# Chandra Observations of Supernova 1987A

## TL;DR

This paper reviews Chandra X-ray observations of Supernova 1987A from 1999 to 2007, revealing how the blast wave interacts with the surrounding dense circumstellar medium, causing brightening and changes in expansion velocity.

## Contribution

It provides new insights into the evolution of SN 1987A's X-ray emission and shock interaction with the circumstellar medium based on recent Chandra data.

## Key findings

- X-ray luminosity increased to ~2.4 x 10^{36} erg/s by 2007
- X-ray emission characterized by two-component shock model with temperatures ~0.3 and 2 keV
- Expansion velocity slowed to ~1400 km/s from ~6000 km/s

## Abstract

We have been monitoring Supernova (SN) 1987A with {\it Chandra X-Ray Observatory} since 1999. We present a review of previous results from our {\it Chandra} observations, and some preliminary results from new {\it Chandra} data obtained in 2006 and 2007. High resolution imaging and spectroscopic studies of SN 1987A with {\it Chandra} reveal that X-ray emission of SN 1987A originates from the hot gas heated by interaction of the blast wave with the ring-like dense circumstellar medium (CSM) that was produced by the massive progenitor's equatorial stellar winds before the SN explosion. The blast wave is now sweeping through dense CSM all around the inner ring, and thus SN 1987A is rapidly brightening in soft X-rays. At the age of 20 yr (as of 2007 January), X-ray luminosity of SN 1987A is $L_{\rm X}$ $\sim$ 2.4 $\times$ 10$^{36}$ ergs s$^{-1}$ in the 0.5$-$10 keV band. X-ray emission is described by two-component plane shock model with electron temperatures of $kT$ $\sim$ 0.3 and 2 keV. As the shock front interacts with dense CSM all around the inner ring, the X-ray remnant is now expanding at a much slower rate of $v$ $\sim$ 1400 km s$^{-1}$ than it was until 2004 ($v$ $\sim$ 6000 km s$^{-1}$).