The Swift Galactic Plane Survey
Swift J134745.7-621411: A New Galactic SNR
A Candidate SNR Discovered in the Swift Galactic Plane Survey (Atel #3963, erratum #3982)
Mark Reynolds, Jon Miller, Dipankar Maitra, Kayhan Gultekin (UofM); Neil Gehrels (NASA/GSFC); Jamie Kennea, Mike Siegel, Jonathan Gelbord (PSU); Paul Kuin (MSSL) The Swift galactic plane survey team (SGPS) report the detection of a new extended X-ray source. The source was discovered in a 1.4 ks XRT exposure on 2011 October 30th. Characterizing the new source with a circle, we measure the following coordinates for the source center: 13:47:45.7, -62:14:11 (J2000), or l,b = 309.43932, -0.078391, with a radial extent of 100 arc-seconds. We do not detect any flux at energies below 2 keV, consistent with the large column density in the direction of this source (nh = 1.7e22 cm^-2). Within this circular region we measure a count rate of (2.4+/-0.5)e-2 ct/s. Assuming a power-law spectral shape with a spectral index of 1.8, implies an integrated luminosity of 3.9e32 erg/s (d/1 kpc) in the 2 - 10 keV band. Inspection of available archival data reveals a counterpart to the X-ray source at radio wavelengths, MGPS J134743-621354 with a measured flux density of 64.8+/-2.7 mJy (Murphy et al., 2007). A counterpart to the X-ray source is not detected at UV/opt/IR wavelengths, see the image at the link below for details. Based on the extended nature of the X-ray source and the presence of a radio counterpart, we classify this source as a new galactic supernova remnant: Swift J134745.7-621411. This is the second SNR discovered by the SGPS (see atel #3415). Follow-up observations to confirm the nature of this source are encouraged.
Multi-wavelength images of the field containing the newly discovered supernova remnant Swift J134745.7-621411. The images are from left to right (top row) XRT 2 - 10 keV, UVOT UVM2, DSS2 red, DSS2 IR, (middle row) 2MASS J, 2MASS H, 2MASS K, GLIMPSE 4.5 micron, (bottom row) GLIMPSE 8 micron, MIPSGAL 24 micron, MGPS 843 MHz. The candidate supernova remnant, indicated by the green circle (radius 100 arcsec), is clearly detected in hard X-rays, with a counterpart at radio wavelengths alone.
The Swift Galactic Plane Survey is tiling 240 square degrees of the Galactic plane, from -60 < l < 60 and -1 < b < 1. Each exposure is approximately 500 seconds in duration, and includes simultaneous XRT (0.3-10 keV) and UVOT/UVM2 images (2000-2500 Angstroms). All values reported herein should be considered as preliminary, a comprehensive analysis will be presented in Reynolds et al. (2012) in prep.