The Physics of the Coronal-line Region for Galaxies in Mapping Galaxies at Apache Point Observatory
The Physics of the Coronal-line Region for Galaxies in Mapping Galaxies at Apache Point Observatory
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DOI：
10.3847/1538-4357/ac1343
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
J. Negus;J. Comerford;Francisco Müller Sánchez;J. Barrera-Ballesteros;N. Drory;S. Rembold;R. Riffel
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文献类型：
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作者：
J. Negus;J. Comerford;Francisco Müller Sánchez;J. Barrera-Ballesteros;N. Drory;S. Rembold;R. Riffel
日冕线区域(CLR)可能是活动星系核(AGN)活动的重要示踪物，但其基本性质和范围仍未得到解决。以前的研究表明，CLR是由活动星系核驱动的外流产生的，它位于宽线区和窄线区之间的一个不同的区域，这使得它距离银河系中心几十到数百秒。在这里，我们研究了斯隆数字巡天IV阿帕奇点天文台(MANGA)星表中发射的10个冕线(CL；电离势≳100 eV)星系，其中一个或多个CLS在连续统上方的≥5σ探测到，至少有10个空间--这是最大的此类漫画星表。我们发现CLR的范围要大得多，从银河系中心延伸到1.3-23kpc。我们将我们的10个CL星系样本与现有最大的漫画AGN星表进行交叉匹配，并确定其中7个；其余3个星系中有两个是星系合并，最后一个是AGN候选星系。此外，我们测量的CLR电子平均温度在12,331到22,530 K之间，略高于纯活动星系核光电离的典型阈值(∼20,000 K)，并表明CLR中的冲击(例如，合并引起的或来自超新星残骸的)。我们的理由是，由中心连续谱源发射的电离光子(即活动星系核的光电离)主要产生CLS，而高能冲击是一种额外的电离机制，可能产生我们测量的最大范围的CLR。
The fundamental nature and extent of the coronal-line region (CLR), which may serve as a vital tracer for active galactic nucleus (AGN) activity, remain unresolved. Previous studies suggest that the CLR is produced by AGN-driven outflows and occupies a distinct region between the broad-line region and the narrow-line region, which places it tens to hundreds of parsecs from the galactic center. Here, we investigate 10 coronal line (CL; ionization potential ≳100 eV) emitting galaxies from the Sloan Digital Sky Survey IV Mapping Galaxies at Apache Point Observatory (MaNGA) catalog with emission from one or more CLs detected at ≥5σ above the continuum in at least 10 spaxels—the largest such MaNGA catalog. We find that the CLR is far more extended, reaching out to 1.3–23 kpc from the galactic center. We crossmatch our sample of 10 CL galaxies with the largest existing MaNGA AGN catalog and identify seven in it; two of the remaining three are galaxy mergers and the final one is an AGN candidate. Further, we measure the average CLR electron temperatures as ranging between 12,331 and 22,530 K, slightly above the typical threshold for pure AGN photoionization (∼20,000 K) and indicative of shocks (e.g., merger induced or from supernova remnants) in the CLR. We reason that ionizing photons emitted by the central continuum source (i.e., AGN photoionization) primarily generate the CLs, and that energetic shocks are an additional ionization mechanism that likely produce the most extended CLRs we measure.