The Central X-Ray Point Source in Cassiopeia A

Details The Central X-Ray Point Source in Cassiopeia A The Central X-Ray Point Source in Cassiopeia A

2000-01-04

arxiv.org/abs/astro-ph/0001026v3

Astronomy and Astrophysics

Astrophysics

17 pages including 2 figs. To appear in ApJ, Vol. 546 (Jan 10, 2001). Minor revisions per referee. Pulsation limits revised in

Scientific paper

10.1086/318994

The spectacular first light observation by the Chandra X-Ray Observatory revealed an X-ray point source near the center of the 300 yr old Cas A supernova remnant. We present an analysis of the public X-ray spectral and timing data. No coherent pulsations were detected in the Chandra/HRC data. The 3-sigma upper limit on the pulsed fraction is <35% for P>20 ms. The Chandra/ACIS spectrum of the point source may be fit with an ideal blackbody (kT=0.5 keV), or with BB models modified by the presence of a NS atmosphere (kT=0.25-0.35 keV), but the temperature is higher and the inferred emitting area lower than expected for a 300 yr old NS according to standard cooling models. The spectrum may also be fit with a power law model (photon index 2.8-3.6). Both the spectral properties and the timing limits of the point source are inconsistent with a young Crab-like pulsar, but are quite similar to the properties of the anomalous X-ray pulsars. The spectral parameters are also very similar to those of the other radio-quiet X-ray point sources in the supernova remnants Pup A, RCW 103, and PKS 1209-52. Current limits on an optical counterpart for the Cas A point source rule out models that invoke fallback accretion onto a compact object if fallback disk properties are similar to those in quiescent low-mass X-ray binaries. However, the optical limits are marginally consistent with plausible alternative assumptions for a fallback disk. In this case, accreting NS models can explain the X-ray data, but an accreting BH model is not promising.

Affiliated with

Also associated with

No associations

Rating

The Central X-Ray Point Source in Cassiopeia A does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Central X-Ray Point Source in Cassiopeia A, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Central X-Ray Point Source in Cassiopeia A will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-109960