Exploring a SNR/molecular cloud association within HESS J1745–303

Abstract

Aims. HESS J1745-303 is an extended, unidentified VHE (very high energy) gamma-ray source discovered using HESS in the Galactic Plane Survey. Since no obvious counterpart has previously been found in longer-wavelength data, the processes that power the VHE emission are not well understood.

Methods. Combining the latest VHE data with recent XMM-Newton observations and a variety of source catalogs and lower-energy survey data, we attempt to match (from an energetic and positional standpoint) the various parts of the emission of HESS J1745-303 with possible candidates.

Results. Though no single counterpart is found to fully explain the VHE emission, we postulate that at least a fraction of the VHE source may be explained by a supernova-remnant/molecular-cloud association and/or a high-spin-down-flux pulsar.

Auxiliary informations

Spectrum

Full spectrum (Figure 2):

E E^2 dN/dE error_low error_up
(TeV) (erg/cm2/s)
0.34603 1.01211e-11 1.35747e-12 1.36563e-12
0.60481 6.35885e-12 8.4088e-13 8.4719e-13
1.06183 4.30832e-12 6.8007e-13 6.86648e-13
1.87934 2.66866e-12 6.48719e-13 6.57234e-13
3.32625 2.07955e-12 7.14742e-13 7.26675e-13
7.69408 7.57597e-13 5.73542e-13 5.84117e-13
23.9738 5.68098e-13 6.42779e-13 6.724e-13

Region A points:

E E^2 dN/dE error_low error_up
(TeV) (erg/cm2/s)
0.396617 1.15883e-12 2.43335e-13 2.46624e-13
0.764819 8.67428e-13 1.63794e-13 1.66847e-13
1.48272 7.09538e-13 1.45753e-13 1.49513e-13
2.87831 3.77066e-13 1.54034e-13 1.59562e-13
5.60273 1.03685e-13 1.69734e-13 1.78762e-13
10.9058 -3.97382e-14 1.88474e-13 2.04455e-13
21.2576 -1.2227e-13 1.74625e-13 2.04774e-13

FITS images

Figure 1
[excess]
[significance]