The nature of compact radio-loud AGN: A systematic look at the LOFAR AGN population
The nature of compact radio-loud AGN: A systematic look at the LOFAR AGN population
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紧凑型无线电响度 AGN 的本质：系统地观察 LOFAR AGN 群
DOI：
10.1093/mnras/stae658
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发表时间：
2024
影响因子：
4.8
通讯作者：
Chilufya J
中科院分区：
文献类型：
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作者：
Chilufya J
我们研究了从LOFAR两米巡天（LoTSS）第一次数据发布（DR 1）中选择的低光度射电大声活动星系核（RLAGN）的性质。利用光学、中红外和射电数据，我们保守地从DR 1中选出了55个红移范围为0.03 <z< 0.1的活动星系核候选者。我们使用高频卡尔G. Jansky甚大阵列（VLA）的观测表明，55个物体中有10个显示出大于1-3 kpc尺度的无线电发射，42个是紧凑的，极限分辨率为0.35 arcsec（对投影的物理大小取上限，这相当于小于1 kpc），还有3个未被发现。延伸的物体显示了广泛的射电形态：双喷流（5），单喷流（4）和双叶（1）。我们提出了所有检测到的无线电源的无线电频谱，其范围从陡峭到平坦/倒置，并跨越其他紧凑型无线电源，如紧凑对称物体（CSO），紧凑陡谱（CSS）源和千兆赫兹峰值频谱（GPS）源的范围。假设同步辐射自吸收（SSA）的平坦/倒置的无线电频谱源，我们预测小的物理尺寸紧凑的对象范围在2和53 pc之间。或者，使用自由-自由吸收（FFA）模型，我们估计了所有紧凑的对象，假设一个均匀的吸收体的自由电子柱深度。我们发现这些天体在功率/线性尺寸（P-D）图上并不占据特殊的位置，但在射电光度和线性尺寸方面，有些天体与射电宁静类星体（RQQs）和所谓的“FR 0”源共享一个区域。
We investigate the nature of low-luminosity radio-loud active galactic nuclei (RLAGN) selected from the LOFAR Two-metre Sky Survey (LoTSS) first data release (DR1). Using optical, mid-infrared, and radio data, we have conservatively selected 55 radiative AGN candidates from DR1 within the redshift range 0.03 <z< 0.1. We show using high-frequencyKarl G. JanskyVery Large Array (VLA) observations that 10 out of 55 objects show radio emission on scales >1–3 kpc, 42 are compact at the limiting resolution of 0.35 arcsec (taking an upper limit on the projected physical size, this corresponds to less than 1 kpc), and three are undetected. The extended objects display a wide range of radio morphologies: two-jet (5), one-jet (4), and double-lobed (1). We present the radio spectra of all detected radio sources which range from steep to flat/inverted and span the range seen for other compact radio sources such as compact symmetric objects (CSOs), compact steep spectrum (CSS) sources, and gigahertz peaked-spectrum (GPS) sources. Assuming synchrotron self-absorption (SSA) for flat/inverted radio spectrum sources, we predict small physical sizes for compact objects to range between 2 and 53 pc. Alternatively, using free–free absorption (FFA) models, we have estimated the free electron column depth for all compact objects, assuming a homogeneous absorber. We find that these objects do not occupy a special position on the power/linear size (P−D) diagram but some share a region with radio-quiet quasars (RQQs) and the so-called ‘FR0’ sources in terms of radio luminosity and linear size.