_version_ 1866909459470614528
author Kocevski, Dale D.
Finkelstein, Steven L.
Barro, Guillermo
Taylor, Anthony J.
Calabrò, Antonello
Laloux, Brivael
Buchner, Johannes
Trump, Jonathan R.
Leung, Gene C. K.
Yang, Guang
Dickinson, Mark
Pérez-González, Pablo G.
Pacucci, Fabio
Inayoshi, Kohei
Somerville, Rachel S.
McGrath, Elizabeth J.
Akins, Hollis B.
Bagley, Micaela B.
Bisigello, Laura
Bowler, Rebecca A. A.
Carnall, Adam
Casey, Caitlin M.
Cheng, Yingjie
Cleri, Nikko J.
Costantin, Luca
Cullen, Fergus
Davis, Kelcey
Donnan, Callum T.
Dunlop, James S.
Ellis, Richard S.
Ferguson, Henry C.
Fujimoto, Seiji
Fontana, Adriano
Giavalisco, Mauro
Grazian, Andrea
Grogin, Norman A.
Hathi, Nimish P.
Hirschmann, Michaela
Huertas-Company, Marc
Holwerda, Benne W.
Illingworth, Garth
Juneau, Stéphanie
Kartaltepe, Jeyhan S.
Koekemoer, Anton M.
Li, Wenxiu
Lucas, Ray A.
Magee, Dan
Mason, Charlotte
McLeod, Derek J.
McLure, Ross J.
Napolitano, Lorenzo
Papovich, Casey
Pirzkal, Nor
Rodighiero, Giulia
Santini, Paola
Wilkins, Stephen M.
Yung, L. Y. Aaron
author_facet Kocevski, Dale D.
Finkelstein, Steven L.
Barro, Guillermo
Taylor, Anthony J.
Calabrò, Antonello
Laloux, Brivael
Buchner, Johannes
Trump, Jonathan R.
Leung, Gene C. K.
Yang, Guang
Dickinson, Mark
Pérez-González, Pablo G.
Pacucci, Fabio
Inayoshi, Kohei
Somerville, Rachel S.
McGrath, Elizabeth J.
Akins, Hollis B.
Bagley, Micaela B.
Bisigello, Laura
Bowler, Rebecca A. A.
Carnall, Adam
Casey, Caitlin M.
Cheng, Yingjie
Cleri, Nikko J.
Costantin, Luca
Cullen, Fergus
Davis, Kelcey
Donnan, Callum T.
Dunlop, James S.
Ellis, Richard S.
Ferguson, Henry C.
Fujimoto, Seiji
Fontana, Adriano
Giavalisco, Mauro
Grazian, Andrea
Grogin, Norman A.
Hathi, Nimish P.
Hirschmann, Michaela
Huertas-Company, Marc
Holwerda, Benne W.
Illingworth, Garth
Juneau, Stéphanie
Kartaltepe, Jeyhan S.
Koekemoer, Anton M.
Li, Wenxiu
Lucas, Ray A.
Magee, Dan
Mason, Charlotte
McLeod, Derek J.
McLure, Ross J.
Napolitano, Lorenzo
Papovich, Casey
Pirzkal, Nor
Rodighiero, Giulia
Santini, Paola
Wilkins, Stephen M.
Yung, L. Y. Aaron
contents We present a sample of 341 "little red dots" (LRDs) spanning the redshift range $z\sim2-11$ using data from the CEERS, PRIMER, JADES, UNCOVER and NGDEEP surveys. Unlike past use of color indices to identify LRDs, we employ continuum slope fitting using shifting bandpasses to sample the same rest-frame emission blueward and redward of the Balmer break. This enables the detection of LRDs over a wider redshift range and with less contamination from galaxies with strong breaks that otherwise lack a rising red continuum. The redshift distribution of our sample increases at $z<8$ and then undergoes a rapid decline at $z\sim4.5$, which may tie the emergence of these sources to the inside-out growth that galaxies experience during this epoch. We find that LRDs are $\sim1$ dex more numerous than X-ray and UV selected AGN at z~5-7. Within our sample, we have identified the first two X-ray detected LRDs. An X-ray spectral analysis confirms that these AGN are moderately obscured with $\log\,(N_{\rm H}/{\rm cm}^{2}$) of $23.3^{+0.4}_{-1.3}$ and $22.72^{+0.13}_{-0.16}$. Our analysis reveals that reddened AGN emission dominates their rest-optical light, while the rest-UV originates from their host galaxies. We also present NIRSpec observations from the RUBIES survey of 17 LRDs that show broad emission lines consistent with AGN activity. The confirmed AGN fraction of our sample is 71\% for sources with F444W<26.5. In addition, we find three LRDs with blue-shifted Balmer absorption features in their spectra, suggesting an outflow of high-density, low-ionization gas from near the central engine of these faint, red AGN.
