本文介绍了一个JVLA试验项目的结果,该项目旨在研究由NVSS/FIRST和SDSS巡天所揭示的大部分射电活动星系核,我们在JVLA获得了1.4,4.5和7.5 GHz的SDSS/NVSS样品的12个源的A-阵列观测。射电图显示了1 - 3千秒差距尺度上的致密的未分辨或略分辨的射电结构,只有一个例外,即一个FRI/FRII源延伸超过$\sim$ 40千秒差距。我们分离了大多数的无线电核心部件。样本分为两组。有四个来源有小黑洞(BH)质量(大多数是$\sim$ 10 $^{7}$ M $_{\odot}$),并由蓝色星系托管,经常显示出从恒星形成到其射电辐射的污染证据,并与无线电安静的活动星系核有关。第二组由7个射电强活动星系核组成,它们生活在红色大质量($\sim10^{11}$ M $_{\odot}$)的早型星系中,具有大BH质量($\gtrsim$ 10 $^{8}$ M $_{\odot}$),光谱分类为低激发星系,所有特征都是FRI射电星系的典型特征。它们也依赖于FRIs定义的射电核心功率和[O III]线光度之间的相关性。然而,它们比FRIs更受核心支配(因子为$\sim$ 30),并表现出扩展射电发射的不足。我们称这些源为"FR 0",以强调它们缺乏突出的扩展无线电发射,相对于FRIs的唯一区别特征。FR 0和FRIs之间的无线电特性的差异可能归因于进化效应,FR 0源经历快速的不稳定性,防止大尺度结构的生长。在我们的首选方案中,FR 0中缺乏扩展的无线电发射是由于它们相对于FRI较小的喷流洛伦兹$Γ$因子,从而导致可能的不稳定性和过早的破坏。[删节]
英文摘要:
We present the results of a pilot JVLA project aimed at studying the bulk of the radio-emitting AGN population, unveiled by the NVSS/FIRST and SDSS surveys.We obtained A-array observations at the JVLA at 1.4, 4.5, and 7.5 GHz for 12 sources of the SDSS/NVSS sample. The radio maps reveal compact unresolved or slightly resolved radio structures on a scale of 1-3 kpc, with only one exception of a FRI/FRII source extended over $\sim$40 kpc. We isolate the radio core component in most of them. The sample splits into two groups. Four sources have small black hole (BH) masses (mostly $\sim$10$^{7}$ M$_{\odot}$) and are hosted by blue galaxies, often showing evidence of a contamination from star formation to their radio emission and associated with radio-quiet AGN. The second group consists in seven radio-loud AGN, which live in red massive ($\sim10^{11}$ M$_{\odot}$) early-type galaxies, with large BH masses ($\gtrsim$10$^{8}$ M$_{\odot}$), and spectroscopically classified as Low Excitation Galaxies, all characteristics typical of FRI radio galaxies. They also lie on the correlation between radio core power and [O III] line luminosity defined by FRIs. However, they are more core dominated (by a factor of $\sim$30) than FRIs and show a deficit of extended radio emission. We dub these sources 'FR0' to emphasize their lack of prominent extended radio emission, the single distinguishing feature with respect to FRIs. The differences in radio properties between FR0s and FRIs might be ascribed to an evolutionary effect, with the FR0 sources undergoing to rapid intermittency that prevents the growth of large scale structures. In our preferred scenario the lack of extended radio emission in FR0s is due to their smaller jet Lorentz $Γ$ factor with respect to FRIs, causing possible instabilities and their premature disruption.[abridged]
Revised optical classification of a sample of gamma-ray emitting AGN with GTC and VLT
Università degli studi dell’Insubria(因苏布里亚大学);Osservatorio Astronomico di Brera, Istituto Nazionale di Astrofisica (INAF)(布雷拉天文台,意大利国家天体物理研究所);European Southern Observatory (ESO)(欧洲南方天文台);Texas Tech University(德克萨斯理工大学);Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica (INAF)(帕多瓦天文台,意大利国家天体物理研究所);Università degli studi di Padova(帕多瓦大学);University of Central Lancashire(中央兰开夏大学);Osservatorio Astronomico di Cagliari, Istituto Nazionale di Astrofisica (INAF)(卡利亚里天文台,意大利国家天体物理研究所);Universidade de Coimbra(科英布拉大学);University College London(伦敦大学学院);Università di Roma Tor Vergata(罗马二大);Universidad Diego Portales(迭戈·波特莱斯大学)
The line parameters and ratios as the physical probe of the line emitting regions in AGN
本文讨论了活动星系核(AGN)发射线区(ELR)的物理条件,特别强调了尚未解决的问题,如宽线区(BLR)的分层或光电离不能解释观测到的强光学Fe II发射。在这里,我们使用不同的线通量,以探测ELR的属性,如氢巴耳末线(Ha到He),氦线从两个随后的电离水平(He II 4686和He I 5876)和最强的Fe II线在波长范围4400-5400 nm。我们发现,氢巴耳末和氦线可以用于估计的物理参数的BLR,我们表明,Fe II发射主要是从中间线区域(ILR),这是位于更远离中央连续源比BLR。
Coronal-Line Forest AGN: the best view of the inner edge of the AGN torus?
我们介绍冕线森林活动星系核(CLiF AGN),AGN具有丰富的禁止高电离线(FHILs,例如[FeVII],[FeX]和[NeV]),以及相对较强的窄($\sim$ 300 km s $^{-1}$)H $α$发射相比,其他巴耳末过渡线。我们发现,CLiF发射区的运动学是类似的禁戒低电离发射线(FLIL)区域。我们将FHIL和FLIL的发射线强度与CLOUDY光电离结果进行比较,发现当与FLIL发射区(10 $^{3.0}$ $<$ n $_H$ $<$ 10 $^{7.5}$ cm $^{-3}$)相比时,CLiF发射区具有更高的密度(10 $^{4.5}$ $<$ n $_H$ $<$ 10 cm $^{-3}$)。我们使用光电离的结果来计算CLiF区域的径向距离(0.04 $<$ R $_{CLiF}$ $<$ 32.5 pc),并发现它们是可比的尘埃颗粒升华距离(0.10 $<$ R $_{SUB}$ $<$ 4.3 pc)。因此,我们认为,内环面壁是最有可能的位置的CLiF区域,和不寻常的强度的FHILs是由于一个特定的视角给出了一个最大的视图的远壁的环面没有连续被发现。
The FeII emission in active galactic nuclei: excitation mechanisms and location of the emitting region
我们提出了一个研究FeII发射在近红外区域(NIR)的25个活动星系核(AGN),以获得有关的激励机制,它的权力和它的形成位置的信息。我们采用了近红外FeII模板来自文献中,发现它成功地再现了所观察到的FeII光谱。在所研究的所有物体中检测到的9200埃的FeII碰撞证实了活动星系核中总是存在莱曼α荧光。9200埃凸点的通量、1微米线和光学Fe II之间的相关性表明,莱曼α荧光在Fe II的产生中起着重要作用。我们确定至少18%的光学FeII是由于这个过程,而碰撞激发在观察到的FeII的产生中占主导地位。比较Fe II 10502、OI 11287、Ca II 8664和Paschen-beta的谱线轮廓,以收集关于它们最可能发射的位置的信息。我们发现,FeII,OI和CaII具有相似的宽度,平均比Paschen-beta窄30%。假设发射线的云是维里化的,我们表明,FeII是在一个区域的两倍远的中央源比Paschen-beta。距离变化很大:从NGC 4051的8.5光日到Mrk 509的198.2光日。我们的研究结果加强了FeII在NIR中的重要性,以限制驱动其物理和基本活动星系核运动学的关键参数,以及旨在再现这种复杂发射的更准确的模型。
AGN Feedback and the Development of Dusty Multiphase Gas in X-ray Emitting Elliptical Galaxies
NASA - Ames Research Center(美国国家航空航天局艾姆斯研究中心);Dipartimento di Fisica e Astronomia, Universita‘ di Bologna(博洛尼亚大学物理与天文学系);Istituto Nazionale di Astrofisica - Istituto di Radioastronomia (IRA)(意大利国家天体物理学研究所无线电天文研究所);University of California Observatories/Lick Observatory(加州大学观测站/利克天文台);Bay Area Environmental Research Institute(湾区环境研究所);Departamento de Física, Universidad de Santiago de Chile(智利圣地亚哥大学物理系);Center for Interdisciplinary Research in Astrophysics and Space Exploration (CIRAS), Universidad de Santiago de Chile(智利圣地亚哥大学天体物理学与空间探索跨学科研究中心);NASA Ames Research Center - Aviation Systems Division(美国国家航空航天局艾姆斯研究中心航空系统分部);Crown Consulting, Inc(皇冠咨询公司);Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia(摩德纳和雷焦艾米利亚大学物理、信息学与数学系)
A pilot VLBI study of the SQUAB quasar sample featuring multiple Gaia detections
Shanghai Astronomical Observatory, CAS(中国科学院上海天文台);State Key Laboratory of Radio Astronomy and Technology(射电天文学与技术国家重点实验室);CSIRO Space and Astronomy(澳大利亚联邦科学与工业研究组织空间与天文部);School of Astronomy and Space Sciences, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院)
Flagging Super-Eddington Candidates among Jetted, γ-Ray-Emitting AGN
Astronomical Observatory of Padova, National Institute for Astrophysics (INAF)(帕多瓦天文台,意大利国家天体物理研究所);Osservatorio Astronomico di Brera, Istituto Nazionale di Astrofisica (INAF)(布雷拉天文台,意大利国家天体物理研究所)
Simulating X-ray Reverberation in the UV-Emitting Regions of Active Galactic Nuclei Accretion Disks with 3D Multi-Frequency Magnetohydrodynamic Simulations
Probing Direct Contributions of Galaxies and AGN to Cosmic Reionization in a Quasar Field J0226+0302 with JWST NIRCam and NIRSpec
University of Michigan(密歇根大学);Steward Observatory, University of Arizona(亚利桑那大学斯图尔德天文台);Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen(哥本哈根大学尼尔斯·玻尔研究所黎明中心);Kavli IPMU (WPI), UTIAS, The University of Tokyo(东京大学宇宙起源研究核心理论研究中心);Center for Data-Driven Discovery, Kavli IPMU (WPI), UTIAS, The University of Tokyo(东京大学宇宙起源研究核心理论中心数据驱动发现中心);Department of Physics & Astronomy, University of California, Riverside(加州大学河滨分校物理与天文学系)