Study of spectral index of giant radio galaxy from Leahy's Atlas: DA 240

Abstract

Here we investigate the giant radio galaxy DA 240, which is a FR II source. Specifically, we investigate its flux density, as well as the spectral index distribution. For that purpose, we used publicly available data for the source: Leahy's atlas of double radio-sources and NASA/IPAC Extragalactic Database (NED). We used observations at 326 MHz (92 cm) and at 608 MHz (49 cm) and obtained spectral index distributions between 326 and 608 MHz. For the first time we give spectral index map for these frequencies. We found that the synchrotron radiation is the dominant radiation mechanism over most of the area of DA 240, and also investigated the mechanism of radiation at some characteristic points, namely its core and the hotspots. The results of this study will be helpful for understanding the evolutionary process of the DA 240 radio source.Comment: 9 pages, 5 figures. Accepted for publication in Contrib. Astron. Obs. Skalnate Pleso (Invited lecture at V Meeting on Astrophysical Spectroscopy - A&M DATA 2023