Discovery of molecular and atomic clouds associated with the gamma-ray supernova remnant Kesteven 79
astro-ph.GA
/ Authors
M. Kuriki, H. Sano, N. Kuno, M. Seta, Y. Yamane, T. Inaba, T. Nagaya, S. Yoshiike, K. Okawa, D. Tsutsumi
and 14 more authors
Y. Hattori, M. Kohno, S. Fujita, A. Nishimura, A. Ohama, M. Matsuo, Y. Tsuda, K. Torii, T. Minamidani, T. Umemoto, G. Rowell, A. Bamba, K. Tachihara, Y. Fukui
/ Abstract
We carried out $^{12}$CO($J$ = 1-0) observations of the Galactic gamma-ray supernova remnant (SNR) Kesteven 79 using the Nobeyama Radio Observatory 45 m radio telescope, which has an angular resolution of $\sim20$ arcsec. We identified molecular and atomic gas interacting with Kesteven 79 whose radial velocity is $\sim80$ km s$^{-1}$. The interacting molecular and atomic gases show good spatial correspondence with the X-ray and radio shells, which have an expanding motion with an expanding velocity of $\sim4$ km s$^{-1}$. The molecular gas associated with the radio and X-ray peaks also exhibits a high-intensity ratio of CO 3-2/1-0 $>$ 0.8, suggesting a kinematic temperature of $\sim24$ K, owing to heating by the supernova shock. We determined the kinematic distance to the SNR to be $\sim5.5$ kpc and the radius of the SNR to be $\sim8$ pc. The average interstellar proton density inside of the SNR is $\sim360$ cm$^{-3}$, of which atomic protons comprise only $\sim10$ $\%$. Assuming a hadronic origin for the gamma-ray emission, the total cosmic-ray proton energy above 1 GeV is estimated to be $\sim5 \times 10^{48}$ erg.