A Multiwavelength Study of the gamma-Ray Binary Candidate HESS J1832-093

Abstract

We investigate the nature of the unidentified very-high-energy gamma-ray object, HESS J1832-093, in a multiwavelength context. Based on X-ray variability and spectral index (Gamma(X) similar to 1.5), and its broadband spectrum, which was remarkably similar to that of HESS J0632+057-a confirmed gamma-ray binary-HESS J1832-093 has been considered a strong.-ray.binary candidate in previous works. In this work, we provide further evidence for this scenario. We obtained a spectrum of its IR counterpart using Gemini/Flamingo, finding absorption lines that are usually seen in massive stars, in particular O stars. We also obtained a rather steep ATCA spectrum (alpha = - 1.18(-0.88)(+1.04)), which is consistent with alpha-ray binary. Based on spatial-spectral analysis and variability search, we found that 4FGL J1832.9-0913 is possibly associated with SNR.G22.7-0.2 rather than with HESS.J1832-093 only.