1. CO Observations of the Type Ia Supernova Remnant 3C 397 by the Nobeyama 45-m Radio Telescope: Possible Evidence for the Single-Degenerated Explosion
- Author
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Ito, Daisuke, Sano, Hidetoshi, Nakazawa, Kazuhiro, Mitsuishi, Ikuyuki, Fukui, Yasuo, Sudou, Hiroshi, and Takaba, Hiroshi
- Subjects
Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Astrophysics of Galaxies - Abstract
We present a new CO observation toward the Type Ia supernova remnant (SNR) 3C 397 using the Nobeyama 45-m radio telescope at an unprecedent angular resolution of $\sim$18''. We newly found that the CO cloud at $V_{\mathrm{LSR}}$ = 55.7-62.2 km s$^{-1}$ (60 km s$^{-1}$ cloud) shows a good spatial correspondence with the radio continuum shell. We also found an expanding gas motion of the 60 km s$^{-1}$ cloud with an expansion velocity of $\sim$3 km s$^{-1}$, which is thought to be formed by the pre-and/or post-supernova feedback. By considering the positions of Galactic spiral arms and the X-ray/HI absorption studies, we concluded that 3C 397 is physically associated with the 60 km s$^{-1}$ cloud rather than the previously known CO cloud at $V_{\mathrm{LSR}}$ $\sim$30 km s$^{-1}$. Given that the previously measured pre-shock density is $\sim$2-5 cm$^{-3}$, the expanding motion of the 60 km s$^{-1}$ cloud was likely formed by the pre-supernova feedback known as optically thick wind. The scenario is consistent with that 3C 397 exploded inside a wind-blown bubble as a single degenerate system., Comment: 11 pages, 9 figures, submitted to The Astrophysical Journal (ApJ)
- Published
- 2024