Related papers: Low-Frequency Radio Absorption in Cassiopeia A
Cassiopeia A (Cas A) supernova remnant shows strong radiation from radio to gamma-ray bands. The mechanism of gamma-ray radiation in Cas A and its possible contribution to PeV cosmic rays are still under debate. The X-ray imaging reveals an…
We report the detection of carbon monoxide (CO) emission from the young supernova remnant Cassiopeia A (Cas A) at wavelengths corresponding to the fundamental vibrational mode at 4.65 micron. We obtained AKARI Infrared Camera spectra…
We present three-dimensional kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey…
We present the analysis of 21 bright X-ray knots in the Cassiopeia A supernova remnant from observations spanning 10 yr. We performed a comprehensive set of measurements to reveal the kinematic and thermal state of the plasma in each knot,…
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 present spectroscopy of the supernova remnant Cassiopeia A (Cas A) observed at infrared wavelengths from 10 - 40 micron with the Spitzer Space Telescope and at millimeter wavelengths in 12CO and 13CO J = 2 - 1 (230 and 220 GHz) with the…
Recently, the GeV--sub-PeV spectrum of supernova remnant (SNR) Cassiopeia A (Cas A), one of the youngest and most well-studied SNRs in our Galaxy, has been updated by observations of Fermi-LAT and LHAASO. We revisit Cas A with our previous…
We investigate the effect of the circumstellar medium density profile on the X-ray emission from outer ejecta knots in the Cassiopeia A supernova remnant using the 1 Ms Chandra observation. The spectra of a number of radial series of ejecta…
Tycho's SNR is the remnant of the type Ia supernova explosion SN1572. In this work we present new low-frequency radio observations with the LOFAR Low-Band and High-Band Antennae, centred at 58 MHz and 143 MHz, and with an angular resolution…
The ejected material at the binary neutron star merger GW 170817 was confirmed as a kilonova by UV, optical, and IR observations. This event provides a unique opportunity to investigate the particle acceleration at a mildly relativistic…
Long-term measurements of the radio flux density of Cassiopeia A relative to Cygnus A have been carried out at 927 and 151.5 MHz. It was found the following mean secular decrease rates of the radio emission of Cassiopeia A: $(0.72\pm 0.03)%…
We present new Chandra ACIS-S3 observations of Cassiopeia A which, when combined with earlier ACIS-S3 observations, show evidence for a steady ~ 1.5-2%/yr decline in the 4.2-6.0 keV X-ray emission between the years 2000 and 2010. The…
The observed shock wave positions and expansion in Cas A can be interpreted in a model of supernova interaction with a freely expanding stellar wind with a mass loss rate of ~3e-5 Msun/yr for a wind velocity of 10 km/s. The wind was…
We present a study of carbon radio recombination lines towards Cassiopeia A using LOFAR observations in the frequency range 10-33 MHz. Individual carbon $\alpha$ lines are detected in absorption against the continuum at frequencies as low…
We report the discovery of polarized flux at 2.2 micron from the bright shell of the approximately 320 year old supernova remnant Cas A. The fractional polarizations are comparable at 6 cm and 2.2 micron, and the polarization angles are…
Supernova remnants (SNRs) provide crucial information of yet poorly understood mechanism of supernova explosion. Here we present XRISM high-resolution spectroscopy of the intermediate-mass-element (IME) ejecta in the SNR Cas A to determine…
We present the results of extinction measurements toward the main ejecta shell of the Cassiopeia A supernova (SN) remnant using the flux ratios between the two near-infrared (NIR) [Fe II] lines at 1.26 and 1.64 $\mu {\rm m}$. We find a…
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.…
Recent discovery of the year-scale variability in the synchrotron X-ray emission of the supernova remnant (SNR) RX J1713.7-3946 has initiated our study of multi-epoch X-ray images and spectra of the young SNR Cassiopeia A based on the…
Ground-based optical spectra and Hubble Space Telescope images of ten core-collapse supernovae (CCSNe) obtained several years to decades after outburst are analyzed with the aim of understanding the general properties of their late-time…