XMM-Newton, Chandra, and CGPS observations of the Supernova Remnants G85.4+0.7 and G85.9-0.6
Abstract
We present an XMM-Newton detection of two low radio surface brightness SNRs, G85.4+0.7 and G85.9-0.6, discovered with the Canadian Galactic Plane Survey (CGPS). High-resolution XMM-Newton images revealing the morphology of the diffuse emission, as well as discrete point sources, are presented and correlated with radio and Chandra images. The new data also permit a spectroscopic analysis of the diffuse emission regions, and a spectroscopic and timing analysis of the point sources. Distances have been determined from HI and CO data to be 3.5 +/- 1.0 kpc for SNR G85.4+0.7 and 4.8 +/- 1.6 kpc for SNR G85.9-0.6. The SNR G85.4+0.7 is found to have a temperature of ~12-13 MK and a 0.5-2.5 keV luminosity of ~1-4 x 1033 D(3.5)2 erg/s (where D(3.5) is the distance in units of 3.5 kpc), with an electron density ne of ~0.07-0.16(fD(3.5))-1/2 cm-3 (where f is the volume filling factor), and a shock age of ~9-49(fD(3.5))1/2 kyr. The SNR G85.9-0.6 is found to have a temperature of ~15-19 MK and a 0.5-2.5 keV luminosity of ~1-4 x 1034 D(4.8)2 erg/s (where D(4.8) is the distance in units of 4.8 kpc), with an electron density ne of ~0.04-0.10(fD(4.8))-1/2 cm-3 and a shock age of ~12-42(fD(4.8))1/2 kyr. Based on the data presented here, none of the point sources appears to be the neutron star associated with either SNR.