The talks are in the same order as the Program Schedule.
Bauer, Franz - A Legacy Study of Stellar Lifecycles in the Galactic Center
Williams, Benjamin - The Chandra ACIS Survey of M33 (ChASeM33)
Swartz, Douglas - Do Ultraluminous X-Ray Sources Exist in Dwarf Galaxies?
Franz Bauer (Columbia University)
We report on a multi-wavelength project to study the life-cycles of massive stars in the central 300 pc of the Galaxy. The centerpiece of the project is 680 ks of deep (40 ks each) Chandra observations, which we compare to radio maps at 90, 20, and 1.4 cm taken with the VLA; mid-infrared images at 8.0, 5.8, 4.5 and 3.6 micron taken with Spitzer; and J,H,K images from the SIRIUS camera on the IRSF. The images reveal a wide variety of diffuse phenomena, including iron fluorescence from molecular clouds that have reflected past outbursts of the supermassive black hole Sgr A*, thermal X-ray emission from young supernova remnants, non-thermal X-ray emission from several of the mysterious radio-emitting filaments, and shocks produced by stellar sources at the centers of HII regions. We also report the results of a campaign to identify the infrared counterparts to X-ray sources, using spectra taken with a number of 3-5 m class telescopes. These spectra have revealed several dozen young, massive colliding-wind binaries and high-mass X-ray binaries.
Benjamin Williams (University of Washington) , The ChASeM33 Team
We have performed a survey of M33 covering 7 ACIS-I fields, each with 200 ks of exposure. These data provide the deepest and highest resolution X-ray data for M33 available out to a projected galactocentric distance of 4 kpc. The data contain several hundred individual X-ray sources to a limiting luminosity of 1035 erg/s (0.35-8.0 keV) as well as soft diffuse emission from the hot interstellar medium. The observations were spread over multiple epochs to allow variability studies. We have performed detailed analysis on several point sources of interest, including eclipsing X-ray binaries and transients. We have also completed analysis on several diffuse sources, including supernova remnants and H II regions. An overview of the data, the results of these first detailed studies, and our plan for future work will be presented. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number G06-7073A issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060.
Douglas Swartz (NASA/MSFC)
A thorough search for Ultraluminous X-ray source candidates within a distance of approximately 8 Mpc is made. The search spatially matches potential ULXs detected in X-ray images or cataloged in the literature with galaxies tabulated in the Catalog of Neighboring Galaxies compiled by Karachentsev et al. (2004). The specific ULX rate (occurrence rate per unit mass) is found to be a decreasing function of host galaxy mass for host masses above
M
. There is too little mass in galaxies below Mdg to determine their ULX content in a statistically meaningful way. Possible reasons for and implications of an increase in specific ULX rate with decreasing galaxy mass are presented.