Challenging the AGN scenario for JWST/NIRSpec LRD and non-LRD broad H$α$ emitters in light of non-detection of NIRCam photometric variability and X-ray
JWST has uncovered a substantial population of high-$z$ ($z \gtrsim 4$) galaxies exhibiting broad H$α$ emission line with a Full Width at Half Maximum exceeding 1,000 km/s. This population consists of a well-known subset called Little Red Dots (LRDs) and the remaining non-LRDs. If all of these broad H$α$ emitters were attributed to type $1-1.9$ Active Galactic Nuclei (AGNs), it would imply a significantly higher number density of low-luminosity AGNs than extrapolated from that of more luminous AGNs. Here, we have examined the rest-frame ultraviolet (UV)-optical flux variability of three LRD and two non-LRD broad H$α$ emitters using multi-epoch, multi-band JWST/NIRCam imaging data. The rest-frame temporal sampling interval of the NIRCam data ($\sim 400-500$~days$/(1+z)$) is comparable to typical variability timescales of AGNs with black hole (BH) masses of $M_{\text{BH}} \sim 10^{7}~M_{\odot}$; thus, the flux variations should be detectable if AGNs were present. However, no measurable flux variation over the rest-frame wavelength range of $λ_{\text{rest}} \sim 1,500-9,000$Å has been detected, placing stringent upper limits on the variability amplitudes. This result, combined with the X-ray faintness confirmed by the ultra-deep Chandra data, indicates that, under the AGN scenario, we need to postulate peculiar Compton-thick broad-line AGNs with either ($a$) an intrinsically non-variable AGN disk continuum, ($b$) a host galaxy-dominated continuum, or ($c$) scattering-dominated AGN emission. Alternatively, ($d$) they could be non-AGNs where the broad-line emission originates from unusually fast and dense/low-metallicity star-formation-driven outflows or inelastic Raman scattering of stellar UV continua by neutral hydrogen atoms.
Back to basics: Little Red Dots as galaxies and dust-obscured AGNs in a synthetic NIRCam sky simulated with L-GalaxiesBH
Donostia International Physics Centre (DIPC)（多诺斯蒂亚国际物理中心）；University of the Basque Country UPV/EHU（巴斯克国立大学）；Como Lake Center for AstroPhysics, University of Insubria（因斯布鲁克大学科莫湖天体物理中心）；Dipartimento di Fisica “G. Occhialini”, Università degli Studi di Milano-Bicocca（米兰比可卡大学 G. Occhialini 物理系）；INFN, Sezione di Milano-Bicocca（意大利国家核物理研究所米兰比可卡分部）；Key Laboratory for Computational Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台计算天体物理学重点实验室）；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）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（加泰罗尼亚高等研究学院，西班牙国家科研委员会））
A Population of Red Galaxies with Very Strong Emission Lines at $z > 5$ Revealed by the NIRCam Medium Bands: ''Classic'' LRDs, Dusty Star-Forming Galaxies, and a Missing Population of LRDs
York University（约克大学）；NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；The Catholic University of America（美利坚天主教大学）；National Research Council of Canada, Herzberg Astronomy & Astrophysics Research Centre（加拿大国家研究委员会赫茨伯格天文学与天体物理学研究中心）；INAF - Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；Dunlap Institute for Astronomy and Astrophysics（邓普尔天文学与天体物理学研究所）
利用NIRCam中波段成像在$4.9 \lesssim z \lesssim 8.9$处识别出具有强发射线的红色星系（REG），将其分为经典LRD、尘埃恒星形成星系和紧凑REG三类，并发现紧凑REG因多种原因被经典LRD选择标准遗漏。
NEXUS: Abundance, Environments, and Spectral Diversity of Little Red Dots from the NIRSpec MSA Sample
Department of Astronomy, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校天文学系）；National Center for Supercomputing Applications, University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校国家超级计算应用中心）；Department of Astronomy, University of Michigan（密歇根大学天文学系）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理学系）；UC San Diego（加州大学圣地亚哥分校）
OCEANS of Absorption: High-resolution NIRSpec Spectroscopy Reveals Diverse Balmer-line Absorption in Little Red Dots
University of Connecticut（康涅狄格大学）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Providence College（普罗维登斯学院）；University of the Pacific（太平洋大学）；Center for Space Sciences and Technology, UMBC（UMBC太空科学与技术中心）；Astrophysics Science Division, NASA Goddard Space Flight Center（NASA戈达德太空飞行中心天体物理学科学部）；University of Kansas（堪萨斯大学）；The Pennsylvania State University（宾夕法尼亚州立大学）
