论文标题
如[Fe II] 1.644 $μ$ m，HST中观察到的NGC6946的超新星残留人口
The Supernova Remnant Population of NGC6946 as Observed in [Fe II] 1.644 $μ$m with HST
论文作者
论文摘要
NGC6946是一个高恒星的面对面螺旋星系，自1917年以来一直拥有十个超新星。毫不奇怪，已经将大量的超新星残留物和候选人确定为具有高[s II]的光学星云[s ii]：H $α$线率（147）或Compact Actact非无线电（35）。但是，这两个样本之间只有七个重叠。在这里，我们将[Fe II] 1.644 $μ$ M排放量作为新的诊断，以搜索超新星残余物以解决这种差异。 [Fe II]预计在超新星残留物的辐射冲击中将相对强，而在HII地区几乎没有。与通常用于识别残留物的光学线相比，它不太容易受到视线的吸收影响。使用HST上的WFC3摄像头的数据}，我们在NGC6946中识别132 [Fe II]发射星云，可能是超新星残留物。其中，有54位与先前已知的光学超新星残留物保持一致。其余的78个物体是新的；在H $α$和[S II]中的新HST图像中，这44个可见。这将NGC6946中的超新星残留候选者（从光学和/或IR数据）带到225中。在此扩展的列表中发现了14个与无线电超级Nova残留候选者（在我们的搜索区域中的30个）共同巧合。识别如此多的新残留候选人验证了[Fe II]图像查找残留物的使用，并建议其他星系中的残留搜索可能远非完整。
NGC6946 is a high star formation rate face-on spiral galaxy that has hosted ten supernovae since 1917. Not surprisingly, a large number of supernova remnants and candidates have been identified either as optical nebulae with high [S II]:H$α$ line ratios (147) or as compact non-thermal radio sources (35). However, there are only seven overlaps between these two samples. Here, we apply [Fe II] 1.644 $μ$m emission as a new diagnostic to search for supernova remnants in an attempt to resolve this discrepancy. [Fe II] is expected to be relatively strong in the radiative shocks of supernova remnants and almost absent in HII regions. It is less susceptible to the effects of absorption along the line of sight than the optical lines normally used to identify remnants. Using data from the WFC3 camera on HST}, we identify 132 [Fe II] emission nebulae in NGC6946 as likely supernova remnants. Of these, 54 align with previously known optical supernova remnants. The remaining 78 objects are new; of these 44 are visible in new HST imagery in H$α$ and [S II]. This brings the total number of supernova remnant candidates (from optical and/or IR data) in NGC6946 to 225. A total of 14 coincidences with radio supernova remnant candidates (out of 30 in our search area) are found in this expanded list. The identification of so many new remnant candidates validates the use of [Fe II] imagery for finding remnants, and suggests that previous remnant searches in other galaxies may be far from complete.
