FAR-INFRARED AND MOLECULAR CO EMISSION FROM THE HOST GALAXIES OF FAINT QUASARS AT z {approx} 6
- National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States)
- Institute de Radioastronomie Millimetrique, St. Martin d'Heres F-38406 (France)
- Max-Planck-Institute for Astronomy, Koenigsstuhl 17, 69117 Heidelberg (Germany)
- Institut d'Astrophysique de Paris, CNRS and Universite Pierre et Marie Curie, Paris (France)
- California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
- Argelander-Institut fuer Astronomie, University of Bonn, Auf dem Huegel 71, 53121 Bonn (Germany)
- Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 71, 53121 Bonn (Germany)
- European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile)
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
- Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
We present new millimeter and radio observations of nine z {approx} 6 quasars discovered in deep optical and near-infrared surveys. We observed the 250 GHz continuum in eight of the nine objects and detected three of them. New 1.4 GHz radio continuum data have been obtained for four sources, and one has been detected. We searched for molecular CO (6-5) line emission in the three 250 GHz detections and detected two of them. Combined with previous millimeter and radio observations, we study the far-infrared (FIR) and radio emission and quasar-host galaxy evolution with a sample of 18 z {approx} 6 quasars that are faint at UV and optical wavelengths (rest-frame 1450 A magnitudes of m{sub 1450} {>=} 20.2). The average FIR-to-active galactic nucleus (AGN) UV luminosity ratio of this faint quasar sample is about two times higher than that of the bright quasars at z {approx} 6 (m{sub 1450} < 20.2). A fit to the average FIR and AGN bolometric luminosities of both the UV/optically faint and bright z {approx} 6 quasars, and the average luminosities of samples of submillimeter/millimeter-observed quasars at z {approx} 2-5, yields a relationship of L{sub FIR} {approx} L{sub bol}{sup 0.62}. Five of the 18 faint z {approx} 6 quasars have been detected at 250 GHz. These 250 GHz detections, as well as most of the millimeter-detected optically bright z {approx} 6 quasars, follow a shallower trend of L{sub FIR} {approx} L{sub bol}{sup 0.45} defined by the starburst-AGN systems in local and high-z universe. The millimeter continuum detections in the five objects and molecular CO detections in three of them reveal a few x 10{sup 8} M{sub sun} of FIR-emitting warm dust and 10{sup 10} M{sub sun} of molecular gas in the quasar host galaxies. All these results argue for massive star formation in the quasar host galaxies, with estimated star formation rates of a few hundred M{sub sun} yr{sup -1}. Additionally, the higher FIR-to-AGN luminosity ratio found in these 250 GHz detected faint quasars also suggests a higher ratio between star formation rate and supermassive black hole accretion rate than the UV/optically most luminous quasars at z {approx} 6.
- OSTI ID:
- 21582850
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 142, Issue 4; Other Information: DOI: 10.1088/0004-6256/142/4/101; ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
HOST GALAXIES, CLUSTERING, EDDINGTON RATIOS, AND EVOLUTION OF RADIO, X-RAY, AND INFRARED-SELECTED AGNs
A CLOSER VIEW OF THE RADIO-FIR CORRELATION: DISENTANGLING THE CONTRIBUTIONS OF STAR FORMATION AND ACTIVE GALACTIC NUCLEUS ACTIVITY
Related Subjects
COSMOLOGY AND ASTRONOMY
BLACK HOLES
BOLOMETERS
DUSTS
EMISSION
GALACTIC EVOLUTION
GALAXIES
GHZ RANGE
INFRARED SURVEYS
LUMINOSITY
QUASARS
RED SHIFT
STARS
UNIVERSE
COSMIC RADIO SOURCES
EVOLUTION
FREQUENCY RANGE
GEOLOGIC SURVEYS
GEOPHYSICAL SURVEYS
MEASURING INSTRUMENTS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES