由强大电离外流驱动的类星体中的尘埃-射电关联
Radio-dust connection in quasars driven by powerful ionised outflows
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中文总结 AI 辅助
该研究利用DESI类星体样本和LoTSS射电数据，发现类星体射电-尘埃关联由高速电离外流驱动，外流与中红外超量相关，而非单纯尘埃消光。
中文摘要 AI 辅助
尘埃类星体的反馈被认为是星系演化的关键驱动因素。多项研究报告称类星体中尘埃消光与射电辐射之间存在关联，这可能源于风或喷流与星际介质的相互作用。我们利用暗能量光谱仪（DESI）的光学光谱，测试电离外流是否能驱动观测到的尘埃-射电关联，并确定尘埃和/或颜色是否在产生类星体高速电离外流中发挥作用。基于0.5 < z < 0.9的3418个DESI类星体样本，我们通过PyQSOFit拟合光谱来约束[OIII]λ5007的运动学，并比较[OIII]外流速度与视线尘埃消光E(B-V)、光学-中红外（MIR）颜色g-W2、L6μm/L5100A（中红外超量的代理）之间的观测趋势。利用LOFAR两米巡天（LoTSS）DR2的射电数据，我们还探究了射电、尘埃和外流之间的关联。我们发现射电辐射与尘埃遮蔽之间的关联由拥有高速电离外流的源驱动。然而，我们未发现[OIII]外流速度与E(B-V)之间存在显著趋势，这表明仅尘埃消光并非决定类星体是否拥有强大电离外流的重要因素。另一方面，即使在控制光度后，我们仍发现g-W2与外流速度之间存在明确的正相关。我们认为这是由于中红外超量（增强W2波段）与外流之间存在关联，而L6μm/L5100A与外流速度之间的正相关支持了这一点。我们的结果指向一种情景：外流冲击周围的尘埃和气体，加热尘埃并增强中红外和射电辐射。
英文摘要
Feedback from dusty quasars is thought to be a key driver in galaxy evolution. Multiple studies have reported a link between dust extinction and radio emission in quasars, possibly attributed to winds or jets interacting with the interstellar medium. We use optical spectra from the Dark Energy Spectroscopic Instrument (DESI) to test whether ionised outflows could be driving the observed radio-dust connection and to determine whether dust and/or colour play a role in producing high-velocity ionised outflows in quasars. Based on a sample of 3418 DESI quasars at 0.5 < z < 0.9, we constrained the [OIII]$λ$5007 kinematics by fitting the spectra with PyQSOFit and comparing the observed trends among the [OIII] outflow velocity and the line-of-sight dust extinction E(B-V), optical-to-mid-infrared (MIR) colour g-W2, and L6$μ$m/L5100A (a proxy for MIR excess). Utilising radio data from the LOFAR Two-metre Sky Survey (LoTSS) DR2, we also explored the link between radio, dust, and outflows. We find that the link between radio emission and dust obscuration is driven by sources hosting high-velocity ionised outflows. However, we find no significant trend between the [OIII] outflow velocity and E(B-V), which suggests dust extinction alone is not a significant factor in determining whether a quasar hosts a powerful ionised outflow. On the other hand, we find a clear positive trend between g-W2 and outflow velocity, even after controlling for luminosity. We suggest this is due to a connection between a MIR excess (boosting the W2 band) and outflows, which is supported by a positive trend between L6$μ$m/L5100A and outflow velocity. Our results point to a scenario in which outflows shock the surrounding dust and gas, heating the dust and boosting both the MIR and radio emission.
发表机构
- European Southern Observatory (ESO)（欧洲南方天文台）
- Newcastle University（纽卡斯尔大学）
- Durham University（杜伦大学）
- Max-Planck-Institut für Extraterrestrische Physik（马克斯·普朗克地外物理研究所）
- University of Oxford（牛津大学）
- Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文研究所）
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