090212

3HWC J1928+178 is one of the brightest Galactic gamma-ray sources detected by HAWC up to virgul56 TeV and potentially associated with one of the dozen PeVatron sources discovered by LHAASO. Given no apparent pulsar wind nebula or supernova remnant in the vicinity the HAWC source still remains unidentified. Recent X-ray and TeV observations as well as our multi-wavelength SED study pinned down the HAWC source to be either a PeVatron pulsar wind nebula TeV halo or TeV gamma-ray binary. In particular we found two X-ray counterpart candidates of the HAWC source - a variable X-ray source with a massive companion and putative diffuse X-ray emission. We propose a follow-up XMM observation of the X-ray counterpart candidates for determining the nature of this enigmatic HAWC source. [truncated! Please see actual data for full text]