Nature of the Unidentified TeV Source HESS J1614–518 Revealed by Suzaku and XMM-Newton Observations

摘要

We report new results concerning HESS J1614–518, which exhibits two regions with intense γ-ray emission. The south and center regions of HESS J1614–518 were observed with Suzaku in 2008, while the north region with the 1st brightest peak was observed in 2006. No X-ray counterpart is found at the 2nd brightest peak; the upper limit of the X-ray flux is estimated as 1.6 × 10~(?13) erg cm~(?2) s~(?1) in the 2–10 keV band. A previously-known soft X-ray source, Suzaku J1614–5152, is detected at the center of HESS J1614–518. Analyzing the XMM-Newton archival data, we reveal that Suzaku J1614–5152 consists of multiple point sources. The X-ray spectrum of the brightest point source, XMMU J161406.0–515225, could be described by a power-law model with the photon index Г = 5.2_(-0.5)~(+0.6) or a blackbody model with the temperature kT = 0.38_(-0.04)~(+0.04) keV. In the blackbody model, the estimated column density N_H = 1.1_(-0.2)~(+0.3) × 10~(22) cm~(-2) is almost the same as that of the hard extended X-ray emission in Suzaku J1614–5141, spatially coincident with the 1st peak position. In this case, XMMU J161406.0–515225 may be physically related to Suzaku J1614–5141 and HESS J1614–518.