论文标题
从衬里Galaxy NGC 4293中低质量AGN的紧凑型对称射血
A compact symmetric ejection from the low mass AGN in the LINER galaxy NGC 4293
论文作者
论文摘要
我们对Galaxy NGC 4293（$ z = 0.003 $）中低质量活性银河核（AGN）进行了很长的基线阵列（VLBA）。该物体与低离子化核发射线区域（衬里）有关。其黑洞质量估计为$ \ sim10^5 $或$ \ sim10^7 m_ \ odot $。 VLBA 1.5 GHz图像显示了一个反对称结构，其两个离散无线电斑点被$ \ sim120 $ mas的角距离分开，对应于$ \ sim7 $ parsec。此外，其集成的无线电频谱的频率为$ \ sim0.44 $ GHz。基于紧凑性和光谱，NGC 4293中的核无线电源属于（Megahertz）峰值光谱（PS/MPS）的无线电源，具有紧凑的对称形态。 NGC 4293的无线电功率仅为$ \ sim10^{20} \，\ mathrm {w \，hz^{ - 1}} $，带有VLBA观察，这与本地AGN一致，但低于当前PS样品。两个斑点之一具有陡峭的无线电频谱$α= -0.62 \ pm0.08 $（$s_ν\proptoν^{+α} $），而另一个具有反向频谱$α= 0.32 \ pm0.10 $。两个斑点的VLBA 1.5 GHz光度比为3.23，两个斑点显示侧向结构，其中热点位于每个无线电叶的边缘。这可以解释为与密集的周环介质的喷气相互作用。我们通过黑洞活动的基本平面估计NGC 4293的黑洞质量，该平面将黑洞质量限制为$ \ lysSim10^6 m_ \ odot $。它支持该对象是一个低质量AGN，也是吸收和弹出IMBH的潜在候选者。
We conducted a Very Long Baseline Array (VLBA) observation of the low mass active galactic nucleus (AGN) in galaxy NGC 4293 ($z=0.003$). The object is associated with a low-ionization nuclear emission-line region (LINER). Its black hole mass is estimated as $\sim10^5$ or $\sim10^7 M_\odot$. The VLBA 1.5 GHz image shows an inverse symmetric structure with two discrete radio blobs separated by an angular distance of $\sim120$ mas, corresponding to $\sim7$ parsec. Furthermore, its integrated radio spectrum has a turnover at the frequency of $\sim0.44$ GHz. Based on the compactness and spectrum, the nuclear radio source in NGC 4293 belongs to a sample of (megahertz) peaked spectrum (PS/MPS) radio sources with compact symmetric morphologies. NGC 4293 has 1.4 GHz radio power of only $\sim10^{20}\,\mathrm{W\,Hz^{-1}}$ with the VLBA observation, which is consistent with local AGNs but lower than the current PS samples. One of the two blobs has a steep radio spectrum $α=-0.62\pm0.08$ ($S_ν\proptoν^{+α}$), while the other one has an inverted spectrum $α=0.32\pm0.10$. The VLBA 1.5 GHz luminosity ratio of the two blobs is 3.23 and both blobs show lateral-flowing structures where the hotspots reside at the edge of each radio lobe. This can be explained as jet interactions with dense circumnuclear medium. We estimate the black hole mass of NGC 4293 through the fundamental plane of black hole activity, which constrains the black hole mass to be $\lesssim10^6 M_\odot$. It supports that the object is a low-mass AGN and a potential candidate for accreting and ejecting IMBHs.
