A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems
A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems
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红外类星体的全色视图：在最严重遮挡的系统中过量的恒星形成和射电发射
DOI：
10.1093/mnras/stac2800
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发表时间：
2022
影响因子：
4.8
通讯作者：
Andonie C
中科院分区：
文献类型：
--
作者：
Andonie C
为了了解活动星系核（AGN）现象及其对星系演化的影响，需要进行一次完整的AGN普查;然而，发现严重模糊的AGN在观测上具有挑战性。在这里，我们使用COSMOS领域的深度和广泛的多波长数据来选择578个红外（IR）类星体的完整样本，具有最小的遮蔽偏差，使用详细的UV到远IR光谱能量分布（SED）拟合。我们补充我们的SED约束与X射线和无线电观测，以进一步研究样品的属性。总的来说，Chandra探测到了322个红外类星体，它们具有各自的X射线光谱限制。从X射线叠加和分析的组合，我们表明，大多数的X射线微弱和未检测到的类星体是严重模糊的（许多可能是康普顿厚），突出中红外波段的有效性，找到模糊的活动星系核。我们发现355个（约61%）红外类星体被遮蔽（），并确定遮蔽和未遮蔽类星体之间的平均性质的差异：（1）遮蔽类星体的星星形成率比未遮蔽系统高1.3倍，恒星质量没有显着差异;（2）遮蔽类星体比未遮蔽系统有更强的无线电发射，无线电响度参数更高。这些结果是不一致的一个简单的取向模型，但在一般协议要么极端的主机星系对被遮蔽的类星体或一个场景，被遮蔽的类星体是一个早期阶段的类星体的演化。
To understand the active galactic nuclei (AGNs) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and extensive multiwavelength data in the COSMOS field to select a complete sample of 578 infrared (IR) quasars () atz< 3, with minimal obscuration bias, using detailed UV-to-far-IR spectral energy distribution (SED) fitting. We complement our SED constraints with X-ray and radio observations to further investigate the properties of the sample. Overall, 322 of the IR quasars are detected byChandraand have individual X-ray spectral constraints. From a combination of X-ray stacking and–analyses, we show that the majority of the X-ray faint and undetected quasars are heavily obscured (many are likely Compton thick), highlighting the effectiveness of the mid-IR band to find obscured AGNs. We find that 355 (≈61 per cent) IR quasars are obscured () and identify differences in the average properties between the obscured and unobscured quasars: (1) obscured quasars have star formation rates ≈3 times higher than unobscured systems for no significant difference in stellar mass and (2) obscured quasars have stronger radio emission than unobscured systems, with a radio-loudness parameterhigher. These results are inconsistent with a simple orientation model but in general agreement with either extreme host-galaxy obscuration towards the obscured quasars or a scenario where obscured quasars are an early phase in the evolution of quasars.
FortesFit：具有贝叶斯主干的灵活光谱能量分布建模
DOI：
--
发表时间：
2019
期刊：
影响因子：
--
作者：
D. Rosario
通讯作者：
D. Rosario