Exploring Active Galactic Nuclei and Little Red Dots with the Obelisk simulation

Abstract

The James Webb Space telescope has discovered an abundant population of broad line emitters, typical signposts for Active Galactic Nuclei (AGN). Many of these sources have red colors and a compact appearance that has led to naming them `Little Red Dots'. In this paper we develop a detailed framework to estimate the photometry of AGN embedded in galaxies extracted from the \Obelisk{} cosmological simulation to understand the properties of color-selected Little Red Dots (cLRDs) in the context of the full AGN and massive black hole population. We find that using realistic spectral energy distributions (SEDs) and attenuation for AGN we can explain the shape of the cLRD SED as long as galaxies host a sufficiently luminous AGN that is not too much or too little attenuated. When attenuation is too low or too high, AGN do not enter the cLRD selection, because the AGN dominates over the host galaxy too much in blue filters, or it does not contribute to photometry anywhere, respectively. cLRDs are also characterized by high Eddington ratios, possibility super-Eddington, and/or high ratios between black hole and stellar mass.

Accepted for publication in A&A

References in corpus (50)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes
• Dancing in the dark: galactic properties trace spin swings along the cosmic web
• Intermediate-Mass Black Holes
• Intrinsic disc emission and the Soft X-ray Excess in AGN
• Reevaluating Old Stellar Populations
• Wet Disc Contraction to Galactic Blue Nuggets and Quenching to Red Nuggets
• Reverberation Measurements of the Inner Radius of the Dust Torus in Nearby Seyfert 1 Galaxies
• A unified model for tidal disruption events
• JADES. The diverse population of infant Black Holes at 4<z<11: merging, tiny, poor, but mighty
• RAMSES-RT: Radiation hydrodynamics in the cosmological context
• The Bolometric Quasar Luminosity Function at z = 0-7
• Super-Eddington Accretion Disks around Supermassive black Holes
• 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
• A scheme for radiation pressure and photon diffusion with the M1 closure in RAMSES-RT
• The Nuclear Reddening Curve for Active Galactic Nuclei and the Shape of the Infra-Red to X-Ray Spectral Energy Distribution
• High-redshift AGN in the Chandra Deep Fields: the obscured fraction and space density of the sub-$L_{\ast }$ population
• The effect of radiation pressure on dusty absorbing gas around AGN
• EIGER I. a large sample of [OIII]-emitting galaxies at $5.3<z<6.9$ and direct evidence for local reionization by galaxies
• The extinction law at high redshift and its implications
• The erratic dynamical life of black hole seeds in high-redshift galaxies
• Blowing cold flows away: the impact of early AGN activity on the formation of a brightest cluster galaxy progenitor
• Smoking Quasars: a New Source for Cosmic Dust
• The low-end of the black hole mass function at cosmic dawn
• Radiation pressure and absorption in AGN: results from a complete unbiased sample from Swift
• The Obelisk simulation: galaxies contribute more than AGN to HI reionization of protoclusters
• A dormant, overmassive black hole in the early Universe
• Mildly Super-Eddington Accretion Onto Slowly-Spinning Black Holes Explains the X-Ray Weakness of the Little Red Dots
• X-ray Properties of Intermediate-mass Black Holes in Active Galaxies. III. Spectral Energy Distribution and Possible Evidence for Intrinsically X-ray-weak AGNs
• RASCAS: RAdiation SCattering in Astrophysical Simulations
• QSO obscuration at high redshift ($z\gtrsim 7$): Predictions from the BlueTides simulation
• On how much X-ray and UV radiation processes are coupled in accretion disks: AGN case
• Modelling the spectral energy distribution of super-Eddington quasars
• Size matters: are we witnessing super-Eddington accretion in high-redshift black holes from JWST?
• High-redshift galaxies and black holes in the eyes of JWST: a population synthesis model from infrared to X-rays
• A physically-based model of the ionizing radiation from active galaxies for photoionization modeling
• Hyperaccreting black holes in galactic nuclei
• Chasing the observational signatures of seed black holes at z > 7: candidate observability
• Chasing the observational signatures of seed black holes at z > 7: candidate statistics
• Black hole obscuration and duty cycles mediated by AGN feedback in high redshift galaxies
• Can Cosmological Simulations Reproduce the Spectroscopically Confirmed Galaxies Seen at $z\ge 10$?
• Galaxies with grains: unraveling dust evolution and extinction curves with hydrodynamical simulations
• High-redshift quasars and their host galaxies II: multiphase gas and stellar kinematics
• Multimessenger study of merging massive black holes in the OBELISK simulation: gravitational waves, electromagnetic counterparts, and their link to galaxy and black hole populations
• AGN X-ray luminosity function and absorption function in the Early Universe ($3\le z\le 6$)
• Black hole mergers as tracers of spinning massive black hole and galaxy populations in the OBELISK simulation
• Resolving galactic-scale obscuration of X-ray AGN at $z\gtrsim 1$ with COSMOS-Web

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• The properties of primordially-seeded black holes and their hosts in the first billion years: implications for JWST
• Where Have All the Little Red Dots Gone? Supermassive Black Hole Binary Dynamics and its Impact on Galaxy Properties
• A weak Ly$\alpha$ halo for an extremely bright Little Red Dot: Indications of enshrouded SMBH growth
• Super-Eddington accretion in high-redshift quasar hosts: Black-hole driven outflows, galaxy quenching, and the nature of little red dots
• A novel sub-grid model for super-Eddington accretion of spinning black holes in galaxy-scale simulations