Related papers: Supercritical growth pathway to overmassive black …
The formation mechanism of supermassive black holes (SMBHs) in general, and of $\sim 10^9\,{\rm M}_{\odot}$ SMBHs observed as luminous quasars at redshifts $z> 6$ in particular, remains an open fundamental question. The presence of such…
The supermassive black holes (SMBHs) massive enough to power the bright redshift ~6 quasars observed in the Sloan Digital Sky Survey (SDSS) are thought to have assembled by mergers and/or gas accretion from less massive "seed" BHs. If the…
We employ cosmological hydrodynamical simulations to study the growth of massive black holes (BHs) at high redshifts subject to BH merger recoils from gravitational wave emission. We select the most massive dark matter halo at z=6 from the…
I review the current understanding of some key properties of the earliest growing supermassive black holes (SMBHs), as determined from the most up-to-date observations of z>=5 quasars. This includes their accretion rates and growth history,…
We discuss a model for the early assembly of supermassive black holes (SMBHs) at the center of galaxies that trace their hierarchical build-up far up in the dark halo `merger tree'. Motivated by the observations of luminous quasars around…
We study a model in which supermassive black holes (SMBHs) can grow by the combined action of gas accretion on heavy seeds and mergers of both heavy (m_s^h=10^5 Msol) and light (m_s^l = 10^2 Msol) seeds. The former result from the direct…
The properties of quasar-host galaxies might be determined by the growth and feedback of their supermassive (SMBH, $10^{8-10}$ M$_{\odot}$) black holes. We investigate such connection with a suite of cosmological simulations of massive…
In the local universe, the masses of Super-Massive Black-Holes (SMBH) appear to correlate with physical properties of their hosts, including the mass of the dark-matter halos. At higher redshifts, we observe the growth of SMBHs indirectly…
Supermassive black holes (SMBHs) with masses of $\sim 10^9 {\rm M_\odot}$ within the first billion year of the universe challenge our conventional understanding of black hole formation and growth. One pathway to these SMBHs proposes that…
Recent observations of quasars powered by supermassive black holes (SMBHs) out to z > 7 constrain both the initial seed masses and the growth of the most massive black holes (BHs) in the early universe. Here we elucidate the implications of…
Supermassive black holes (SMBHs) are observed in diverse galaxy populations across time yet a clear understanding of how they coevolve with their hosts has not been reached. Physically-motivated models of SMBH accretion and feedback vary…
The origin of supermassive black holes (SMBHs) remains a long-standing problem in astrophysics. Recent JWST observations reveal an unexpectedly abundant population of overmassive black holes at z>4-6, where the BH masses lie far above local…
The assembly of the first super massive black holes (SMBHs) at $z \gtrsim 6$ is still a subject of intense debate. If black holes (BHs) grow at their Eddington rate, they must start from $\gtrsim 10^4 \, M_\odot$ seeds formed by the direct…
Supermassive black holes (SMBHs) are thought to originate from early Universe seed black holes of mass $M_\mathrm{BH} \sim 10^2$-10$^5$ M$_{\odot}$ and grown through cosmic time. Such seeds could be powering the active galactic nuclei (AGN)…
High-redshift luminous quasars powered by accreting supermassive black holes (SMBHs) with mass $\gtrsim 10^9 M_\odot$ constrain their formation pathways. We investigate the formation of heavy seeds of SMBHs through gas collapse in the…
Supermassive black holes (SMBHs) are nowadays believed to reside in most local galaxies, and the available data show an empirical correlation between bulge luminosity - or stellar velocity dispersion - and black hole mass, suggesting a…
We report on the relation between the mass of supermassive black holes (SMBHs; M_BH) and that of hosting dark matter halos (M_h) for 49 z ~ 6 quasi-stellar objects (QSOs) with [CII]158um velocity-width measurements. Here, we estimate M_h…
Supermassive black holes (SMBHs) of 10^9-10^10 Msun were already in place ~13 Gyr ago, at z>6. Super-Eddington growth of low-mass BH seeds (~100 Msun) or less extreme accretion onto ~10^5 Msun seeds have been recently considered as the main…
The Sloan Digital Sky survey detected luminous quasars at very high redshift, z>6. Follow-up observations indicated that at least some of these quasars are powered by supermassive black holes (SMBHs) with masses in excess of billion solar…
Supermassive black holes (SMBHs) can grow through both accretion and mergers. It is still unclear how SMBHs evolve under these two channels from high redshifts to the SMBH population we observe in the local universe. Observations can…