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, D., Sano, H., Nakazawa, K., Mitsuishi, I., Fukui, Y., Sudou, H., and Takaba, H.
- Subjects
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TYPE I supernovae , *SUPERNOVA remnants , *RADIO telescopes , *INTERSTELLAR medium , *VELOCITY - Abstract
We present a new CO observation toward the Type Ia supernova remnant 3C 397 using the Nobeyama 45 m radio telescope at an unprecedented angular resolution of ∼18″. We newly found that the CO cloud at V 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 ∼3 km s−1, which is thought to be formed by the pre- and/or postsupernova feedback. By considering the positions of Galactic spiral arms and the X-ray/H i 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 LSR ∼ 30 km s−1. Given that the previously measured preshock density is ∼2–5 cm−3, the expanding motion of the 60 km s−1 cloud was likely formed by the presupernova feedback known as optically thick wind. The scenario is consistent with the fact that 3C 397 exploded inside a wind-blown bubble as a single degenerate system. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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