2011/03/31 by Ping Zhou, Yang Chen
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Brightness #H II region #Line (geometry) #Maser #Molecular cloud #Solar mass #Spectroscopy #Supernova #Supernova remnant #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/743/1/4
12 pages (including 2 tables and 12 figures), to appear in ApJ
arxiv created 2011/10/08 · openalex publication_date 2011/11/17 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the molecular environment of the Galactic supernova remnant (SNR) Kesteven 78 and perform an XMM - Newton X-ray spectroscopic study for the northeastern edge of the remnant. SNR Kes 78 is found to interact with the molecular clouds (MCs) at a systemic local standard of rest velocity of 81 km s −1 . At around this velocity, the SNR appears to contact a long molecular strip in the northeast and a large cloud in the east as revealed in the 13 CO line, which may be responsible for the radio brightness peak and the OH maser, respectively. The 12 CO-line bright region morphologically matches the eastern bright radio shell in general, and the SNR is consistent in extent with a CO cavity. Broadened 12 CO-line profiles discerned in the eastern maser region and the western clumpy molecular arc and the elevated 12 CO ( J = 2–1)/( J = 1–0) ratios along the SNR boundary may be signatures of shock perturbation in the molecular gas. The SNR–MC association places the SNR at a kinematic distance of 4.8 kpc. The X-rays arising from the northeastern radio shell are emitted by underionized hot (∼1.5 keV), low-density (∼0.1 cm −3 ) plasma with solar abundance, and the plasma may be of intercloud origin. The age of the remnant is inferred to be about 6 kyr. The size of the molecular cavity in Kes 78 implies an initial mass around 22 M ☉ for the progenitor.