[Previous] | [Session 87] | [Next]
W. T. Vestrand, P. R. Wozniak, K.E. McGowan (LANL)
In the past decade, gravitational microlensing of stars in our galaxy has progressed from an interesting theoretical possibility to a practical observational tool for exploring the properties of objects that are difficult to determine any other way. Since for a given geometry the duration scales with the square root of the lens mass, a particularly interesting class of microlensing events is the long duration events. Recently a very exciting long duration event toward the galactic bulge was discovered by the OGLE team and independently identified by the MACHO collaboration. The event, OGLE-1999-BUL-32 has the longest Einstein radius crossing time ever measured---641 days. Straightforward interpretation of this spectacular microlensing event indicates that the lens is either a 150 solar mass black hole at 500 pc or a 30 solar mass black hole at 6 kpc. We present the results of our deep search with the XMM-Newton and Chandra observatories for x-ray emisson from OGLE-1999-BUL-32. We also briefly discuss the constraints that our observations place on models for accretion of the interstellar medium onto isolated, intermediate mass, black holes.
[Previous] | [Session 87] | [Next]
Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.