论文标题
强钙排放表明紫外线施加的IA SN 2019YVQ是亚chandrasekhar质量爆炸的结果
Strong Calcium Emission Indicates that the Ultraviolet-Flashing Type Ia SN 2019yvq was the Result of a Sub-Chandrasekhar Mass Double-Detonation Explosion
论文作者
论文摘要
我们提出了IA型超新星（SN IA）SN 2019YVQ的静脉光谱，该爆炸后具有明亮的蓝色和紫外线闪光，随后类似于其他SNE IA。尽管SN 2019YVQ显示了其他几个罕见特征，例如峰值亮度接近峰值的持续高喷射速度，但它并不是特别奇特，如果未观察到早期的“过量”发射，则可能包括在宇宙样品中。多余的通量可以通过与祖细胞系统和爆炸机制的细节相关的几种不同的物理模型来解释。每个都对后期的光学薄发射有独特的预测。在我们的Nebular光谱中，我们检测到强[Ca II] $λλ$ 7291，7324和Ca Nir三胞胎发射，这与双重爆炸一致。我们没有检测到H，He或[O I]发射，这是对某些单一分类祖细胞系统和暴力白矮人合并的预测。扫描h或他的量分别<2.8 x 10^-4和2.4 x 10^-4 msun。除了强大的CA发射外，SN 2019YVQ nebular Spectrum与具有相同光曲线形状的典型SNE IA相似。与双十字模型相比，我们发现CA发射与总祖细胞质量为1.15 MSUN的模型一致。但是，我们注意到，较低的祖细胞质量可以更好地解释早期的光曲线和峰值光度。 SN 2019YVQ的唯一属性表明，厚的He-shell双重测量仅为$ 1.1^{+2.1} _ { - 1.1} \％$的总“正常” SN IA IA速率。 SN 2019YVQ是最好的例子之一，即似乎需要多个祖先通道来重现“正常” SNE IA的全部多样性所必需的。
We present nebular spectra of the Type Ia supernova (SN Ia) SN 2019yvq, which had a bright flash of blue and ultraviolet light after exploding, followed by a rise similar to other SNe Ia. Although SN 2019yvq displayed several other rare characteristics such as persistent high ejecta velocity near peak brightness, it was not especially peculiar and if the early "excess" emission were not observed, it would likely be included in cosmological samples. The excess flux can be explained by several different physical models linked to the details of the progenitor system and explosion mechanism. Each has unique predictions for the optically thin emission at late times. In our nebular spectra, we detect strong [Ca II] $λλ$7291, 7324 and Ca NIR triplet emission, consistent with a double-detonation explosion. We do not detect H, He, or [O I] emission, predictions for some single-degenerate progenitor systems and violent white dwarf mergers. The amount of swept-up H or He is <2.8 x 10^-4 and 2.4 x 10^-4 Msun, respectively. Aside from strong Ca emission, the SN 2019yvq nebular spectrum is similar to those of typical SNe Ia with the same light-curve shape. Comparing to double-detonation models, we find that the Ca emission is consistent with a model with a total progenitor mass of 1.15 Msun. However, we note that a lower progenitor mass better explains the early light-curve and peak luminosity. The unique properties of SN 2019yvq suggest that thick He-shell double-detonations only account for $1.1^{+2.1}_{-1.1}\%$ of the total "normal" SN Ia rate. SN 2019yvq is one of the best examples yet that multiple progenitor channels appear necessary to reproduce the full diversity of "normal" SNe Ia.
