论文标题
IIP Supernova类型的早期紫外线光谱和光学随访2021yja
Early-Time Ultraviolet Spectroscopy and Optical Follow-up Observations of the Type IIP Supernova 2021yja
论文作者
论文摘要
我们提出了三个时期的紫外线（UV）和光学HST/STIS光谱，附近的IIP Supernova型（SN）2021yja。我们将HST数据与Swift UVOT光谱的两个早期时期进行补充。 HST和Swift UVOT光谱与其他经过良好研究的IIP超新星（SNE）的光谱一致。紫外线光谱在早期表现出快速冷却，而光学中的变化较小。我们还提出舔/Kait光学光度法直至延迟尾阶段，与其他SNE IIP相比，高原和浅水下降非常长。我们使用TARDIS辐射转移代码对紫外线谱的建模非常适合高速爆炸，低的总灭绝$ E（B-V）= 0.07 $ mag和Mag Mag和sustolar cormalal金属性。我们没有发现来自其他加热源的紫外线（例如与Internelar培养基的相互作用，与观察到的平坦高原一致）没有显着贡献。此外，Mg II $λ$ 2798线的速度宽度与氢Balmer线的速度宽度相当，这表明紫外线发射仅限于靠近Photosphere的区域。
We present three epochs of early-time ultraviolet (UV) and optical HST/STIS spectroscopy of the young, nearby Type IIP supernova (SN) 2021yja. We complement the HST data with two earlier epochs of Swift UVOT spectroscopy. The HST and Swift UVOT spectra are consistent with those of other well-studied Type IIP supernovae (SNe). The UV spectra exhibit rapid cooling at early times, while less dramatic changes are seen in the optical. We also present Lick/KAIT optical photometry up to the late-time-tail phase, showing a very long plateau and shallow decline compared with other SNe IIP. Our modeling of the UV spectrum with the TARDIS radiative-transfer code produces a good fit for a high-velocity explosion, a low total extinction $E(B-V) = 0.07$ mag, and a subsolar metallicity. We do not find a significant contribution to the UV flux from an additional heating source, such as interaction with the circumstellar medium, consistent with the observed flat plateau. Furthermore, the velocity width of the Mg II $λ$2798 line is comparable to that of the hydrogen Balmer lines, suggesting that the UV emission is confined to a region close to the photosphere.
