相关论文: Radiative effects during the assembly of direct co…
We assess the impact of trapped Lyman alpha cooling radiation on the formation of direct collapse black holes (DCBHs). We apply a one-zone chemical and thermal evolution model, accounting for the photodetachment of H- ions, precursors to…
We estimate the fraction of halos that host supermassive black holes (SMBHs) forming through the direct collapse (DC) scenario by using cosmological N -body simulations combined with a semi-analytic model for galaxy evolution. While in most…
`Direct collapse black holes' (DCBHs) provide possible seeds for supermassive black holes that exist at redshifts as high as z~7. We study Lyman Alpha (Lya) radiative transfer through simplified representations of the DCBH-scenario. We find…
The direct collapse (DC) is a promising mechanism that provides massive seed black holes (BHs) with $\sim 10^{5}~M_{\odot}$ in the early universe. To study a long-term accretion growth of a DCBH thus formed, we perform cosmological…
High-redshift quasar observations imply that supermassive black holes (SMBHs) larger than $\sim 10^9 ~ M_\odot$ formed before $z=6$. That such large SMBHs formed so early in the Universe remains an open theoretical problem. One possibility…
It has been proposed that the first, intermediate-mass ($\approx 10^{5-6}~M_\odot$) black holes might form through direct collapse of unpolluted gas in atomic-cooling halos exposed to a strong Lyman-Werner (LW) or near-infrared (NIR)…
Direct collapse black holes (DCBHs) formed from the collapse of atomically-cooled primordial gas in the early Universe are strong candidates for the seeds of supermassive BHs. DCBHs are thought to form in atomic cooling haloes in the…
We present cosmological hydrodynamical simulations including atomic and molecular non-equilibrium chemistry, multi-frequency radiative transfer (0.7-100 eV sampled over 150 frequency bins) and stellar population evolution to investigate the…
Direct collapse within dark matter (DM) halos is a promising path to form supermassive black hole (SMBH) seeds at high redshifts. The outer part of this collapse remains optically thin, and has been studied intensively using numerical…
A near pristine atomic cooling halo close to a star forming galaxy offers a natural pathway for forming massive direct collapse black hole (DCBH) seeds which could be the progenitors of the $z>6$ redshift quasars. The close proximity of the…
Direct-collapse black holes (DCBHs) are an important component of the massive black hole population of the early universe, and their formation and early mergers will be prominent in the data stream of the Laser Interferometer Space Antenna…
We have modeled direct collapse of a primordial gas within dark matter halos in the presence of radiative transfer, in high-resolution zoom-in simulations in a cosmological framework, down to the formation of the photosphere and the central…
We discuss the role of feedback via photoionization and Compton heating in the co-evolution of massive black holes at the center of spheroidal galaxies and their stellar and gaseous components. We first assess the energetics of the…
We study for the first time the environment of massive black hole (BH) seeds (~10^4-5 Msun) formed via the direct collapse of pristine gas clouds in massive haloes (>10^7 Msun) at z>6. Our model is based on the evolution of dark matter…
We provide a detailed analysis of quantum field theory around a collapsing shell and discuss several conceptual issues related to the emission of radiation flux and formation of black holes. Explicit calculations are performed using a model…
The nature of the seeds of high-redshift supermassive black holes (SMBHs) is a key question in cosmology. Direct collapse black holes (DCBH) that form in pristine, atomic-line cooling halos, illuminated by a Lyman-Werner (LW) UV flux…
The direct collapse black hole (DCBH) scenario describes the isothermal collapse of a pristine gas cloud directly into a massive, M_BH=10^4-10^6 M_sun black hole. In this paper we show that large HI column densities of primordial gas at…
We investigate the environment in which direct-collapse black holes may form by analysing a cosmological, hydrodynamical simulation that is part of the First Billion Years project. This simulation includes the most relevant physical…
The Direct Collapse Black Hole (DCBH) scenario provides a solution for forming the massive black holes powering bright quasars observed in the early Universe. A prerequisite for forming a DCBH is that the formation of (much less massive)…
We use semi-analytical models to study the effects of primordial black hole (PBH) accretion on the cosmic radiation background during the epoch of reionization ($z\gtrsim 6$). We consider PBHs floating in the intergalactic medium (IGM), and…