Chandra observations of galactic supernova remnant Vela Jr.:: A new sample of thin filaments emitting synchrotron X-rays

The Galactic supernova remnant (SNR) Vela Jr. (RX J0852.0-4622, G266.6-1.2) shows sharp filamentary structures on its northwestern edge in the hard X-ray band. The filaments are very smooth and located on the extreme outside edge of the remnant. We measured the averaged scale width of the filaments (w(u) and w(d)) with excellent spatial resolution with Chandra, and they are on the order of the size of the point-spread function of Chandra on the upstream side and 49."5 (36."0 - 88."8) on the downstream side. The spectra of the filaments are very hard and have no linelike structure; they were well reproduced with an absorbed power-law model with Gamma = 2.67 (2.55-2.77) or a SRCUT model with v(roll) = 4.3 (3.4-5.3) x 10(16) Hz under the assumption of p = 0.3. These results imply that the hard X-rays are synchrotron radiation emitted by accelerated electrons, as mentioned previously. Using a correlation between the function B equivalent to v(roll)/w(d)(2) d and the SNR age, we estimated the distance and the age of Vela Jr.: the estimated distance and age are 0.33 (0.26-0.50) kpc and 660 (420-1400) yr, respectively. These results are consistent with previous reports, implying that the B-age relation may be a useful tool for estimating the distance and the age of synchrotron X-ray-emitting SNRs.