论文标题
SN 2020JGB：由星形银河系中的氦壳爆炸触发的特殊IA型超新星
SN 2020jgb: A Peculiar Type Ia Supernova Triggered by a Helium-Shell Detonation in a Star-Forming Galaxy
论文作者
论文摘要
在A $ \ sim $$ 1 \，\ sim $$ 1 \，\ mathrm {m_ \ odot} $ speare and Magine and Supere and Supere and Supere and Super-Speare（s ia s ia s ia s ia s ia s ia s ia s ia ia s ia s ia s ia ia，大规模的WD可以解释一些最近观察到的奇特SNE IA。我们提出了SN 2020JGB的观察，这是Zwicky瞬态设施（ZTF）发现的奇特的SN IA。 Near maximum light, SN 2020jgb is slightly subluminous (ZTF $g$-band absolute magnitude $M_g$ between $-18.2$ and $-18.7$ mag depending on the amount of host galaxy extinction) and shows an unusually red color ($g_\mathrm{ZTF}-r_\mathrm{ZTF}$ between 0.4 and 0.2 mag) due to strong $ \ sim $ 5000 $Å$的蓝色蓝色。这些属性类似于SN 2018Byg的属性，这是一种与较厚的HE壳双重爆炸（DDET）SN相一致的奇特SN IA。使用详细的辐射转移模型，我们表明SN 2020JGB的光谱和光度演变与$ \ sim $$ 0.95 \，\ mathrm {m_ \ odot} $（c/o core + heell; to $ \ sim $ \ sim $ \ sim $ ____________________祖细胞被厚的（$ \ sim $$ 0.13 \，\ mathrm {m_ \ odot} $）点燃。我们在SN 2020JGB的近红外（NIR）光谱中检测到$ \ sim $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ \ sim，它可以检测到一个突出的吸收功能，该功能可能来自最外面的弹射器中的无燃烧的氦气。虽然样本量有限，但在所有厚实的HE-Shell DDET候选候选物中都检测到了相似的1 $μ\ MATHRM {M} $，迄今为止获得的NIR光谱。 SN 2020JGB也是第一个在恒星形成的星系中发现的升级，厚的Heshell DDET SN，毫无疑问地表明，Heshell DDET物体在恒星形成和被动星系中都出现，与正常的SN IA群体一致。
The detonation of a thin ($\lesssim$$0.03\,\mathrm{M_\odot}$) helium shell (He-shell) atop a $\sim$$1\,\mathrm{M_\odot}$ white dwarf (WD) is a promising mechanism to explain normal Type Ia supernovae (SNe Ia), while thicker He-shells and less massive WDs may explain some recently observed peculiar SNe Ia. We present observations of SN 2020jgb, a peculiar SN Ia discovered by the Zwicky Transient Facility (ZTF). Near maximum light, SN 2020jgb is slightly subluminous (ZTF $g$-band absolute magnitude $M_g$ between $-18.2$ and $-18.7$ mag depending on the amount of host galaxy extinction) and shows an unusually red color ($g_\mathrm{ZTF}-r_\mathrm{ZTF}$ between 0.4 and 0.2 mag) due to strong line-blanketing blueward of $\sim$5000 $Å$. These properties resemble those of SN 2018byg, a peculiar SN Ia consistent with a thick He-shell double detonation (DDet) SN. Using detailed radiative transfer models, we show that the optical spectroscopic and photometric evolution of SN 2020jgb are broadly consistent with a $\sim$$0.95\,\mathrm{M_\odot}$ (C/O core + He-shell; up to $\sim$$1.00\,\mathrm{M_\odot}$ depending on the total host extinction) progenitor ignited by a thick ($\sim$$0.13\,\mathrm{M_\odot}$) He-shell. We detect a prominent absorption feature at $\sim$1 $μ\mathrm{m}$ in the near-infrared (NIR) spectrum of SN 2020jgb, which could originate from unburnt helium in the outermost ejecta. While the sample size is limited, similar 1 $μ\mathrm{m}$ features have been detected in all the thick He-shell DDet candidates with NIR spectra obtained to date. SN 2020jgb is also the first subluminous, thick He-shell DDet SN discovered in a star-forming galaxy, indisputably showing that He-shell DDet objects occur in both star-forming and passive galaxies, consistent with the normal SN Ia population.
