A Multi-Wavelength Investigation of the Unidentified Gamma-Ray Source HESS J1708-410

Abstract

We report on recent XMM-Newton observations, archival radio continuum and CO data, and spectral energy distribution (SED) modeling of the unidentified Galactic plane source HESS J1708-410. No significant extended X-ray emission is observed, and we place an upper limit of 3.2 × 10^-13 erg cm^-2 s^-1 in the 2-4 keV range for the region of TeV emission. Molonglo Galactic Plane Survey data are used to place an upper limit of 0.27 Jy at 843 MHz for the source, with a 2.4 GHz limit of 0.4 Jy from the Parkes survey of the southern Galactic plane. ¹²CO (J 1 → 0) data of this region indicates a plausible distance of 3 kpc for HESS J1708-410. SED modeling of both the HESS detection and flux upper limits offer useful constraints on the emission mechanisms, magnetic field, injection spectrum, and ambient medium surrounding this source.