One of the key open questions in cosmology today pertains to understanding when, where and how super massive black holes form, while it is clear that mergers likely play a significant role in the growth cycles of black holes, how supermassive black holes form, and how galaxies grow around them. Here, we present Hubble Space Telescope WFC3/IR grism observations of a clumpy galaxy at z=1.35, with evidence for 10^6 - 10^7 Msun rapidly growing black holes in separate sub-components of the host galaxy. These black holes could have been brought into close proximity as a consequence of a rare multiple galaxy merger or they could have formed in situ. Such holes would eventually merge into a central black hole as the stellar clumps/components presumably coalesce to form a galaxy bulge. If we are witnessing the in-situ formation of multiple black holes, their properties can inform seed formation models and raise the possibility that massive black holes can continue to emerge in star-forming galaxies as late as z=1.35 (4.8 Gyr after the Big Bang).
The evolution of the luminosity function (LF) of Active Galactic Nuclei (AGNs) at $z \gtrsim 5$ represents a key constraint to understand their contribution to the ionizing photon budget necessary to trigger the last phase transition in the Universe, i.e. the epoch of Reionization. Recent searches for bright high-z AGNs suggest that the space densities of this population at $z>4$ has to be revised upwards, and sparks new questions about their evolutionary paths. Gas accretion is the key physical mechanism to understand both the distribution of luminous sources and the growth of central Super-M…
This is the second paper in a series aimed at modeling the black hole (BH) mass function, from the stellar to the (super)massive regime. In the present work we focus on (super)massive BHs and provide an ab-initio computation of their mass function across cosmic times. We consider two main mechanisms to grow the central BH, that are expected to cooperate in the high-redshift star-forming progenitors of local massive galaxies. The first is the gaseous dynamical friction process, that can cause the migration toward the nuclear regions of stellar-mass BHs originated during the intense bursts of st…
We explore the effect of dust on the growth of seed black holes (BHs) in the early universe. Previous 1D radiation-hydrodynamic (RHD) simulations show that increased radiation pressure on dust further suppresses the accretion rate than the case for the chemically pristine gas. Using the Enzo+Moray code, we perform a suite of 3D RHD simulations of accreting BHs in a dusty interstellar medium (ISM). We use the modified Grackle cooling library to consider dust physics in its non-equilibrium chemistry. The BH goes through an early evolutionary phase, where ionizing BH radiation creates an oscillat…
We explore the observational implications of a model in which primordial black holes (PBHs) with a broad birth mass function ranging in mass from a fraction of a solar mass to $\sim$10$^6$ M$_{\odot}$, consistent with current observational limits, constitute the dark matter component in the Universe. The formation and evolution of dark matter and baryonic matter in this PBH-\LambdaCDM~Universe are presented. In this picture, PBH DM mini-halos collapse earlier than in standard \LambdaCDM, baryons cool to form stars at $z\sim15-20$, and growing PBHs at these early epochs start to accrete through…
A Dark-matter Origin of Little Red Dots: Early Seeding and Super-Bondi Accretion
Peking University（北京大学）；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）；Beijing Normal University（北京师范大学）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）；University of Chinese Academy of Sciences（中国科学院大学）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
Formation of Heavy Seed Black Holes and Little Red Dots-like Compact Clusters in Metal-enriched Star-forming Regions
Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Astronomical Institute, Graduate School of Science, Tohoku University（东北大学理学研究科天文学系）；Department of Applied Physics, Faculty of Engineering, Kanagawa University（神奈川大学工学部应用物理系）；Department of Astronomy, School of Science, University of Tokyo（东京大学理学部天文学系）；Academia Sinica, Institute of Astronomy and Astrophysics（中央研究院天文及天文物理研究所）；Heidelberger Institut für Theoretische Studien（海德堡理论研究所）
Black Hole Feedback, Galaxy Quenching and Outflows at Cosmic Dawn: Analysis of the SEEDZ Simulations
Maynooth University（梅努斯大学）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；University of Cambridge（剑桥大学）；Universität Heidelberg（海德堡大学）；Georgia Institute of Technology（佐治亚理工学院）；University College Cork（科克大学学院）；Cardiff University（卡迪夫大学）；University of Edinburgh（爱丁堡大学）
More Numerous and Bluer: Companions of the Brightest Little Red Dots Differ from Control Galaxies at $>3σ$, Hinting at Synchronized Black Hole Seed Formation
The Little Red Dots Are Direct Collapse Black Holes
Black Hole Initiative, Harvard University（哈佛大学黑洞倡议项目）；Scuola Normale Superiore（比萨高等师范学院）；Department of Physics and Astronomy, Colby College（科尔比学院物理与天文系）