The Structure and Evolution of LRDs: Insights from JWST NIRSpec Medium and High Resolution Spectroscopy at $z\sim4$
University of Chinese Academy of Sciences (UCAS)（中国科学院大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与前沿科学研究院）；Chinese Academy of Sciences South America Center for Astronomy（中国科学院南美天文中心）；Key Laboratory of Optical Astronomy, NAOC（中国科学院国家天文台光学天文重点实验室）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）
From "The Cliff" to "Virgil": Mapping the Spectral Diversity of Little Red Dots with JWST/NIRSpec
University of the Pacific（太平洋大学）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙高等科学研究委员会-国家航空航天技术研究所）；Colby College（科尔比学院）；University of Connecticut（康涅狄格大学）；NSF National Optical-Infrared Astronomy Research Laboratory（美国国家光学红外天文研究实验室）；Center for Space Sciences and Technology, UMBC（太空科学与技术中心，马里兰大学巴尔的摩分校）；Astrophysics Science Division, NASA Goddard Space Flight Center（NASA戈达德太空飞行中心天体物理学部）；Institute for Astronomy, University of Edinburgh（爱丁堡大学天文学研究所）
The THRILS Factor: Investigating the properties of Little Red Dots (LRDs) at 3<z<6 with JWST/NIRSpec
The Johns Hopkins University（约翰斯·霍普金斯大学）；Space Telescope Science Institute（太空望远镜科学研究所）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；University of the Pacific（太平洋大学）
I present an overview of the JWST Advanced Deep Extragalactic Survey (JADES), a joint program of the JWST/NIRCam and NIRSpec Guaranteed Time Observations (GTO) teams involving 950 hours of observation. We will target two well-studied fields with excellent supporting data (e.g., from HST-CANDELS): GOODS-North and South, including the Ultra Deep Field. The science goal of JADES is to chart galaxy evolution at z > 2, and potentially out to z > 10, using the rest-frame optical and near-IR though observations from $\approx$ 1 - 5 $μ$m. Multi-colour NIRCam imaging with 9 filters will enable photomet…
Spatial decomposition of Little Red Dots with JWST/NIRSpec IFU into broad-line red cores and narrow-line blue host galaxies
Massachusetts Institute of Technology（麻省理工学院）；University of Hawai‘i（夏威夷大学）；Institute of Science and Technology Austria (ISTA)（奥地利科学技术研究所）；North Carolina State University（北卡罗来纳州立大学）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Princeton University（普林斯顿大学）
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）
An (in)complete NIRSpec census of Balmer absorption in Type 1 AGN -- radiation-driven outflows in little red dots, quasars and variable stars
University of Cambridge（剑桥大学）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）；Cavendish Laboratory, University of Cambridge（剑桥大学卡文迪许实验室）；University College London（伦敦大学学院）
NEXUS: A Search for Nuclear Variability with the First Two JWST NIRCam Epochs
University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign（美国国家超级计算应用中心，伊利诺伊大学厄巴纳-香槟分校）；Carnegie Mellon University（卡内基梅隆大学）；Space Telescope Science Institute（太空望远镜科学研究所）；UC San Diego（加州大学圣地亚哥分校）；Princeton University（普林斯顿大学）；University of California, Los Angeles（加州大学洛杉矶分校）
A Comprehensive JWST/NIRSpec Census of Broad-line Active Galactic Nuclei: Faint, Low-mass Accretors and a Population of Little Red Dots
New York University（纽约大学）；Menlo School（门洛学校）；Center for Interdisciplinary Exploration & Research in Astrophysics (CIERA)（天体物理跨学科探索与研究中心）；Northwestern University（西北大学）
ATLAS. II. Extremely High Incidence of Balmer Line Absorption with Predominant Blueshifts in LRDs: Statistical Insights through Comparison with Type 1 AGNs
Institute for Cosmic Ray Research, The University of Tokyo（东京大学宇宙射线研究所）；Department of Physics, Graduate School of Science, The University of Tokyo（东京大学理学研究科物理系）；National Astronomical Observatory of Japan（日本国立天文台）；Astronomical Science Program, Graduate Institute for Advanced Studies, SOKENDAI（SOKENDAI高级研究院天文学科学项目）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo（东京大学 Kavli宇宙物理数学研究所（WPI））
BlackTHUNDER: Shedding light on a dormant and extreme little red dot at z=8.50
