COSMIC EVOLUTION OF RADIO SELECTED ACTIVE GALACTIC NUCLEI IN THE COSMOS FIELD

Journal Article · Fri May 01 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/696/1/24; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21296226

Smolcic, V; Salvato, M; Scoville, N ^[1]; Zamorani, G; Bardelli, S; Ciliegi, P ^[2]; Schinnerer, E ^[3]; Bondi, M ^[4]; BIrzan, L ^[5]; Carilli, C L ^[6]; Elvis, M ^[7]; Impey, C D; Trump, J R ^[8]; Koekemoer, A M ^[9]; Merloni, A ^[10]; Scodeggio, M ^[11]; Paglione, T

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1. California Institute of Technology, MC 105-24, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
2. INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna (Italy)
3. Max Planck Institut fuer Astronomie, Koenigstuhl 17, Heidelberg, D-69117 (Germany)
4. INAF-Istituto di Radioastronomia, via Gobetti 101, 40129 Bologna (Italy)
5. Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)
6. National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801-0387 (United States)
7. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
8. Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)
9. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
10. Excellence Cluster Universe, Technische Universitaet Muenchen Boltzmannstr. 2, D-85748, Garching (Germany)
11. IASF Milano-INAF, Via Bassini 15, I-20133, Milan (Italy)

We explore the cosmic evolution of radio luminous active galactic nuclei (AGNs) with low radio powers (L {sub 1.4GHz} {approx}< 5 x 10{sup 25} W Hz{sup -1}) out to z = 1.3 using to date the largest sample of {approx}600 low-luminosity radio AGN at intermediate redshift drawn from the VLA-COSMOS survey. We derive the radio-luminosity function for these AGNs, and its evolution with cosmic time assuming two extreme cases: (1) pure luminosity and (2) pure density evolution. The former and latter yield L {sub *} {proportional_to} (1 + z){sup 0.8} {sup {+-}} {sup 0.1}, and {phi}{sub *} {proportional_to} (1 + z){sup 1.1} {sup {+-}} {sup 0.1}, respectively, both implying a fairly modest change in properties of low-radio-power AGNs since z = 1.3. We show that this is in stark contrast with the evolution of powerful (L {sub 1.4GHz} > 5 x 10{sup 25} W Hz{sup -1}) radio AGN over the same cosmic time interval, constrained using the 3CRR, 6CE, and 7CRS radio surveys by Willot et al. We demonstrate that this can be explained through differences in black hole fueling and triggering mechanisms, and a dichotomy in host galaxy properties of weak and powerful AGNs. Our findings suggest that high- and low-radio-power AGN activities are triggered in different stages during the formation of massive red galaxies. We show that weak radio AGN occur in the most massive galaxies already at z {approx} 1, and they may significantly contribute to the heating of their surrounding medium and thus inhibit gas accretion onto their host galaxies, as recently suggested for the 'radio mode' in cosmological models.

• OSTI ID: 21296226
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 696; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
BLACK HOLES
COSMOLOGICAL MODELS
COSMOLOGY
GALACTIC EVOLUTION
GALAXIES
LUMINOSITY
RED SHIFT
UNIVERSE