Chandra HETG Spectra of SN 1987A at 20 years
Abstract
We have undertaken deep, high-resolution observations of SN 1987A at ~20 years after its explosion with the Chandra HETG and LETG spectrometers. Here we present the HETG X-ray spectra of SN 1987A having unprecedented spectral resolution and signal-to-noise in the 6 A to 20 A bandpass, which includes the H-like and He-like lines of Si, Mg, Ne, as well as O VIII lines and bright Fe XVII lines. In joint analysis with LETG data, we find that there has been a significant decrease from 2004 to 2007 in the average temperature of the highest temperature component of the shocked-plasma emission. Model fitting of the profiles of individual HETG lines yields bulk kinematic velocities of the higher-Z ions, Mg and Si, that are significantly lower than those inferred from the LETG 2004 observations.
Keywords
Cite
@article{arxiv.0802.2340,
title = {Chandra HETG Spectra of SN 1987A at 20 years},
author = {D. Dewey and S. A. Zhekov and R. McCray and C. R. Canizares},
journal= {arXiv preprint arXiv:0802.2340},
year = {2009}
}
Comments
12 pages, 5 figures, 1 table; accepted for publication in ApJ Letters