A look at the high energy aspects of the supernova remnant G309.8+00.0 with eROSITA and Fermi-LAT

• Published in: arXiv.org
• Main Authors: Michailidis, Miltiadis, Pühlhofer, Gerd, Santangelo, Andrea, Sasaki, Manami, Becker, Werner
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 25.06.2024
• Subjects: Absorption; Density; Emission; Energy bands; Gamma ray astronomy; Gamma ray sources; Physics - High Energy Astrophysical Phenomena; Sky surveys (astronomy); Soft x rays; Spectrum analysis; Supernova remnants; X-ray astronomy; X-rays
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2406.17493

Supernova remnant (SNR) detection along the Galactic plane poses a number of challenges. The SNR G309.8+00.0 lies exactly on the Galactic plane, with its center coinciding with galactic latitude (b)=0 deg. In this paper we report the first detection of the SNR G309.8+00.0 in X-rays and \(\gamma\) rays, using stacked data from the first four consecutive extended ROentgen Survey Imaging Telescope Array (eROSITA) -- on board the Russian-German Spektrum Roentgen Gamma (SRG) -- all-sky surveys (eRASS:4) and \(\sim15.5\) yr of Pass 8 data recorded from Fermi-LAT, respectively. The SNR appears to have an elliptical shape of 0.43 x 0.32 deg in size in both radio synchrotron and X-ray data. The SNR's emission exhibits a shell-like morphology and good spatial correlation in both energy bands. The X-ray emission was solely detected in the 1-2 keV energy band (subject to strong absorption at soft X-rays) and the spectral analysis results of eRASS:4 data present a purely thermal SNR with a high absorption column density \(3.1_{-0.5}^{+0.7}\cdot10^{22}~\mathrm{cm^{-2}}\) and a temperature of \(0.34\pm0.1\) keV. In combination with optical extinction data, the absorption column density values derived from the remnant's spectral analysis support a remnant's distance greater than 6 kpc, rather than a 3.12 kpc distance as reported in the literature, and yield an age of \(1-3.5\cdot10^5\) yr. Employing \(\sim15.5\) yr of Fermi-LAT \(\gamma\)-ray data at and around the remnant's vicinity, we confirm the detection of the to-date unidentified 4FGL J1349.5-6206c source that can either be modeled as a single source or a conglomerate of multiple distinct source components and we argue that the SNR G309.8+00.0 likely represents at least a significant portion (if not all) of the emission from the 4FGL J1349.5-6206c \(\gamma\)-ray source.