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 temperatures of \sim 0.28 keV and \sim 2.8 ^ { +0.7 } _ { -1.0 } keV , with perhaps some but little change over time .
High resolution spectroscopy reveals a large variety of shock velocities ranging from a few hundred to many thousand km s ^ { -1 } .
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 .