2007/06/18 by T. J. Gaetz, Terrance J. Gaetz, William P. Blair +19 · 1 citation
Physics and Astronomy · #Acis #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Extinction (optical mineralogy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Ionization #Luminosity #Optics #Physics #Spectroscopy #Supernova #Supernova remnant #X-ray #astro-ph
paper · pdf · doi:10.1086/518397
published as Astrophys.J.663:234-243,2007 · 27 pages, 6 figures (3 color). ApJ (in press)
arxiv created 2007/06/18 · openalex publication_date 2007/06/22 · arxiv updated 2011/02/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present and interpret new X-ray data for M33SNR 21, the brightest X-ray supernova remnant (SNR) in M33. The SNR is in seen projection against (and appears to be interacting with) the bright H II region NGC 592. Data for this source were obtained as part of the Chandra ACIS Survey of M33 (ChASeM33) Very Large Project. The nearly on-axis Chandra data resolve the SNR into a ~5'' diameter (20 pc at our assumed M33 distance of 817 ± 58 kpc) slightly elliptical shell. The shell is brighter in the east, which suggests that it is encountering higher density material in that direction. The optical emission is coextensive with the X-ray shell in the north, but extends well beyond the X-ray rim in the southwest. Modeling the X-ray spectrum with an absorbed sedov model yields a shock temperature of 0.46 keV, with an ionization timescale of n e t = 2.1 × 10 12 cm -3 s and half-solar abundances (0.45 ). Assuming Sedov dynamics gives an average preshock H density of 1.7 ± 0.3 cm -3 . The dynamical age estimate is 6500 ± 600 yr, while the best-fit n e t value and derived n e gives 8200 ± 1700 yr; the weighted mean of the age estimates is 6700 ± 600 yr. We estimate an X-ray luminosity (0.25-4.5 keV) of (1.2 ± 0.2) × 10 37 ergs s -1 (absorbed), and (1.7 ± 0.3) × 10 37 ergs s -1 (unabsorbed), in good agreement with the recent XMM-Newton determination. No significant excess hard emission was detected; the luminosity ≲1.2 × 10 35 ergs s -1 (2-8 keV) for any hard point source.