University of Cambridge（剑桥大学）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）；Cavendish Laboratory, University of Cambridge（剑桥大学卡文迪许实验室）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；Department of Physics and Astronomy, University College London（伦敦大学学院物理与天文系）；Università degli Studi di Firenze（佛罗伦萨大学）；Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze（佛罗伦萨大学物理与天文系）；INAF - Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切尔蒂天文台）
Abundant Population of Broad H$α$ Emitters in the GOODS-N Field Revealed by CONGRESS, FRESCO, and JADES
Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；Department of Astronomy, Tsinghua University（清华大学天文系）；Space Telescope Science Institute（太空望远镜科学研究所）；Department of Physics, University of Oxford（牛津大学物理系）；European Space Agency (ESA), European Space Astronomy Centre (ESAC)（欧洲空间局（ESA）欧洲空间天文中心（ESAC））；Department of Astronomy & Astrophysics, The Pennsylvania State University（宾夕法尼亚州立大学天文与天体物理系）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）
The GlimmIr: Spectroscopic Variability in a z~7 LRD Indicates Rapid Changes in Both the Narrow and Broad Line Regions
NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；University of Maryland, College Park（马里兰大学帕克分校）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC（NASA/GSFC空间科学与技术探索研究中心）；Space Telescope Science Institute（太空望远镜科学研究所）；Center for Space Sciences and Technology, UMBC（马里兰大学巴尔的摩县分校空间科学与技术中心）
Little Red Dots at z~2 in EIGER reveal a gentle decline with respect to their peak number density at z~5
Institute of Science and Technology Austria（奥地利科学技术研究院）；North Carolina State University（北卡罗来纳州立大学）；Princeton University（普林斯顿大学）；National Astronomical Observatory of Japan（日本国立天文台）；Massachusetts Institute of Technology（麻省理工学院）；EPFL（洛桑联邦理工学院）
UV-to-optical insights into the BH$^*$ model in little red dots
Saint Mary’s University（圣玛丽大学）；National Research Council of Canada, Herzberg Astronomy & Astrophysics Research Centre（加拿大国家研究委员会赫茨伯格天体物理学与天文学研究中心）；Universidad Nacional de Córdoba（科尔多瓦国立大学）；Columbia University（哥伦比亚大学）
Detection of new galaxy candidates at z > 11 in the JADES field using JWST NIRCam
Department of Physics, University of Arkansas（阿肯色大学物理系）；Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理与空间研究研究所）；Stony Brook University（石溪大学）
ATLAS. I. A Scaling Relation of LRDs between Broad H$α$ and Bolometric Luminosities: Enhanced Broad H$α$ Emission Relative to Low-$z$ Type 1 AGN
Institute for Cosmic Ray Research, The University of Tokyo（东京大学宇宙线研究所）；Department of Physics, Graduate School of Science, The University of Tokyo（东京大学理学研究科物理学系）；National Astronomical Observatory of Japan（日本国立天文台）；Astronomical Science Program, Graduate Institute for Advanced Studies, SOKENDAI（SOKENDAI高等研究院天文学科学项目）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo（东京大学 Kavli宇宙物理数学研究所（WPI））
ATLAS. IV. A JWST+MUSE Demographic Study of Ly$α$ Profiles in Little Red Dots
The University of Tokyo（东京大学）；National Astronomical Observatory of Japan（日本国立天文台）；SOKENDAI（综合研究大学院大学）；Kavli Institute for the Physics and Mathematics of the Universe (WPI)（宇宙物质与宇宙 Kavli 研究所）
NEXUS: Spectral Variability of Little Red Dots and Blue Active Galactic Nuclei at $2 \lesssim z \lesssim 6$
University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign（美国国家超级计算应用中心）；Princeton University（普林斯顿大学）；University of Michigan（密歇根大学）
Origins of the UV continuum and Balmer emission lines in Little Red Dots: observational validation of dense gas envelope models enshrouding the AGN
Dunlap Institute for Astronomy and Astrophysics（邓普天文学与天体物理研究所）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学柯夫利天文学与天体物理研究所）；David A. Dunlap Department of Astronomy and Astrophysics, University of Toronto（多伦多大学大卫·A·邓普普天文学与天体物理学系）；NRC Herzberg（国家研究委员会赫茨伯格研究所）
Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）
A Nitrogen-rich AGN Powering a Large Ionizing Bubble at z=8.63
California Institute of Technology（加州理工学院）；Tohoku University（东北大学）；Space Telescope Science Institute（太空望远镜科学研究所）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；University of Ljubljana（卢布尔雅那大学）；Institute for Fundamental Physics of the Universe（基础物理宇宙研究所）；Johns Hopkins University（约翰斯·霍普金斯大学）；Università degli Studi di Milano（米兰大学）；INAF - IASF Milano（意大利国家天体物理研究所-米兰天文物理研究所）；NRC Herzberg（赫茨伯格国家研究委员会）
The X-Ray Dot: Exotic Dust or a Late-Stage Little Red Dot?
Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Center for Astrophysics, Harvard & Smithsonian（哈佛与史密森尼天体物理中心）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理学系）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Department of Physics, University of Oxford（牛津大学物理系）
The metallicities of little red dot host galaxies: LRDs are metal poor, but not pristine
Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Department of Astronomy, University of Geneva（日内瓦大学天文学系）
利用 JWST/NIRSpec 光谱数据，通过直接 Te 方法测量 24 个小红点（LRD）宿主星系的气相金属丰度，发现其平均金属丰度约为 0.08 太阳丰度，属于贫金属但非原始星系，挑战了原始气体塌缩模型。
SPURS: Evidence for Clumpy Neutral Envelopes and Ionized IGM Surrounding Little Red Dots in Abell 2744 from Ultra-Deep Rest-UV Spectroscopy
Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交大李政道研究所）；School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）；State Key Laboratory of Dark Matter Physics, Shanghai Jiao Tong University（上海交通大学暗物质全国重点实验室）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯玻尔研究所）；Department of Astronomy & Astrophysics, University of Chicago（芝加哥大学天文与天体物理系）；Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙物理学研究所）；Centre for Astronomy of Heidelberg University, Astronomisches Rechen-Institut（海德堡大学天文中心计算天文研究所）
通过超深rest-UV光谱研究，发现Abell 2744中Little Red Dots周围存在致密中性包层和电离IGM，揭示其可能通过密集环境形成Lyα发射。
VENUS: When Red meets Blue -- A multiply imaged Little Red Dot with an apparent blue companion behind the galaxy cluster Abell 383
Ben-Gurion University of the Negev（内盖夫本-古里安大学）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；University of Toronto（多伦多大学）；Dunlap Institute for Astronomy and Astrophysics（邓普勒天文学与天体物理学研究所）；Indiana University（印第安纳大学）
Implications of Broad [O III] 4364 and UV Line Emission in Two Little Red Dots at z ~ 7 - 8
Texas A&M University（德克萨斯农工大学）；George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University（乔治·P和辛西娅·伍兹基础物理与天文学研究所，德克萨斯农工大学）；Colby College（科尔比学院）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）
The ionizing properties of JWST's compact broad-line emitters
Institute of Science and Technology Austria (ISTA)（奥地利科学技术研究所）；Princeton University（普林斯顿大学）；Massachusetts Institute of Technology（麻省理工学院）；MIT Kavli Institute for Astrophysics and Space Research（麻省理工学院卡弗里天体物理学与空间研究研究所）；University of Hawai’i（夏威夷大学）
Skyfire: A Spectroscopic Census of Little Red Dots and Broad-Line AGN in the CEERS Field
Colby College（科尔比学院）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Cosmic Frontier Center, The University of Texas at Austin（宇宙前沿中心，德克萨斯大学奥斯汀分校）；Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), The University of Tokyo（东京大学宇宙物理与数学研究所（Kavli IPMU，WPI））；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；University of the Pacific（太平洋大学）；Peking University（北京大学）；Astrophysics Science Division, NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心天体物理学部）；University of Connecticut（康涅狄格大学）；Space Telescope Science Institute（空间望远镜科学研究所）
Pseudo Little Red Dot: an Active Black Hole Embedded in a Dense and Dusty, Metal-Poor Starburst Galaxy at z=5.96
Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；Space Telescope Science Institute（太空望远镜科学研究所）；Institute of Science and Technology Austria (ISTA)（奥地利科学技术研究所）
