How long do high-redshift massive black hole seeds remain outliers in black hole vs. host galaxy relations?

Abstract

The existence of $10^9{\mathrm{M}}_{\odot }$ supermassive black holes (SMBHs) within the first billion years of the universe remains a puzzle in our conventional understanding of black hole formation and growth. Several suggested formation pathways for these SMBHs lead to a heavy seed, with an initial black hole mass of $10^4-10^6{\mathrm{M}}_{\odot }$. This can lead to an overly massive BH galaxy (OMBG), whose nuclear black hole's mass is comparable to or even greater than the surrounding stellar mass: the black hole to stellar mass ratio is $M_{\mathrm{bh}}/M_{\ast }\gg 10^{-3}$, well in excess of the typical values at lower redshift. We investigate how long these newborn BHs remain outliers in the $M_{\mathrm{bh}}-M_{\ast }$ relation, by exploring the subsequent evolution of two OMBGs previously identified in the \texttt{Renaissance} simulations. We find that both OMBGs have $M_{\mathrm{bh}}/M_{\ast }>1$ during their entire life, from their birth at $z\approx 15$ until they merge with much more massive haloes at $z\approx 8$. We find that the OMBGs are spatially resolvable from their more massive, $10^{11}{\mathrm{M}}_{\odot }$, neighboring haloes until their mergers are complete at $z\approx 8$. This affords a window for future observations with {\it JWST} and sensitive X-ray telescopes to diagnose the heavy-seed scenario, by detecting similar OMBGs and establishing their uniquely high black hole-to-stellar mass ratio.

15 pages, 10 figures. Accepted in MNRAS

References in corpus (29)

• Formation of Supermassive Black Holes by Direct Collapse in Pregalactic Halos
• A Global Three Dimensional Radiation Magneto-hydrodynamic Simulation of Super-Eddington Accretion Disks
• Protostar Formation in the Early Universe
• The Mass Spectrum of the First Stars
• Accretion onto the First Stellar Mass Black Holes
• The origins of massive black holes
• Super-Critical Growth of Massive Black Holes from Stellar-Mass Seeds
• Formation of massive black holes in rapidly growing pre-galactic gas clouds
• Global simulations of axisymmetric radiative black hole accretion disks in general relativity with a sub-grid magnetic dynamo
• Rapid growth of seed black holes in the early universe by supra-exponential accretion
• The Evolution of Supermassive Population III Stars
• Initial mass function of intermediate mass black hole seeds
• The critical radiation intensity for direct collapse black hole formation: dependence on the radiation spectral shape
• Accretion onto Intermediate-Mass Black Holes in Dense Protogalactic Clouds
• The erratic dynamical life of black hole seeds in high-redshift galaxies
• Supersonic Gas Streams Enhance the Formation of Massive Black Holes in the Early Universe
• Diagnostics for PopIII galaxies and Direct Collapse Black Holes in the early universe
• Formation of massive protostars in atomic cooling haloes
• The Final Fates of Accreting Supermassive Stars
• Formation of an embryonic supermassive star in the first galaxy
• The Preferential Tidal Stripping of Dark Matter versus Stars in Galaxies
• Conditions for Optimal Growth of Black Hole Seeds
• Co-evolution of massive black holes and their host galaxies at high redshift: discrepancies from six cosmological simulations and the key role of JWST
• Forming massive seed black holes in high-redshift quasar host progenitors
• Beyond Jcrit: a critical curve for suppression of H2-cooling in protogalaxies
• Origin of supermassive black holes in massive metal-poor protoclusters
• The Age of Discovery with the James Webb: Excavating the Spectral Signatures of the First Massive Black Holes
• Evolution of high-redshift quasar hosts and promotion of massive black hole seed formation
• Massive Star Formation in Metal-Enriched Haloes at High Redshift

Cited by in corpus (9)

• JWST CEERS & JADES Active Galaxies at z = 4-7 Violate the Local $M_{\bullet }-M_{\star }$ Relation at $>3\sigma$: Implications for Low-Mass Black Holes and Seeding Models
• Mildly Super-Eddington Accretion Onto Slowly-Spinning Black Holes Explains the X-Ray Weakness of the Little Red Dots
• Little Red Dots: Rapidly Growing Black Holes Reddened by Extended Dusty Flows
• The Redshift Evolution of the $M_{\bullet }-M_{\star }$ Relation for JWST's Supermassive Black Holes at $z>4$
• Overmassive black holes at cosmic noon: linking the local and the high-redshift Universe
• Exploring the AGN Fraction of a Sample of JWST's Little Red Dots at $5<z<8$: Overmassive Black Holes Are Strongly Favored
• Rapid formation of a very massive star >50000 $M_{\odot }$ and subsequently an IMBH from runaway collisions. Direct N-body and Monte Carlo simulations of dense star clusters
• High-redshift AGN population in radiation-hydrodynamics simulations
• No Significant Redshift Evolution in the Intrinsic Scatter of the $M_{\bullet }$-$M_{\star }$ Relation for Overmassive Black Holes