DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?
Abstract
Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of {approx}1 {mu}Jy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S{sub 3.6{mu}m} {approx} 0.2 {mu}Jy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.
- Authors:
-
- CSIRO Australia Telescope National Facility, P.O. Box 76, Epping, NSW, 1710 (Australia)
- Observatorio Astronomico de Lisboa, Faculdade de Ciencias, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisbon (Portugal)
- Departamento de Astrofisica, Facultad de CC. Fisicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)
- Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom)
- Infrared Processing and Analysis Center, MS220-6, California Institute of Technology, Pasadena, CA 91125 (United States)
- UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
- Centre for Astrophysics, Science and Technology Research Institute, University of Hertfordshire, Hatfield, Herts, AL10 9AB (United Kingdom)
- NRAO, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
- Institute of Cosmology and Gravitation, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)
- Astronomisches Institut, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44801 Bochum (Germany)
- Mullard Space Science Laboratory, UCL, Holmbury St Mary, Dorking, Surrey, RH5 6NT (United Kingdom)
- Publication Date:
- OSTI Identifier:
- 21578298
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal
- Additional Journal Information:
- Journal Volume: 736; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/736/1/55; Journal ID: ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; FLUX DENSITY; GALACTIC EVOLUTION; GALAXY NUCLEI; NEAR INFRARED RADIATION; RADIOWAVE RADIATION; RED SHIFT; ELECTROMAGNETIC RADIATION; EVOLUTION; INFRARED RADIATION; RADIATIONS
Citation Formats
Norris, Ray P, Mao, Minnie, Afonso, Jose, Cava, Antonio, Farrah, Duncan, Oliver, Seb, Huynh, Minh T, Mauduit, Jean-Christophe, Surace, Jason, Ivison, R J, Jarvis, Matt, Lacy, Mark, Maraston, Claudia, Middelberg, Enno, and Seymour, Nick. DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?. United States: N. p., 2011.
Web. doi:10.1088/0004-637X/736/1/55.
Norris, Ray P, Mao, Minnie, Afonso, Jose, Cava, Antonio, Farrah, Duncan, Oliver, Seb, Huynh, Minh T, Mauduit, Jean-Christophe, Surace, Jason, Ivison, R J, Jarvis, Matt, Lacy, Mark, Maraston, Claudia, Middelberg, Enno, & Seymour, Nick. DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?. United States. https://doi.org/10.1088/0004-637X/736/1/55
Norris, Ray P, Mao, Minnie, Afonso, Jose, Cava, Antonio, Farrah, Duncan, Oliver, Seb, Huynh, Minh T, Mauduit, Jean-Christophe, Surace, Jason, Ivison, R J, Jarvis, Matt, Lacy, Mark, Maraston, Claudia, Middelberg, Enno, and Seymour, Nick. 2011.
"DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?". United States. https://doi.org/10.1088/0004-637X/736/1/55.
@article{osti_21578298,
title = {DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?},
author = {Norris, Ray P and Mao, Minnie and Afonso, Jose and Cava, Antonio and Farrah, Duncan and Oliver, Seb and Huynh, Minh T and Mauduit, Jean-Christophe and Surace, Jason and Ivison, R J and Jarvis, Matt and Lacy, Mark and Maraston, Claudia and Middelberg, Enno and Seymour, Nick},
abstractNote = {Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of {approx}1 {mu}Jy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S{sub 3.6{mu}m} {approx} 0.2 {mu}Jy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.},
doi = {10.1088/0004-637X/736/1/55},
url = {https://www.osti.gov/biblio/21578298},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 736,
place = {United States},
year = {Wed Jul 20 00:00:00 EDT 2011},
month = {Wed Jul 20 00:00:00 EDT 2011}
}