format Preprint
id arxiv_https___arxiv_org_abs_2404_03576
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The Rise of Faint, Red AGN at $z>4$: A Sample of Little Red Dots in the JWST Extragalactic Legacy Fields
Kocevski, Dale D.
Finkelstein, Steven L.
Barro, Guillermo
Taylor, Anthony J.
Calabrò, Antonello
Laloux, Brivael
Buchner, Johannes
Trump, Jonathan R.
Leung, Gene C. K.
Yang, Guang
Dickinson, Mark
Pérez-González, Pablo G.
Pacucci, Fabio
Inayoshi, Kohei
Somerville, Rachel S.
McGrath, Elizabeth J.
Akins, Hollis B.
Bagley, Micaela B.
Bisigello, Laura
Bowler, Rebecca A. A.
Carnall, Adam
Casey, Caitlin M.
Cheng, Yingjie
Cleri, Nikko J.
Costantin, Luca
Cullen, Fergus
Davis, Kelcey
Donnan, Callum T.
Dunlop, James S.
Ellis, Richard S.
Ferguson, Henry C.
Fujimoto, Seiji
Fontana, Adriano
Giavalisco, Mauro
Grazian, Andrea
Grogin, Norman A.
Hathi, Nimish P.
Hirschmann, Michaela
Huertas-Company, Marc
Holwerda, Benne W.
Illingworth, Garth
Juneau, Stéphanie
Kartaltepe, Jeyhan S.
Koekemoer, Anton M.
Li, Wenxiu
Lucas, Ray A.
Magee, Dan
Mason, Charlotte
McLeod, Derek J.
McLure, Ross J.
Napolitano, Lorenzo
Papovich, Casey
Pirzkal, Nor
Rodighiero, Giulia
Santini, Paola
Wilkins, Stephen M.
Yung, L. Y. Aaron
Astrophysics of Galaxies
We present a sample of 341 "little red dots" (LRDs) spanning the redshift range $z\sim2-11$ using data from the CEERS, PRIMER, JADES, UNCOVER and NGDEEP surveys. Unlike past use of color indices to identify LRDs, we employ continuum slope fitting using shifting bandpasses to sample the same rest-frame emission blueward and redward of the Balmer break. This enables the detection of LRDs over a wider redshift range and with less contamination from galaxies with strong breaks that otherwise lack a rising red continuum. The redshift distribution of our sample increases at $z<8$ and then undergoes a rapid decline at $z\sim4.5$, which may tie the emergence of these sources to the inside-out growth that galaxies experience during this epoch. We find that LRDs are $\sim1$ dex more numerous than X-ray and UV selected AGN at z~5-7. Within our sample, we have identified the first two X-ray detected LRDs. An X-ray spectral analysis confirms that these AGN are moderately obscured with $\log\,(N_{\rm H}/{\rm cm}^{2}$) of $23.3^{+0.4}_{-1.3}$ and $22.72^{+0.13}_{-0.16}$. Our analysis reveals that reddened AGN emission dominates their rest-optical light, while the rest-UV originates from their host galaxies. We also present NIRSpec observations from the RUBIES survey of 17 LRDs that show broad emission lines consistent with AGN activity. The confirmed AGN fraction of our sample is 71\% for sources with F444W<26.5. In addition, we find three LRDs with blue-shifted Balmer absorption features in their spectra, suggesting an outflow of high-density, low-ionization gas from near the central engine of these faint, red AGN.
title The Rise of Faint, Red AGN at $z>4$: A Sample of Little Red Dots in the JWST Extragalactic Legacy Fields
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2404.03576