2009/12/25 by Yoshitomo Maeda, Y. Maeda, Yasunobu Uchiyama +55 · 2 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Bremsstrahlung #Cassiopeia A #Emission spectrum #Gamma-ray bursts and supernovae #Ionization #Plasma #Spectral line #Spectroscopy #Supernova #Supernova remnant #astro-ph.HE
paper · pdf · doi:10.1093/pasj/61.6.1217
Publ. Astron. Soc. Japan 61, pp.1217-1228 (2009)
openalex publication_date 2009/12/25 · arxiv created 2009/12/26 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract Suzaku X-ray observations of a young supernova remnant, Cassiopeia A, were carried out. K-shell transition lines from highly ionized ions of various elements were detected, including Chromium (Cr-Kα at 5.61 keV). The X-ray continuum spectra were modeled in the 3.4–40 keV band, summed over the entire remnant, and were fitted with a simplest combination of the thermal bremsstrahlung and the non-thermal cut-off power-law models. The spectral fits with this assumption indicate that the continuum emission is likely to be dominated by non-thermal emission with a cut-off energy at > 1 keV. The thermal-to-nonthermal fraction of the continuum flux in the 4–10 keV band is best estimated as ∼ 0.1. Non-thermal-dominated continuum images in the 4–14 keV band were made. The peak of the non-thermal X-rays appears at the western part. The peak position of the TeV γ-rays measured with HEGRA and MAGIC is also shifted at the western part with the 1-sigma confidence. Since the location of the X-ray continuum emission was known to be presumably identified with the reverse shock region, the possible keV–TeV correlations give a hint that the accelerated multi-TeV hadrons in Cassiopeia A are dominated by heavy elements in the reverse shock region.