论文标题
速度颠簸：SN 2021AEFX表明，单独的多普勒移位可以解释某种类型的IA超新星的早期蓝色通量
A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone can Explain Early-Excess Blue Flux in Some Type Ia Supernovae
论文作者
论文摘要
我们提出了IA型超新星（SN IA）2021AEFX的早期光度法和光谱观测。与正常的SNE IA相比，早期的U波段光线曲线显示出多余的通量。我们建议，早期的蓝色通量可能是由于爆炸后最初几天的光谱速度迅速变化，这是由于几天的时间尺度上从U到B带的Ca II H＆K特征发射而产生的。对于所有具有广泛吸收特征和超过25,000 km/s的早期速度的SNE IA可能会占主导地位。它可能是Sne IA早期u-band通量的主要原因之一，该sne IA具有早期高速度。这种效果在UV过滤器以及SN光谱分布迅速上升至更长波长的地方也可能占主导地位。速度的快速变化只能在U波段中产生单调变化（磁通空间）。对于在较低速度爆炸并在早期发射中具有更结构化形状的物体，还必须有一个额外的参数产生早期多样性。需要更多的早期观察，特别是早期光谱，以确定这种影响在SNE IA内的突出程度。
We present early-time photometric and spectroscopic observations of the Type Ia Supernova (SN Ia) 2021aefx. The early time u-band light curve shows an excess flux when compared to normal SNe Ia. We suggest that the early-excess blue flux may be due to a rapid change in spectral velocity in the first few days post explosion, produced by the emission of the Ca II H&K feature passing from the u to the B bands on the time scale of a few days. This effect could be dominant for all SNe Ia which have broad absorption features and early-time velocities over 25,000 km/s. It is likely to be one of the main causes of early-excess u-band flux in SNe Ia which have early-time high-velocities. This effect may also be dominant in the UV filters, as well as in places where the SN spectral energy distribution is quickly rising to longer wavelengths. The rapid change in velocity can only produce a monotonic change (in flux-space) in the u-band. For objects which explode at lower velocities, and have a more structured shape in the early-excess emission, there must also be an additional parameter producing the early-time diversity. More early time observations, in particular early spectra, are required to determine how prominent this effect is within SNe Ia.
