AN X-RAY STUDY OF SUPERNOVA REMNANT N49 AND SOFT GAMMA-RAY REPEATER 0526-66 IN THE LARGE MAGELLANIC CLOUD

作者：Park Sangwook^*; Hughes John P; Slane Patrick O; Burrows David N; Lee Jae Joon; Mori Koji

来源：Astrophysical Journal, 2012, 748(2): 117.

DOI：10.1088/0004-637X/748/2/117

• ISM: individual objects (N49)
• ISM: supernova remnants
• stars: individual (SGR 0526)
• stars: magnetars
• X-rays: ISM
• X-rays: stars

We report on the results from our deep Chandra observation (120 ks) of the supernova remnant (SNR) N49 and soft gamma-ray repeater (SGR) 0526-66 in the Large Magellanic Cloud. We firmly establish the detection of an ejecta %26quot;bullet%26quot; beyond the southwestern boundary of N49. The X-ray spectrum of the bullet is distinguished from that of the main SNR shell, showing significantly enhanced Si and S abundances. We also detect an ejecta feature in the eastern shell, which shows metal overabundances similar to those of the bullet. If N49 was produced by a core-collapse explosion of a massive star, the detected Si-rich ejecta may represent explosive O-burning or incomplete Si-burning products from deep interior of the SN. On the other hand, the observed Si/S abundance ratio in the ejecta may favor Type Ia origin for N49. We refine the Sedov age of N49, tau(Sed) similar to 4800 yr, with the explosion energy E-0 similar to 1.8 x 10(51) erg. Our blackbody (BB) + power law (PL) model for the quiescent X-ray emission from SGR 0526-66 indicates that the PL photon index (Gamma similar to 2.5) is identical to that of PSR 1E1048.1-5937, the well-known candidate transition object between anomalous X-ray pulsars and SGRs. Alternatively, the two-component BB model implies X-ray emission from a small (R similar to 1 km) hot spot(s) (kT similar to 1 keV) in addition to emission from the neutron star%26apos;s cooler surface (R similar to 10 km, kT similar to 0.4 keV). There is a considerable discrepancy in the estimated column toward 0526-66 between BB+PL and BB+BB model fits. Discriminating these spectral models would be crucial to test the long-debated physical association between N49 and 0526-66.

• 出版日期2012-4-1