论文标题
与Muse一起研究NGC 7793中的ISM。
Studying the ISM at ~10 pc scale in NGC 7793 with MUSE -- I. Data description and properties of the ionised gas
论文作者
论文摘要
使用Muse AO数据，我们以$ \ sim $ 10 pc的空间分辨率探测当地螺旋星系NGC 7793中的ISM。我们确定HII区域并编译超新星残留物（SNR），行星星云（PNE）和Wolf Rayet Star（WR）的目录。我们计算[SII] 6716/6731和[SIII] 6312/9069线比的电子密度和温度。我们通过BPT图与气体速度分散相结合的电离气体的性质研究。我们从光谱上确认2个先前检测到的WR星和一个SNR，并报告发现7 WR，1 SNR和2个PNE的发现。根据定义HII区域边界的方法，扩散的离子气体（DIG）分数为$ \ sim $ 27和42％。与先前的研究一致，我们发现DIG表现出增强的[SII]/H $α$和[NII]/H $α$比率，中位温度的中位温度为$ \ sim $ 3000 k $ 3000 K。我们还观察到温度与H $α$表面亮度之间的明显反相关性。总体而言，观察到的[SII] 6716/6731比率在1 $σ$之内与$ n_e $ <30 cm $^{ - 3} $保持一致，而DIG和HII区域的分布几乎相同。离子气体的速度分散体表明，挖掘的湍流程度高于HII区域。与光电子化和冲击模型的比较表明，弥散成分只能通过冲击来部分解释，并且它很可能与从密度有界的HII区域泄漏的光子或演变的田间恒星的辐射相一致。 [简略]
Using MUSE AO data, we probe the ISM in the local spiral galaxy NGC 7793 at a spatial resolution of $\sim$ 10 pc. We identify HII regions and compile a catalogue of supernova remnants (SNRs), planetary nebulae (PNe) and Wolf Rayet stars (WR). We compute electron densities and temperatures from the [SII]6716/6731 and [SIII]6312/9069 line ratios. We study the properties of the ionised gas through BPT diagrams combined with gas velocity dispersion. We spectroscopically confirm 2 previously detected WR stars and a SNR and report the discovery of 7 WR, 1 SNR, and 2 PNe. The diffuse ionized gas (DIG) fraction is between $\sim$ 27 and 42% depending on the method used to define the HII region boundaries. In agreement with previous studies, we find that the DIG exhibits enhanced [SII]/H$α$ and [NII]/H$α$ ratios and a median temperature that is $\sim$ 3000 K higher than in HII regions. We also observe an apparent inverse correlation between temperature and H$α$ surface brightness. Overall, the observed [SII]6716/6731 ratio is consistent within 1$σ$ with $n_e$ < 30 cm$^{-3}$, with an almost identical distribution for the DIG and HII regions. The velocity dispersion of the ionised gas indicates that the DIG has a higher degree of turbulence than the HII regions. Comparison with photoionisation and shock models reveals that the diffuse component can only partially be explained via shocks and that it is most likely consistent with photons leaking from density bounded HII regions or with radiation from evolved field stars. [abridged]
