2015/04/02 by F. J. Lu, M. Y. Ge, S. J. Zheng +3 · 4 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Ejecta #Emission spectrum #Gamma-ray bursts and supernovae #Ionization #Line (geometry) #Near-Earth supernova #RADIUS #Supernova #Supernova remnant #astro-ph.HE
paper · pdf · doi:10.1088/0004-637x/805/2/142
published in The Astrophysical Journal 805(2), 142 (IOP Publishing) · 22 pages, 8 figures, accepted by ApJ
arxiv created 2015/04/02 · openalex publication_date 2015/05/28 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Thermal X-ray emission from young supernova remnants (SNRs) is usually dominated by the emission lines of the supernova ejecta, which are widely believed to be crossed and thus heated by the inward-propagating reverse shock (RS). Previous works using X-ray imaging data have shown that the ejecta are heated by the RS by locating the peak emission region of the most recently ionized matter, which is found to be well separated toward the inside from the outermost boundary. Here we report the discovery of a systematic increase of the Sulfur (S) to Silicon (Si) K α line flux ratio with radius in Tycho's SNR. This allows us, for the first time, to present continuous radial profiles of the ionization age and, furthermore, the elapsed ionization time since the onset of the ionization, which gives the history of the propagation of the ionization front into the SNR ejecta.