论文标题
Chandra无法检测到IA SN类型的X射线排放2018FHW/ASASSN-18TB
Chandra Fails to Detect X-ray Emission from Type Ia SN 2018fhw/ASASSN-18tb
论文作者
论文摘要
我们报告了Asassn-18TB/SN 2018FHW的Chandra X射线观测值，这是一种低光度IA型超新星，在其光谱中显示H线。在SN的位置未检测到X射线排放。根据假定的光谱模型，温度和柱密度，计算了最多3 $ \ times 10^{39} $ erg s $^{ - 1} $的光度的上限。这些与Chandra在Chandra观察到的两种IA-CSM SNE，SN 2005GJ和SN 2002IC进行了比较。上限低于IA-CSM SN型2012CA的X射线光度，这是X射线中唯一检测到的IA型SN。考虑到H $α$行的各种方案，表明在H $α$线检测时周围介质的密度可能高达10 $^8 $ cm $^{ - 3} $，但在x-ray观察时，一定已经降至5 $ \ times \，10^6 $ cm $^6 $ cm $^{ - 3} $。为了将IA SNE类型建立为X射线发射类别，必须在频谱中显示SNE的连续X射线观测值。
We report on Chandra X-ray observations of ASASSN-18tb/SN 2018fhw, a low luminosity Type Ia supernova that showed a H line in its optical spectrum. No X-ray emission was detected at the location of the SN. Upper limits to the luminosity of up to 3 $\times 10^{39}$ erg s$^{-1}$ are calculated, depending on the assumed spectral model, temperature and column density. These are compared to two Type Ia-CSM SNe, SN 2005gj and SN 2002ic, that have been observed with Chandra in the past. The upper limits are lower than the X-ray luminosity found for the Type Ia-CSM SN 2012ca, the only Type Ia SN to have been detected in X-rays. Consideration of various scenarios for the H$α$ line suggests that the density of the surrounding medium at the time of H$α$ line detection could have been as high as 10$^8$ cm$^{-3}$, but must have decreased below 5 $\times\, 10^6$ cm$^{-3}$ at the time of X-ray observation. Continual X-ray observations of SNe which show a H line in their spectrum are necessary in order to establish Type Ia SNe as an X-ray emitting class.
