The radio structure of the narrow-line Seyfert 1 Mrk 783 with VLBA and e-MERLIN
The radio structure of the narrow-line Seyfert 1 Mrk 783 with VLBA and e-MERLIN
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DOI：
10.1093/mnras/staa3024
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发表时间：
2020-09
影响因子：
4.8
通讯作者：
E. Congiu;E. Congiu;P. Kharb;A. Tarchi;M. Berton;M. Berton;A. Caccianiga;S. Chen;L. Crepaldi;F. D. Mille;E. Järvelä;M. Jarvis;M. Jarvis;M. Jarvis;G. L. Mura;A. Vietri
中科院分区：
文献类型：
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作者：
E. Congiu;E. Congiu;P. Kharb;A. Tarchi;M. Berton;M. Berton;A. Caccianiga;S. Chen;L. Crepaldi;F. D. Mille;E. Järvelä;M. Jarvis;M. Jarvis;M. Jarvis;G. L. Mura;A. Vietri
在本文中，我们对窄线 Seyfert 1 星系 Mrk 783 的新射电和光学观测进行了分析。使用 e-MERLIN 干涉仪进行的 $1.6\, \mathrm{GHz}$ 观测证实了先前观测到的漫射发射的存在。甚长基线阵列 (VLBA) 还可检测 $1.6\, \mathrm{GHz}$ （L 波段）和 $5\, \mathrm{GHz}$ （C 波段）的核源。 L 波段图像仅显示未解析的核心，而 C 波段图像显示在 60° 位置角处存在部分解析的结构。两个波段的发射亮度温度 (${\gt}10^6\, \mathrm{K}$) 表明它是由活动星系核产生的 pc 级喷流。相对陡峭的 VLBA 光谱指数（αVLBA = 0.63 ± 0.03）与毫弧秒尺度上光学薄发射的存在一致。最后，我们研究了两种可能导致在星系中检测到的 kpc 和 pc 尺度射电结构之间不一致的情况。我们还分析了星系的光学形态，这表明 Mrk 783 在相对较近的时期经历了合并。
In this paper, we present the analysis of new radio and optical observations of the narrow-line Seyfert 1 galaxy Mrk 783. $1.6\, \mathrm{GHz}$ observations performed with the e-MERLIN interferometer confirm the presence of the diffuse emission previously observed. The Very Long Baseline Array (VLBA) also detects the nuclear source both at $1.6\, \mathrm{GHz}$ (L band) and $5\, \mathrm{GHz}$ (C band). While the L-band image shows only an unresolved core, the C-band image shows the presence of a partially resolved structure at a position angle of 60○. The brightness temperature of the emission in both bands (${\gt}10^6\, \mathrm{K}$) suggests that it is a pc-scale jet produced by the active galactic nucleus. The relatively steep VLBA spectral index (αVLBA = 0.63 ± 0.03) is consistent with the presence of optically thin emission on milliarcsecond scales. Finally, we investigated two possible scenarios that can result in the misalignment between the kpc and pc-scale radio structure detected in the galaxy. We also analysed the optical morphology of the galaxy, which suggests that Mrk 783 underwent a merging in relatively recent times.