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 10^33 D(3.5)^2 erg/s (where D(3.5) is the
distance in units of 3.5 kpc), with an electron density n_e 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 10^34 D(4.8)^2
erg/s (where D(4.8) is the distance in units of 4.8 kpc), with an electron
density n_e 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.Comment: 30 pages using emulateapj, 16 figures with quality reduced for
astro-ph only. The original version with high-resolution figures can be
downloaded from:
http://www.physics.umanitoba.ca/~samar/astro-ph/G85s-ms09102007.pdf To appear
in ApJ (Jan 20 2008 issue, v673, n1