TY - JOUR
T1 - Discovery of a hard X-ray source, SAX J0635 + 0533, in the error box of the gamma-ray source 2EG 0635 + 0521
AU - Kaaret, Philip
AU - Piraino, Santina
AU - Halpern, Jules
AU - Eracleous, Michael
PY - 1999/9/20
Y1 - 1999/9/20
N2 - 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 flux from the source is 1.2 × 10-11 ergs cm-2 s-1 in the 2-10 keV band. The X-ray spectrum is consistent with a simple power-law 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 the 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.
AB - 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 flux from the source is 1.2 × 10-11 ergs cm-2 s-1 in the 2-10 keV band. The X-ray spectrum is consistent with a simple power-law 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 the 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.
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U2 - 10.1086/307711
DO - 10.1086/307711
M3 - Article
AN - SCOPUS:0033588673
SN - 0004-637X
VL - 523
SP - 197
EP - 202
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 PART 1
ER -