论文标题
用VLBI成像的Circinus Galaxy中的明亮超新星1996CR：具有复杂进化的壳结构
The Bright Supernova 1996cr in the Circinus Galaxy Imaged with VLBI: Shell Structure with Complex Evolution
论文作者
论文摘要
我们介绍了由Meerkat，ATCA和Alma制造的宽带无线电通量测量超新星（SN）1996CR，以及由澳大利亚长基线阵列的基线干扰法（VLBI）观察得出的图像。 SN 1996CR在2020年的光谱能量分布，年龄为$ t \ sim $ 8700 d，是一个幂律，具有通量密度，$ s \ propto vν{ - 0.588 \ pm 0.011} $在1和34 GHz之间，但可能以$> 35 $> 35 $ ghz陡峭。自$ t = 5370 $ d（2010）以来，该频谱已经变平。同样，由于$ t = 5370 $ d，通量密度迅速下降，$ s _ {\ rm 9 \，ghz} \ propto t^{ - 2.9} $。 $ t = 8859 $ d的VLBI图像显示了大致的圆形结构，中央最小让人联想到光学上微薄的球形壳的发射壳。 For a distance of 3.7 Mpc, the average outer radius of the radio emission at $t = 8859$ d was $(5.1 \pm 0.3) \times 10^{17}$ cm, and SN 1996cr has been expanding with a velocity of $4650 \pm 1060$ km s$^{-1}$ between $t=4307$ and 8859 d.在$ t = 4307 $ d之前，它必须经过大量减速。图像中与圆形外壳结构的偏差表明，一系列速度最高为$ \ sim $ 7000 km s $^{ - 1} $，并暗示存在环或赤道皮带状结构，而不是完整的球形壳。
We present broadband radio flux-density measurements supernova (SN) 1996cr, made with MeerKAT, ATCA and ALMA, and images made from very long baseline interferometry (VLBI) observations with the Australian Long Baseline Array. The spectral energy distribution of SN 1996cr in 2020, at age, $t \sim$8700 d, is a power-law, with flux density, $S \propto ν^{-0.588 \pm 0.011}$ between 1 and 34 GHz, but may steepen at $>35$ GHz. The spectrum has flattened since $t = 5370$ d (2010). Also since $t = 5370$ d, the flux density has declined rapidly, with $S_{\rm 9 \, GHz} \propto t^{-2.9}$. The VLBI image at $t = 8859$ d shows an approximately circular structure, with a central minimum reminiscent of an optically-thin spherical shell of emission. For a distance of 3.7 Mpc, the average outer radius of the radio emission at $t = 8859$ d was $(5.1 \pm 0.3) \times 10^{17}$ cm, and SN 1996cr has been expanding with a velocity of $4650 \pm 1060$ km s$^{-1}$ between $t=4307$ and 8859 d. It must have undergone considerable deceleration before $t = 4307$ d. Deviations from a circular shell structure in the image suggest a range of velocities up to $\sim$7000 km s$^{-1}$, and hint at the presence of a ring- or equatorial-belt-like structure rather than a complete spherical shell.
