EVIDENCE FOR WIDESPREAD ACTIVE GALACTIC NUCLEUS ACTIVITY AMONG MASSIVE QUIESCENT GALAXIES AT z {approx} 2
Abstract
We quantify the presence of active galactic nuclei (AGNs) in a mass-complete (M {sub *} > 5 Multiplication-Sign 10{sup 10} M {sub Sun }) sample of 123 star-forming and quiescent galaxies at 1.5 {<=} z {<=} 2.5, using X-ray data from the 4 Ms Chandra Deep Field-South (CDF-S) survey. 41% {+-} 7% of the galaxies are detected directly in X-rays, 22% {+-} 5% with rest-frame 0.5-8 keV luminosities consistent with hosting luminous AGNs (L {sub 0.5-8keV} > 3 Multiplication-Sign 10{sup 42} erg s{sup -1}). The latter fraction is similar for star-forming and quiescent galaxies, and does not depend on galaxy stellar mass, suggesting that perhaps luminous AGNs are triggered by external effects such as mergers. We detect significant mean X-ray signals in stacked images for both the individually non-detected star-forming and quiescent galaxies, with spectra consistent with star formation only and/or a low-luminosity AGN in both cases. Comparing star formation rates inferred from the 2-10 keV luminosities to those from rest-frame IR+UV emission, we find evidence for an X-ray excess indicative of low-luminosity AGNs. Among the quiescent galaxies, the excess suggests that as many as 70%-100% of these contain low- or high-luminosity AGNs, while the corresponding fraction is lower amongmore »
- Authors:
- Publication Date:
- OSTI Identifier:
- 22167083
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal
- Additional Journal Information:
- Journal Volume: 764; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; EMISSION; GALACTIC EVOLUTION; GALAXY NUCLEI; IMAGES; KEV RANGE 01-10; LUMINOSITY; MASS; RED SHIFT; SPECTRA; STARS; X RADIATION; X-RAY GALAXIES
Citation Formats
Olsen, Karen P., Rasmussen, Jesper, Toft, Sune, and Zirm, Andrew W., E-mail: karen@dark-cosmology.dk. EVIDENCE FOR WIDESPREAD ACTIVE GALACTIC NUCLEUS ACTIVITY AMONG MASSIVE QUIESCENT GALAXIES AT z {approx} 2. United States: N. p., 2013.
Web. doi:10.1088/0004-637X/764/1/4.
Olsen, Karen P., Rasmussen, Jesper, Toft, Sune, & Zirm, Andrew W., E-mail: karen@dark-cosmology.dk. EVIDENCE FOR WIDESPREAD ACTIVE GALACTIC NUCLEUS ACTIVITY AMONG MASSIVE QUIESCENT GALAXIES AT z {approx} 2. United States. https://doi.org/10.1088/0004-637X/764/1/4
Olsen, Karen P., Rasmussen, Jesper, Toft, Sune, and Zirm, Andrew W., E-mail: karen@dark-cosmology.dk. 2013.
"EVIDENCE FOR WIDESPREAD ACTIVE GALACTIC NUCLEUS ACTIVITY AMONG MASSIVE QUIESCENT GALAXIES AT z {approx} 2". United States. https://doi.org/10.1088/0004-637X/764/1/4.
@article{osti_22167083,
title = {EVIDENCE FOR WIDESPREAD ACTIVE GALACTIC NUCLEUS ACTIVITY AMONG MASSIVE QUIESCENT GALAXIES AT z {approx} 2},
author = {Olsen, Karen P. and Rasmussen, Jesper and Toft, Sune and Zirm, Andrew W., E-mail: karen@dark-cosmology.dk},
abstractNote = {We quantify the presence of active galactic nuclei (AGNs) in a mass-complete (M {sub *} > 5 Multiplication-Sign 10{sup 10} M {sub Sun }) sample of 123 star-forming and quiescent galaxies at 1.5 {<=} z {<=} 2.5, using X-ray data from the 4 Ms Chandra Deep Field-South (CDF-S) survey. 41% {+-} 7% of the galaxies are detected directly in X-rays, 22% {+-} 5% with rest-frame 0.5-8 keV luminosities consistent with hosting luminous AGNs (L {sub 0.5-8keV} > 3 Multiplication-Sign 10{sup 42} erg s{sup -1}). The latter fraction is similar for star-forming and quiescent galaxies, and does not depend on galaxy stellar mass, suggesting that perhaps luminous AGNs are triggered by external effects such as mergers. We detect significant mean X-ray signals in stacked images for both the individually non-detected star-forming and quiescent galaxies, with spectra consistent with star formation only and/or a low-luminosity AGN in both cases. Comparing star formation rates inferred from the 2-10 keV luminosities to those from rest-frame IR+UV emission, we find evidence for an X-ray excess indicative of low-luminosity AGNs. Among the quiescent galaxies, the excess suggests that as many as 70%-100% of these contain low- or high-luminosity AGNs, while the corresponding fraction is lower among star-forming galaxies (43%-65%). Our discovery of the ubiquity of AGNs in massive, quiescent z {approx} 2 galaxies provides observational support for the importance of AGNs in impeding star formation during galaxy evolution.},
doi = {10.1088/0004-637X/764/1/4},
url = {https://www.osti.gov/biblio/22167083},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 764,
place = {United States},
year = {Sun Feb 10 00:00:00 EST 2013},
month = {Sun Feb 10 00:00:00 EST 2013}
}