_version_ 1866929618192171008
author Tripodi, Roberta
Martis, Nicholas
Markov, Vladan
Bradač, Maruša
Di Mascia, Fabio
Cammelli, Vieri
D'Eugenio, Francesco
Willott, Chris
Curti, Mirko
Bhatt, Maulik
Gallerani, Simona
Rihtaršič, Gregor
Singh, Jasbir
Gaspar, Gaia
Harshan, Anishya
Judež, Jon
Merida, Rosa M.
Desprez, Guillaume
Sawicki, Marcin
Goovaerts, Ilias
Muzzin, Adam
Noirot, Gaël
Sarrouh, Ghassan T. E.
Abraham, Roberto
Asada, Yoshihisa
Brammer, Gabriel
Carpenter, Vicente Estrada
Felicioni, Giordano
Fujimoto, Seiji
Iyer, Kartheik
Mowla, Lamiya
Strait, Victoria
author_facet Tripodi, Roberta
Martis, Nicholas
Markov, Vladan
Bradač, Maruša
Di Mascia, Fabio
Cammelli, Vieri
D'Eugenio, Francesco
Willott, Chris
Curti, Mirko
Bhatt, Maulik
Gallerani, Simona
Rihtaršič, Gregor
Singh, Jasbir
Gaspar, Gaia
Harshan, Anishya
Judež, Jon
Merida, Rosa M.
Desprez, Guillaume
Sawicki, Marcin
Goovaerts, Ilias
Muzzin, Adam
Noirot, Gaël
Sarrouh, Ghassan T. E.
Abraham, Roberto
Asada, Yoshihisa
Brammer, Gabriel
Carpenter, Vicente Estrada
Felicioni, Giordano
Fujimoto, Seiji
Iyer, Kartheik
Mowla, Lamiya
Strait, Victoria
contents The James Webb Space Telescope (JWST) has recently discovered a new population of objects at high redshift referred to as `Little Red Dots' (LRDs). Their nature currently remains elusive, despite their surprisingly high inferred number densities. This emerging population of red point-like sources is reshaping our view of the early Universe and may shed light on the formation of high-redshift supermassive black holes. Here we present a spectroscopically confirmed LRD CANUCS-LRD-z8.6 at $z_{\rm spec}=8.6319\pm 0.0005$ hosting an Active Galactic Nucleus (AGN), using JWST data. This source shows the typical spectral shape of an LRD (blue UV and red optical continuum, unresolved in JWST imaging), along with broad H$β$ line emission, detection of high-ionization emission lines (CIV, NIV]) and very high electron temperature indicative of the presence of AGN. This is also combined with a very low metallicity ($Z<0.1 Z_\odot$). The presence of all these diverse features in one source makes CANUCS-LRD-z8.6 unique. We show that the inferred black hole mass of CANUCS-LRD-z8.6 ($M_{\rm BH}=1.0^{+0.6}_{-0.4}\times 10^{8}\rm ~M_\odot$) strongly challenges current standard theoretical models and simulations of black hole formation, and forces us to adopt `ad hoc' prescriptions. Indeed if massive seeds, or light seeds with super-Eddington accretion, are considered, the observed BH mass of CANUCS-LRD-z8.6 at $z=8.6$ can be reproduced. Moreover, the black hole is over-massive compared to its host, relative to the local $M_{\rm BH}-M_*$ relations, pointing towards an earlier and faster evolution of the black hole compared to its host galaxy.
format Preprint
id arxiv_https___arxiv_org_abs_2412_04983
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Red, hot, and very metal poor: extreme properties of a massive accreting black hole in the first 500 Myr
Tripodi, Roberta
Martis, Nicholas
Markov, Vladan
Bradač, Maruša
Di Mascia, Fabio
Cammelli, Vieri
D'Eugenio, Francesco
Willott, Chris
Curti, Mirko
Bhatt, Maulik
Gallerani, Simona
Rihtaršič, Gregor
Singh, Jasbir
Gaspar, Gaia
Harshan, Anishya
Judež, Jon
Merida, Rosa M.
Desprez, Guillaume
Sawicki, Marcin
Goovaerts, Ilias
Muzzin, Adam
Noirot, Gaël
Sarrouh, Ghassan T. E.
Abraham, Roberto
Asada, Yoshihisa
Brammer, Gabriel
Carpenter, Vicente Estrada
Felicioni, Giordano
Fujimoto, Seiji
Iyer, Kartheik
Mowla, Lamiya
Strait, Victoria
Astrophysics of Galaxies
The James Webb Space Telescope (JWST) has recently discovered a new population of objects at high redshift referred to as `Little Red Dots' (LRDs). Their nature currently remains elusive, despite their surprisingly high inferred number densities. This emerging population of red point-like sources is reshaping our view of the early Universe and may shed light on the formation of high-redshift supermassive black holes. Here we present a spectroscopically confirmed LRD CANUCS-LRD-z8.6 at $z_{\rm spec}=8.6319\pm 0.0005$ hosting an Active Galactic Nucleus (AGN), using JWST data. This source shows the typical spectral shape of an LRD (blue UV and red optical continuum, unresolved in JWST imaging), along with broad H$β$ line emission, detection of high-ionization emission lines (CIV, NIV]) and very high electron temperature indicative of the presence of AGN. This is also combined with a very low metallicity ($Z<0.1 Z_\odot$). The presence of all these diverse features in one source makes CANUCS-LRD-z8.6 unique. We show that the inferred black hole mass of CANUCS-LRD-z8.6 ($M_{\rm BH}=1.0^{+0.6}_{-0.4}\times 10^{8}\rm ~M_\odot$) strongly challenges current standard theoretical models and simulations of black hole formation, and forces us to adopt `ad hoc' prescriptions. Indeed if massive seeds, or light seeds with super-Eddington accretion, are considered, the observed BH mass of CANUCS-LRD-z8.6 at $z=8.6$ can be reproduced. Moreover, the black hole is over-massive compared to its host, relative to the local $M_{\rm BH}-M_*$ relations, pointing towards an earlier and faster evolution of the black hole compared to its host galaxy.
title Red, hot, and very metal poor: extreme properties of a massive accreting black hole in the first 500 Myr
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2412.04983