A Detailed Study of the Interstellar Protons toward the TeV gamma-Ray SNR RX J0852.0-4622 (G266.2-1.2, Vela Jr.): The Third Case of the gamma-Ray and ISM Spatial Correspondence

作者：Fukui Y^*; Sano H^*; Sato J; Okamoto R; Fukuda T; Yoshiike S; Hayashi K; Torii K; Hayakawa T; Rowell G; Filipovic M D; Maxted N; McClure Griffiths N M; Kawamura A; Yamamoto H; Okuda T; Mizuno N; Tachihara K; Onishi T; Mizuno A; Ogawa H

来源：Astrophysical Journal, 2017, 850(1): 71.

DOI：10.3847/1538-4357/aa9219

• cosmic rays
• gamma rays: ISM
• ISM: clouds
• ISM: individual objects (RX J0852.0-4622)
• ISM: supernova remnants

We present a new analysis of the interstellar protons toward the TeV gamma-ray SNR RX J0852.0-4622 (G266.2-1.2, Vela Jr.). We used the NANTEN2 (CO)-C-12(J = 1-0) and Australia Telescope Compact Array and Parkes H I data sets in order to derive the molecular and atomic gas associated with the TeV gamma-ray shell of the SNR. We find that atomic gas over a velocity range from V-LSR =-4 to 50 km s(-1) or 60 km s(-1) is associated with the entire SNR, while molecular gas is associated with a limited portion of the SNR. The large velocity dispersion of the H I is ascribed to the expanding motion of a few H I shells overlapping toward the SNR but is not due to the Galactic rotation. The total masses of the associated H I and molecular gases are estimated to be similar to 2.5 x 10(4) M-circle dot and similar to 10(3) M-circle dot), respectively. A comparison with the High Energy Stereoscopic System TeV gamma-rays indicates that the interstellar protons have an average density around 100 cm(-3) and shows a good spatial correspondence with the TeV gamma-rays. The total cosmic-ray proton energy is estimated to be 1048 erg for the hadronic gamma-ray production, which may still be an underestimate by a factor of a few due to a small filling factor of the SNR volume by the interstellar protons. This result presents a third case, after RX J1713.7-3946 and HESS J1731-347, of the good spatial correspondence between the TeV gamma-rays and the interstellar protons, lending further support for a hadronic component in the gamma-rays from young TeV gamma-ray SNRs.

• 出版日期2017-11-20
• 单位中国科学院国家天文台