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arXiv · 1104.4825

A New Evolutionary Phase of Supernova Remnant 1987A

Sangwook Park·Svetozar A. Zhekov·David N. Burrows·Judith L. Racusin·Daniel Dewey·Richard McCray
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Abstract

We have been monitoring the supernova remnant (SNR) 1987A with {\it Chandra} observations since 1999. Here we report on the latest change in the soft X-ray light curve of SNR 1987A. For the last $\sim$1.5 yr (since day $\sim$8000), the soft X-ray flux has significantly flattened, staying (within uncertainties) at $f_{\rm X}$ $\sim$ 5.7 $\times$ 10$^{-12}$ erg cm$^{-2}$ s$^{-1}$ (corresponding to $L_{\rm X}$ $\sim$ 3.6 $\times$ 10$^{36}$ erg s$^{-1}$) in the 0.5--2 keV band. This remarkable change in the recent soft X-ray light curve suggests that the forward shock is now interacting with a decreasing density structure, after interacting with an increasing density gradient over $\sim$10 yr prior to day $\sim$8000. Possibilities may include the case that the shock is now propagating beyond a density peak of the inner ring. We briefly discuss some possible implications on the nature of the progenitor and the future prospects of our {\it Chandra} monitoring observations.

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Sangwook Park, Svetozar A. Zhekov, David N. Burrows, Judith L. Racusin, Daniel Dewey, Richard McCray. 2011-04-26. A New Evolutionary Phase of Supernova Remnant 1987A. https://doi.org/10.1088/2041-8205%2F733%2F2%2Fl35

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