We discuss the X-ray emission observed from Supernova Remnant 1987A with the Chandra X-ray Observatory .
We analyze a high resolution spectrum obtained in 1999 October with the high energy transmission grating ( HETG ) .
From this spectrum we measure the strengths and an average profile of the observed X-ray lines .
We also analyze a high signal-to-noise ratio CCD spectrum obtained in 2000 December .
The good statistics ( \approx 9250 counts ) of this spectrum and the high spatial resolution provided by the telescope allow us to perform spectroscopic analyses of different regions of the remnant .

We discuss the relevant shock physics that can explain the observed X-ray emission .
The X-ray spectra are well fit by plane parallel shock models with post-shock electron temperatures of \approx 2.6 \mbox { keV } and ionization ages of \approx 6 \times 10 ^ { 10 } cm ^ { -3 } s. The combined X-ray line profile has a FWHM of \approx 5000 \mbox { km s } ^ { -1 } , indicating a blast wave speed of \approx 3500 \mbox { km s } ^ { -1 } .
At this speed , plasma with a mean post-shock temperature of \approx 17 \mbox { keV } is produced .
This is direct evidence for incomplete electron-ion temperature equilibration behind the shock .
Assuming this shock temperature , we constrain the amount of collisionless electron heating at the shock front at T _ { e 0 } / T _ { s } = 0.11 ^ { +0.02 } _ { -0.01 } .
We find that the plasma has low metallicity ( abundances are \approx 0.1 – 0.4 solar ) and is nitrogen enriched ( N/O \approx 0.8 by number ) , similar to abundances found for the equatorial ring .

Analysis of the spectra from different regions of the remnant reveals slight differences in the parameters of the emitting plasma .
The plasma is cooler near the optical Spot 1 ( at position angle \approx 30 ^ { \circ } ) and in the eastern half of the remnant , where the bright optical spots are found , than in the western half , consistent with the presence of slower ( \approx 500 \mbox { km s } ^ { -1 } ) shocks entering denser ring material .
There is an overall flux asymmetry between the two halves , with the eastern half being 15 – 50 % brighter ( depending on how the center of the remnant is defined ) .
However , our spectroscopic analysis shows that < 5 \% of the overall X-ray emission could come from a slow shock component .
Therefore the flux asymmetry can not fully be due to X-rays produced by the blast wave entering the ring , but rather indicates an asymmetry in the global interaction with the circumstellar material interior to the ring .