X-ray Evolution of SN 1987A

TL;DR

Over 20 years of X-ray observations of SN 1987A reveal shock interactions with the inner ring, showing thermal emission with elemental overabundances and differing lightcurve slopes across energy bands.

Contribution

This study provides a comprehensive analysis of two decades of X-ray data, highlighting the evolution of shock interactions and elemental abundances in SN 1987A.

Findings

Shock wave interacts strongly with the inner ring.

Inner ring shows overabundance of Si and S.

X-ray lightcurves differ significantly in slope.

Abstract

The X-ray observations of SN 1987A over the previous 20 years have seen the emergence of soft X-rays from the interaction of the explosion shock wave with the ambient medium. This shock wave is now interacting strongly with the inner ring and might have passed already the highest density regions. The emission can be described by thermal models with two temperatures, with perhaps some but little change over time. Relative to the elemental abundances prevailing in the LMC the inner ring shows an overabundance of Si and S compared to the lighter elements and Fe, which suggests that the ring consists of highly processed matter dredged up in a binary merger event well before the explosion. The X-ray lightcurves between 0.5--2 keV and 3--10 keV differ significantly in slope, with the latter being much flatter but very similar to the radio light curve.