We report on the results from the analysis of our 114 ks Chandra HETGS observation of the Galactic core-collapse supernova remnant G292.0+1.8 .
To probe the 3D structure of the clumpy X-ray emitting ejecta material in this remnant , we measured Doppler shifts in emission lines from metal-rich ejecta knots projected at different radial distances from the expansion center .
We estimate radial velocities of ejecta knots in the range of -2300 \lesssim v _ { r } \lesssim 1400 km s ^ { -1 } .
The distribution of ejecta knots in velocity vs. projected-radius space suggests an expanding ejecta shell with a projected angular thickness of \sim 90 \arcsec ( corresponding to \sim 3 pc at d = 6 kpc ) .
Based on this geometrical distribution of the ejecta knots , we estimate the location of the reverse shock approximately at the distance of \sim 4 pc from the center of the supernova remnant , putting it in close proximity to the outer boundary of the radio pulsar wind nebula .
Based on our observed remnant dynamics and the standard explosion energy of 10 ^ { 51 } erg , we estimate the total ejecta mass to be \lesssim 8 M _ { \astrosun } , and we propose an upper limit of \lesssim 35 M _ { \astrosun } on the progenitor ’ s mass .