EPOCHS VII: discovery of high-redshift (6.5 < z < 12) AGN candidates in JWST ERO and PEARLS data

Abstract

We present an analysis of a sample of robust high-redshift galaxies selected from the ‘blank’ fields of the Prime Extragalactic Areas for Reionization Science (PEARLS) survey and Early Release Observations (ERO) data from JWST with the aim of selecting candidate high-redshift active galactic nuclei (AGN). Sources were identified from this parent sample using a threefold selection procedure, which includes spectral energy distribution (SED) fitting to identify sources that are best fitted by AGN SED templates, a further selection based on the relative performance of AGN and non-AGN models, and finally morphological fitting to identify compact sources of emission, resulting in a purity-oriented procedure. Using this procedure, we identify a sample of nine AGN candidates at 6.5 < z < 12, from which we constrain their physical properties as well as measure a lower bound on the AGN fraction in this redshift range of 5 ± 1%. As this is an extreme lower limit due to our focus on purity and our SEDs being calibrated for unobscured Type 1 AGN, this demonstrates that AGN are perhaps quite common at this early epoch. The rest-frame UV colors of our candidate objects suggest that these systems are potentially candidate obese black hole galaxies (OBG). We also investigate Chandra and VLA maps of these areas from which we calculate detection limits. Of note is a z = 11.9 candidate source exhibiting an abrupt morphological shift in the reddest band as compared to bluer bands, indicating a potential merger or an unusually strong outflow.

First Detection of an Overmassive Black Hole Galaxy UHZ1: Evidence for Heavy Black Hole Seed Formation from Direct Collapse

“…Data flowing currently from the JWST are rapidly reshaping our understanding of early galaxy formation with the reported detection of large numbers of faint, distant galaxies at z > 9 (Castellano et al 2022(Castellano et al , 2023Harikane et al 2023;Naidu et al 2022;Adams et al 2023;Atek et al 2023aAtek et al , 2023bLeung et al 2023), many of which may harbor central BHs (Bogdan et al 2023;Juodžbalis et al 2023;Larson et al 2023;Maiolino et al 2023).…”

Little Red Dots or Brown Dwarfs? NIRSpec Discovery of Three Distant Brown Dwarfs Masquerading as NIRCam-selected Highly Reddened Active Galactic Nuclei

“…JWST photometry has revealed a population of red and extremely compact sources, the little red dots, representing faint and/or highly reddened active galactic nuclei (AGNs) at z > 3 (Barro et al 2023;Bogdan et al 2023;Endsley et al 2023;Furtak et al 2023a;Juodžbalis et al 2023;Labbe et al 2023;Onoue et al 2023;Yang et al 2023). The nature of some of these sources is being confirmed through NIRCam wide field slitless spectroscopy (Matthee et al 2023) and NIRSpec follow-up campaigns (Barro et al 2023;Carnall et al 2023;Furtak et al 2023b;Harikane et al 2023;Kocevski et al 2023;Larson et al 2023;Maiolino et al 2023aMaiolino et al , 2023bÜbler et al 2023).…”

Galaxy Quenching at the High Redshift Frontier: A Fundamental Test of Cosmological Models in the Early Universe with JWST-CEERS

“…We utilize novel data from the public JWST-CEERS photometric survey (Finkelstein et al 2023b;Kartaltepe et al 2023;Kocevski et al 2023) to probe galaxy quenching at intermediate (z = 0.5-2), high (z = 2-4), and ultrahigh (z = 4-8) redshifts. Our analysis of this data represents the first test of quenching mechanisms in the very early Universe, where we are just now discovering that AGN are likely very common (e.g., Juodžbalis et al 2023;Marshall et al 2023;Ubler et al 2023). Furthermore, the JWST data, in combination with lower-z surveys (see below), enable a unified analysis of star formation quenching in galaxies across essentially all of cosmic time.…”