_version_ 1866910123717296128
author Maiolino, Roberto
Uebler, Hannah
D'Eugenio, Francesco
Scholtz, Jan
Juodzbalis, Ignas
Ji, Xihan
Perna, Michele
Bromm, Volker
Dayal, Pratika
Koudmani, Sophie
Liu, Boyuan
Schneider, Raffaella
Sijacki, Debora
Valiante, Rosa
Trinca, Alessandro
Zhang, Saiyang
Volonteri, Marta
Inayoshi, Kohei
Carniani, Stefano
Nakajima, Kimihiko
Isobe, Yuki
Witstok, Joris
Jones, Gareth C.
Tacchella, Sandro
Arribas, Santiago
Bunker, Andrew
Cataldi, Elisa
Charlot, Stephane
Cresci, Giovanni
Curti, Mirko
Fabian, Andrew C.
Katz, Harley
Kumari, Nimisha
Laporte, Nicolas
Mazzolari, Giovanni
Robertson, Brant
Sun, Fengwu
Del Pino, Bruno Rodriguez
Venturi, Giacomo
author_facet Maiolino, Roberto
Uebler, Hannah
D'Eugenio, Francesco
Scholtz, Jan
Juodzbalis, Ignas
Ji, Xihan
Perna, Michele
Bromm, Volker
Dayal, Pratika
Koudmani, Sophie
Liu, Boyuan
Schneider, Raffaella
Sijacki, Debora
Valiante, Rosa
Trinca, Alessandro
Zhang, Saiyang
Volonteri, Marta
Inayoshi, Kohei
Carniani, Stefano
Nakajima, Kimihiko
Isobe, Yuki
Witstok, Joris
Jones, Gareth C.
Tacchella, Sandro
Arribas, Santiago
Bunker, Andrew
Cataldi, Elisa
Charlot, Stephane
Cresci, Giovanni
Curti, Mirko
Fabian, Andrew C.
Katz, Harley
Kumari, Nimisha
Laporte, Nicolas
Mazzolari, Giovanni
Robertson, Brant
Sun, Fengwu
Del Pino, Bruno Rodriguez
Venturi, Giacomo
contents The recent discovery of a large number of massive black holes within the first two billion years after the Big Bang, as well as their peculiar properties, have been largely unexpected based on the extrapolation of the properties of luminous quasars. These findings have prompted the development of several theoretical models for the early formation and growth of black holes, which are, however, difficult to differentiate. We report the metallicity measurement around a gravitationally lensed massive black hole at redshift 7.04 (classified as a Little Red Dot), hosted in a galaxy with very low dynamical mass. The weakness of the [OIII]5007 emission line relative to the narrow H$β$ emission indicates extremely low metallicity, about $4\times 10^{-3}$ solar, and even more metal poor in the surrounding few 100 pc. We argue that such properties cannot be uncommon among accreting black holes around this early cosmic epoch. Explaining such a low chemical enrichment in a system that has developed a massive black hole is challenging for most theories. Models assuming heavy black hole seeds (such as Direct Collapse Black Holes) or super-Eddington accretion scenarios struggle to explain the observations, although they can potentially reproduce the observed properties in some cases. Models invoking "primordial black holes" (i.e. putative black holes formed shortly after the Big Bang) may potentially explain the low chemical enrichment associated with this black hole, although this class of models also requires further developments for proper testing.
format Preprint
id arxiv_https___arxiv_org_abs_2505_22567
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A black hole in a near-pristine galaxy 700 million years after the Big Bang
Maiolino, Roberto
Uebler, Hannah
D'Eugenio, Francesco
Scholtz, Jan
Juodzbalis, Ignas
Ji, Xihan
Perna, Michele
Bromm, Volker
Dayal, Pratika
Koudmani, Sophie
Liu, Boyuan
Schneider, Raffaella
Sijacki, Debora
Valiante, Rosa
Trinca, Alessandro
Zhang, Saiyang
Volonteri, Marta
Inayoshi, Kohei
Carniani, Stefano
Nakajima, Kimihiko
Isobe, Yuki
Witstok, Joris
Jones, Gareth C.
Tacchella, Sandro
Arribas, Santiago
Bunker, Andrew
Cataldi, Elisa
Charlot, Stephane
Cresci, Giovanni
Curti, Mirko
Fabian, Andrew C.
Katz, Harley
Kumari, Nimisha
Laporte, Nicolas
Mazzolari, Giovanni
Robertson, Brant
Sun, Fengwu
Del Pino, Bruno Rodriguez
Venturi, Giacomo
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
The recent discovery of a large number of massive black holes within the first two billion years after the Big Bang, as well as their peculiar properties, have been largely unexpected based on the extrapolation of the properties of luminous quasars. These findings have prompted the development of several theoretical models for the early formation and growth of black holes, which are, however, difficult to differentiate. We report the metallicity measurement around a gravitationally lensed massive black hole at redshift 7.04 (classified as a Little Red Dot), hosted in a galaxy with very low dynamical mass. The weakness of the [OIII]5007 emission line relative to the narrow H$β$ emission indicates extremely low metallicity, about $4\times 10^{-3}$ solar, and even more metal poor in the surrounding few 100 pc. We argue that such properties cannot be uncommon among accreting black holes around this early cosmic epoch. Explaining such a low chemical enrichment in a system that has developed a massive black hole is challenging for most theories. Models assuming heavy black hole seeds (such as Direct Collapse Black Holes) or super-Eddington accretion scenarios struggle to explain the observations, although they can potentially reproduce the observed properties in some cases. Models invoking "primordial black holes" (i.e. putative black holes formed shortly after the Big Bang) may potentially explain the low chemical enrichment associated with this black hole, although this class of models also requires further developments for proper testing.
title A black hole in a near-pristine galaxy 700 million years after the Big Bang
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2505.22567