Related papers: Small-Scale X-ray Variability in the Cassiopeia A …
We report 1405 MHz measurements of the flux density of the approximately 320 year old supernova remnant Cassiopeia A, relative to the flux density of Cygnus A, made between 1995 and 1999. When compared to measurements made between 1957 and…
The cooling rate of young neutron stars gives direct insight into their internal makeup. Although the temperatures of several young neutron stars have been measured, until now a young neutron star has never been observed to decrease in…
gamma Cassiopeiae (gCas) is a B0.5e star with peculiar X-ray emission properties and yet the prototype of its own small class. In this paper we examine the X-ray spectra for a 2004 XMM-Newton observation and a previously published 2001…
We present X-ray proper-motion measurements of the forward shock and reverse-shocked ejecta in Tycho's supernova remnant, based on three sets of archival Chandra data taken in 2000, 2003, and 2007. We find that the proper motion of the edge…
We present the 2-60 keV spectrum of the supernova remnant Cassiopeia A measured using the Proportional Counter Array and the High Energy X-ray Timing Experiment on the Rossi X-ray Timing Explorer satellite. In addition to the previously…
We present results of a recent Chandra X-ray Observatory observation of the central compact object (CCO) in the supernova remnant Cassiopeia A. This observation was obtained in an instrumental configuration that combines a high spatial…
We compare the diversity of spectral line velocities in a large sample of type IIb supernovae (SNe IIb) with the expected asphericity in the explosion, as measured from the light echoes of Cassiopeia A (Cas A), which was a historical…
We continue monitoring supernova remnant (SNR) 1987A with the {\it Chandra X-ray Observatory}. As of 2004 January, bright X-ray spots in the northwest and the southwest are now evident in addition to the bright eastern ring. The overall…
We compare the radio and soft X-ray brightness as a function of position within the young supernova remnant Cassiopeia A. A moderately strong correlation (r = 0.7) was found between the X-ray emission (corrected for interstellar absorption)…
We present new reddening measurements towards the young supernova remnant Cassiopeia A, using two techniques not previously applied to this object. Our observations of the near-infrared [Fe II] 1.257 micron and 1.644 micron lines show the…
We report results from 13 years of Chandra monitoring of nonthermal X-ray emission from the youngest Galactic supernova remnant G1.9+0.3, the only remnant known to be increasing in brightness. We confirm the spatially-integrated flux…
We present proper motions for 21 bright main shell and 17 faint, higher-velocity, outer ejecta knots in the Cas A supernova remnant and use them to derive new estimates for the remnant's expansion center and age. Our study included 1951 -…
Young supernova remnants (SNRs) are believed to be the origin of energetic cosmic rays (CRs) below the "knee" of their spectrum at $\sim3$ petaelectronvolt (PeV, $10^{15}$ eV). Nevertheless, the precise location, duration, and operation of…
We present multi-epoch Ks band imaging of the supernova remnant Cassiopeia A (Cas A). The morphology of the emission in this band is generally diffuse and filamentary, consistent with synchrotron radiation observed at radio wavelengths.…
We report measurements of X-ray expansion of the youngest Galactic supernova remnant, G1.9+0.3, using Chandra observations in 2007, 2009, and 2011. The measured rates strongly deviate from uniform expansion, decreasing radially by about 60%…
We present X-ray analysis of the ejecta of supernova remnant G350.1$-$0.3 observed with Chandra and Suzaku, and clarify the ejecta's kinematics over a decade and obtain a new observational clue to understanding the origin of the asymmetric…
The nonlinear kinetic model of cosmic ray (CR) acceleration in supernova remnants (SNRs) is used to describe the relevant properties of Cassiopeia A (Cas A). In order to reproduce the SNR's observed size, expansion rate and thermal X-ray…
The youngest Galactic supernova remnant (SNR) G1.9+0.3, produced by a (probable) SN Ia that exploded $\sim 1900$ CE, is strongly asymmetric at radio wavelengths, much brighter in the north, but bilaterally symmetric in X-rays. We present…
We propose a model for the hard X-ray (> 10 keV) emission observed from the supernova remnant Cas A. Lower hybrid waves are generated in strong (mG) magnetic fields, generally believed to reside in this remnant, by shocks reflected from…
We report the first results from deep X-ray observations of the SNR 1987A with the Chandra LETG. Temperatures inferred from line ratios range from 0.1 - 2 keV and increase with ionization potential. Expansion velocities inferred from X-ray…