Analysis of Gradient Profiles and Morphology of the Vela Jr. Supernova Remnant

We present the study of gradient profiles of the Vela Jr. northwestern rim in X-ray emission and the morphology of this supernova remnant in various spectral ranges of electromagnetic radiation to estimate the distance to the object and its age. This work involves radiation intensity spatial distributions for the northwestern rim of the supernova remnant RX J0852.0–4622 in the X-ray energy range, 1000.0–2000.0 eV, obtained from measurements of the EPIC-pn camera of the XMM-Newton space observatory for four consecutive time intervals. From the calculated shifts over the period from 2004 to 2018 of the X-ray intensity profiles along the northwestern rim of Vela Jr., limits were obtained on the angular expansion rate of the shock wave of this remnant’s region into a cloud of gas, probably hydrogen: minimum speed \(V_{\theta }^{{{\text{max}}}}\) = 0.29\('' \) ± 0.04\('' \) year^–1 and maximum \(V_{\theta }^{{60}}\) = 0.82\('' \) ± 0.11\('' \) year^–1. The hydrogen cloud with which the supernova shock wave interacts along the northwestern rim of Vela Jr. is very inhomogeneous. The upper limits for the age of the remnant and the distance to it based on the cloud density estimate are 1920 years and 450 pc, respectively. More stringent restrictions on such parameters of RX J0852.0–4622 as its age and distance to it were obtained by analyzing the remnant’s two-ring morphology based on its images in ultraviolet, X-ray, radio and gamma rays: 1190 ± 250 years and 280 ± 60 pc.