Nature of the compact object in HESS J1832-093

Determine the nature of the compact object in the gamma-ray binary HESS J1832−093, whose X-ray counterpart is XMMU J183245−0921539, given that near-infrared spectroscopy identifies an O6 V stellar companion but the type of the compact object remains unknown.

Background

The paper targets two X-ray point sources: CXOU J201609.2+371110 in SNR CTB 87 and XMMU J183245−0921539 near SNR G22.7−0.2, the latter being the X-ray counterpart to the gamma-ray binary HESS J1832−093. While near-infrared spectroscopy has classified the companion star as an O6 V star, the compact object’s identity has not been established.

Motivated by indications that the compact object may be a pulsar, the authors conducted a FAST search for radio pulsations toward XMMU J183245−0921539 but did not detect any signal, leaving the fundamental nature of the compact object unresolved.