科研之友
微信
新浪微博
Facebook
分享链接
摘要
We report our independent Gey gamma-ray study the young shell-type supernova remnant (SNR) Kes 73, which harbors a central magnetar, and CO-line millimeter observations toward the SNR. Using 7.6 years of Fermi-LAT observation data, we detected an extended gamma-ray source ("source A") with centroid on the west of the SNR, with a significance of 21 sigma in 0.1-300 GeV and an error circle of 5'.4n angular radius. The gamma-ray spectrum cannot be reproduced by a pure leptonic emission or a pure emission from the magnetar, and thus a hadronic emission component is needed. The CO-line observations reveal a molecular cloud (MC) at V-LSR similar to 90 km s(-1), which demonstrates morphological correspondence with the western boundary of the SNR brightened in multiwavelength. The (CO)-C-12 (J-1)/(CO)-C-12 (J-1-0)retioin the left (blue) wing 85-88 km s(-1) is prominently elevated to similar to 1.1 along the northwestern boundary, providing kinematic evidence of the SNR-MC interaction. This SNR-MC association yields a kinematic distance 9 kpc to Kes 73. The MC is shown to be capable of accounting for the hadronic gamma ray emission component. The gamma-ray spectrum can be interpreted with a pure hadronic emission or a magnetar+ hadronic hybrid emission. In the case of pure hadronic emission, the spectral index of the protons is 2.4, very similar to that of the radio-emitting electrons, essentially consistent with the diffusive shock acceleration theory. In the case of magnetar+ hadronic hybrid emission, a magnetic field decay rate. 1036 erg s(-1) is needed to power the magnetar's curvature radiation.
- 出版日期2017-12-10
- 单位北京师范大学; 南京大学; 中国科学院紫金山天文台
