论文标题
低亮度型IAX Supernova 2019GSC的观察：SN 2008HA的淡淡克隆？
Observations of the low-luminosity Type Iax supernova 2019gsc: a fainter clone of SN 2008ha?
论文作者
论文摘要
我们介绍了微弱和快速发展型IAX SN 2019GSC的光学光度和光谱观测，从G波段最大的时间延伸到最大值后大约五十天，当物体褪色到明显的R波段幅度M_R = 22.48 +/- 0.11 mag。 SN 2019GSC达到的峰值发光度仅为m_g = -13.58 +/- 0.15 mag，并以最大下降速率delta（M_15）_g = 1.08 +/- 0.14 mag进行表征。这些光曲线参数可与SN 2008HA的M_G = -13.89 +/- 0.14 mag在峰值和delta（M_15）_g = 1.80 +/- 0.03 mag相当。 SN 2019GSC的频谱特征也类似于SN 2008HA在类似阶段的光谱特征。这既包括最大的极低的弹射速度，约3,000 km/s，并且在较晚（相+54 d）时（+54 d）强的禁止铁和钴线，以及禁止和允许的钙特征。此外，类似于SN 2008HA的类似，SN 2019GSC的Bologemetric Light曲线与0.003 +/- 0.001 MSOL镍的产生一致。爆炸参数，m_ej = 0.13 msol和e_k = 12 x 10e48 erg，也与SN 2008HA推断的爆炸参数也相似。我们估计SN 2019GSC的宿主星系的亚晶氧丰度（12 + log10（o/h）= 8.10 +/- 0.18 DEX），与SN 2008HA的同样金属贫困环境一致。总的来说，我们的SN 2019GSC数据集表明，这是包括SN 2008HA和SN 2010AE在内的小型但不断增长的Extreme SN IAX的成员。
We present optical photometric and spectroscopic observations of the faint-and-fast evolving type Iax SN 2019gsc, extending from the time of g-band maximum until about fifty days post maximum, when the object faded to an apparent r-band magnitude m_r = 22.48+/-0.11 mag. SN 2019gsc reached a peak luminosity of only M_g = -13.58 +/- 0.15 mag, and is characterised with a post-maximum decline rate Delta(m_15)_g = 1.08 +/- 0.14 mag. These light curve parameters are comparable to those measured for SN 2008ha of M_g = -13.89 +/- 0.14 mag at peak and Delta(m_15)_g = 1.80 +/- 0.03 mag. The spectral features of SN 2019gsc also resemble those of SN 2008ha at similar phases. This includes both the extremely low ejecta velocity at maximum, about 3,000 km/s, and at late-time (phase +54 d) strong forbidden iron and cobalt lines as well as both forbidden and permitted calcium features. Furthermore, akin to SN 2008ha, the bolometric light curve of SN 2019gsc is consistent with the production of 0.003 +/- 0.001 Msol of nickel. The explosion parameters, M_ej = 0.13 Msol and E_k = 12 x 10E48 erg, are also similar to those inferred for SN 2008ha. We estimate a sub-solar oxygen abundance for the host galaxy of SN 2019gsc, (12 + log10(O/H) = 8.10 +/- 0.18 dex), consistent with the equally metal-poor environment of SN 2008ha. Altogether, our dataset of SN 2019gsc indicates that this is a member of a small but growing group of extreme SN Iax that includes SN 2008ha and SN 2010ae.
