DENTIFICATION CAMPAIGN OF SUPERNOVA REMNANT CANDIDATES IN THE MILKY WAY. I. CHANDRA OBSERVATION OF G308.3-1.4

• Published in: The Astrophysical journal 2012-05, Vol.750 (1), p.1-9
• Main Authors: Hui, C Y, Seo, K A, Huang, R H H, TREPL, L, Woo, Y J, Lu, T-N, Kong, A K H, Walter, F M
• Format: Article
• Language: English
• Subjects: Band spectra; Lists; Neutron stars; Observatories; Searching; Spectral energy distribution; Supernova remnants; X-rays
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/750/1/7

ROSAT all-sky survey data have provided another window in which to search for supernova remnants (SNRs). In re-examining this data archive, a list of unidentified extended X-ray objects have been suggested as promising SNR candidates. However, most of these targets have not yet been fully explored by state-of-the-art X-ray observatories. To select a pilot target for a long-term identification campaign, we observed the brightest candidate, G308.3-1.4, with the Chandra X-ray Observatory. An incomplete shell-like X-ray structure that is well correlated with the radio shell emission at 843 MHz has been revealed. The X-ray spectrum suggests the presence of a shock-heated plasma. All these evidences confirm G308.3-1.4 as an SNR. The brightest X-ray point source detected in this field of view is also the one located closest to the geometrical center of G308.3-1.4, which has a soft spectrum. The intriguing temporal variability and the identification of the optical/infrared counterpart rule out the possibility of an isolated neutron star. On the other hand, the spectral energy distribution from the K sub(s) band to the R band suggests a late-type star. Together with a putative periodicity of ~1.4 hr, the interesting excesses in the V and B bands and in H alpha suggest that this source is a promising candidate for a compact binary that survived a supernova explosion.