252-0.332} \newline{AX J162208-5005 -- Cluster and H II region G333.610-0.208} \newline{AX J165922-4234 -- Cluster 343.481-0.044 -- G343.490-0.033} \newline{AX J180857-2004 -- Cluster 10.320-0.150 -- W31B = G10.32-0.15} \newline{AX J184738-0156 -- Cluster 30.768-0.035 -- W43 = G30.8-0.0} \newline{AX J184848-0129 -- Cluster 31.303-0.103 -- IRAS 18462-0133} \newline The last cluster, IRAS 18462-0133, has no radio source near its position and has the appearance of a Globular Cluster in 2MASS images. Its equatorial coordinates are RA 18 48 50.0, Dec -1 29 50. We suggest that Chandra be used to identify the actual stars emitting the X-rays or to determine whether some of the X-rays originate in the diffuse hot gas found in the shocked winds from cluster star outflows.

[Previous] | [Session 45] | [Next]

Bulletin of the American Astronomical Society, 36 #2
© YEAR. The American Astronomical Soceity.