Identification of the central compact object in the young supernova remnant 1E

Oxygen-rich young supernova remnants ¹ are valuable objects for probing the outcome of nucleosynthetic processes in massive stars, as well as the physics of supernova explosions. Observed within a few thousand years after the supernova explosion ², these systems contain fast-moving oxygen-rich and hydrogen-poor filaments visible at optical wavelengths: fragments of the progenitor's interior expelled at a few thousand kilometres per second during the supernova explosion. Here we report the identification of the compact object in the supernova remnant 1E 0102.2-7219 in reprocessed Chandra X-ray Observatory data, enabled by the discovery of a ring-shaped structure visible primarily in optical recombination lines of Ne i and O i. The optical ring has a radius of (2.10 ± 0.35)″ â‰i (0.63 ± 0.11) pc, and is expanding at a velocity of $$90.{5}-{-30}^{+40}$$ 90. 5-30 + 40 km s^-1. It surrounds an X-ray point source with an intrinsic X-ray luminosity L _i (1.2-2.0 keV)=(1.4 ± 0.2) × 10³³ erg s^-1. The energy distribution of the source indicates that this object is an isolated neutron star: A central compact object akin to those present in the Cas A ^3-5 and Pup A ⁶ supernova remnants, and the first of its kind to be identified outside of our Galaxy.