A Census of Photometrically Selected Little Red Dots at 4 < z < 9 in JWST Blank Fields

Vasily Kokorev, Karina I. Caputi, Jenny E. Greene, Pratika Dayal, Maxime Trebitsch, Sam E. Cutler, Seiji Fujimoto, Ivo Labbé, Tim B. Miller, Edoardo Iani, Rafael Navarro-Carrera, Pierluigi Rinaldi

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Observations with the James Webb Space Telescope (JWST) have uncovered numerous faint active galactic nuclei (AGN) at z ∼ 5 and beyond. These objects are key to our understanding of the formation of supermassive black holes (SMBHs), their coevolution with host galaxies, as well as the role of AGN in cosmic reionization. Using photometric colors and size measurements, we perform a search for compact red objects in an array of blank deep JWST/NIRCam fields totaling ∼640 arcmin2. Our careful selection yields 260 reddened AGN candidates at 4 < z phot < 9, dominated by a point-source-like central component (〈reff〉 < 130 pc) and displaying a dichotomy in their rest-frame colors (blue UV and red optical slopes). Quasar model fitting reveals our objects to be moderately dust-extincted (A V ∼ 1.6), which is reflected in their inferred bolometric luminosities of L bol = 1044-47 erg s−1 and fainter UV magnitudes M UV ≃ −17 to −22. Thanks to the large areas explored, we extend the existing dusty AGN luminosity functions to both fainter and brighter magnitudes, estimating their number densities to be ×100 higher than for UV-selected quasars of similar magnitudes. At the same time, they constitute only a small fraction of all UV-selected galaxies at similar redshifts, but this percentage rises to ∼10% for M UV ∼ − 22 at z ∼ 7. Finally, assuming a conservative case of accretion at the Eddington rate, we place a lower limit on the SMBH mass function at z ∼ 5, finding it to be consistent with both theory and previous JWST observations.

Original languageEnglish (US)
Article number38
JournalAstrophysical Journal
Volume968
Issue number1
DOIs
StatePublished - Jun 1 2024

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'A Census of Photometrically Selected Little Red Dots at 4 < z < 9 in JWST Blank Fields'. Together they form a unique fingerprint.

Cite this