Discovery of a Hard X-Ray Source, SAX J0635+0533, in the Error
Box of the Gamma-Ray Source 2EG 0635+0521
P. Kaaret, S. Piraino
We have discovered an x-ray source, SAX J0635+0533, with a hard
spectrum within the error box of the GeV gamma-ray source in
Monoceros, 2EG J0635+0521. The unabsorbed x-ray flux is
1.2 ×10-11 erg cm-2 s-1 in the 2-10 keV
band. The x-ray spectrum is consistent with a simple powerlaw model
with absorption. The photon index is 1.50 ±0.08 and we detect
emission out to 40 keV. Optical observations identify a counterpart
with a V-magnitude of 12.8. The counterpart has broad emission lines
and the colors of an early B type star. If identification of
the x-ray/optical source with the gamma-ray source is correct, then
the source would be a gamma-ray emitting x-ray binary.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:19.