日冕气体激发作为超大质量黑洞质量的示踪物：关于中红外日冕[Ne v]谱线
Coronal gas excitation as a tracer of supermassive black hole mass: on the mid-IR coronal [Ne v] lines
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中文总结 AI 辅助
本研究通过分析27个SMBH质量跨度达三个数量级的AGN的斯皮策光谱，发现[Ne v]线与SMBH质量存在强相关性，证实日冕线可作为SMBH质量的可靠替代指标。
中文摘要 AI 辅助
日冕线（CL）或许是活动星系核（AGN）中超大质量黑洞（SMBH）质量的可靠替代指标，因为这些高电离势（IP）谱线的产生对电离连续谱的形状敏感，而对于薄吸积盘而言，电离连续谱的形状依赖于黑洞质量。本研究探讨[Ne v]日冕线与SMBH质量之间的关联，分析斯皮策（Spitzer）光谱，样本包含27个SMBH质量跨度达三个数量级的AGN。在高信噪比下检测到[Ne v]14μm和[Ne v]24μm谱线后，通过高斯拟合测量日冕气体介质中的流量和电子密度；将谱线流量归一化为宽线区的宽氢伽马（Brγ_broad）发射。研究发现，[Ne v]14μm/Brγ_broad和[Ne v]24μm/Brγ_broad的线比与SMBH质量存在强相关性，27个AGN样本的散度分别为0.54和0.53 dex。这些相关性支持日冕气体激发因依赖电离连续谱形状而对一定范围SMBH质量敏感的理论；日冕介质的电子密度约为1000 cm⁻³，印证其核起源，与詹姆斯·韦布空间望远镜（JWST）对部分样本天体推导的密度值对比也证实了该结论。这些结果进一步证明CL可作为SMBH质量替代指标，实现AGN中SMBH质量的精确测量。
英文摘要
Coronal lines (CL) may be a reliable proxy of supermassive black hole (SMBH) masses in active galactic nuclei (AGN) because the production of these high ionisation potential (IP) lines is sensitive to the shape of the ionising continuum which, for a thin accretion disc, relies on the black hole mass. In this work we study the connection between the [Ne\,v] coronal lines and the SMBH mass. We analyse the \textit{Spitzer spectra} of a sample of 27 AGN spanning three orders of magnitude in SMBH mass. Fluxes and the electron density in the coronal gas medium were measured after fitting Gaussians to both the $\rm [Ne\,v]14μm$ and $\rm [Ne\,v]24μm$ lines where detected at high signal to noise. Line fluxes were normalised to the Br$γ_{\rm broad}$ emission from the broad line region. We found strong correlations between the $\rm [Ne\,v]14μm/Brγ_{\rm broad}$ and $\rm [Ne\,v]24μm/Brγ_{\rm broad}$ line ratios and the SMBH mass. For this sample of 27 AGN we find scatters of 0.54 and 0.53 dex, respectively. These correlations support the theory that the coronal gas excitation is sensitive to a range of SMBH masses because of the dependence on the shape of the ionising continuum. The electron densities of the coronal medium are of the order 1000$\rm cm^{-3}$ supporting their nuclear origin. A comparison with density values derived from JWST for a subsample of objects confirm this conclusion. These results further demonstrate the ability to use CL as a SMBH mass proxy, allowing for accurate SMBH mass measurements in AGN.
