论文标题
重新访问SNR G57.2+0.8的距离，环境和超新星属性，该特性托有SGR 1935+2154
Revisiting the distance, environment and supernova properties of SNR G57.2+0.8 that hosts SGR 1935+2154
论文作者
论文摘要
我们已经对超新星残留（SNR）G57.2+0.8及其环境进行了多波长研究。 SNR主持了Magnetar SGR 1935+2154，该SGR在2020年4月28日发出了非常明亮的MS-DURATION无线电爆发（Chime/FRB Collaboration等，2020; Bochenek etal。2020）。我们使用了来自银河系图像滚动绘画（MWISP）CO线调查的12CO和13CO J = 1-0数据来搜索与G57.2+0.8相关的分子气体，以限制SNR及其磁性的物理参数（例如，距离）。我们报告说，SNR G57.2+0.8可能会在局部静止标准（LSR）速度V_ {LSR} 〜30 km/s上影响分子云（MCS），并激发弱的1720 MHz OH Maser，峰值通量密度为47 MJY/BEAM。落入SNR的随机OH点的机会巧合<12％，OH-CO通信机会在Maser Spot中为7％。这结合起来给出了OH Maser的<1％错误概率，表明实际的Maser检测。 MCS的LSR速度将SNR和磁铁放置在d = 6.6 +/- 0.7 kpc的运动学距离处。 SNR的热X射线发射和相对密集的环境的非探测表明，G57.2+0.8是一个演变的SNR，年龄$ t> 1.6 \ times 10^4 $（d/6.6 kpc）yr。 G57.2+0.8的爆炸能量低于$ 2 \ times 10^{51}（N_0/10 cm^{ - 3}）^{1.16}（d/〜6.6 kpc）^{3.16} $ erg，即使假设高气流$ n_0 $ $ n_0 $ = 10 cm = 10 cm = 10 cm = 10 cm = 10 cm = 10 cm = 10 cm = 10 cm。这加强了这样一种观点，即磁铁不一定是由于非常有活力的超新星爆炸而引起的。
We have performed a multi-wavelength study of supernova remnant (SNR) G57.2+0.8 and its environment. The SNR hosts the magnetar SGR 1935+2154, which emitted an extremely bright ms-duration radio burst on 2020 Apr 28 (The Chime/Frb Collaboration et al. 2020; Bochenek et al. 2020). We used the 12CO and 13CO J=1-0 data from the Milky Way Image Scroll Painting (MWISP) CO line survey to search for molecular gas associated with G57.2+0.8, in order to constrain the physical parameters (e.g., the distance) of the SNR and its magnetar. We report that SNR G57.2+0.8 is likely impacting the molecular clouds (MCs) at the local standard of rest (LSR) velocity V_{LSR} ~ 30 km/s and excites a weak 1720 MHz OH maser with a peak flux density of 47 mJy/beam. The chance coincidence of a random OH spot falling in the SNR is <12%, and the OH-CO correspondence chance is 7% at the maser spot. This combines to give < 1% false probability of the OH maser, suggesting a real maser detection. The LSR velocity of the MCs places the SNR and magnetar at a kinematic distance of d=6.6 +/- 0.7 kpc. The nondetection of thermal X-ray emission from the SNR and the relatively dense environment suggests G57.2+0.8 be an evolved SNR with an age $t>1.6 \times 10^4$ (d/6.6 kpc) yr. The explosion energy of G57.2+0.8 is lower than $2 \times 10^{51}(n_0/10 cm^{-3})^{1.16} (d/~6.6 kpc)^{3.16}$ erg, which is not very energetic even assuming a high ambient density $n_0$ = 10 cm$^{-3}$. This reinforces the opinion that magnetars do not necessarily result from very energetic supernova explosions.
