HerMES: SPIRE emission from radio-selected active galactic nuclei
MetadataShow full item record
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2011 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
We examine the rest-frame far-infrared emission from powerful radio sources with 1.4-GHz luminosity densities of 25 ≤ log(L1.4/W Hz−1) ≤ 26.5 in the extragalactic Spitzer First Look Survey field. We combine Herschel/SPIRE flux densities with Spitzer/Infrared Array Camera and Multiband Imaging Photometer for Spitzer infrared data to obtain total ( m) infrared luminosities for these radio sources. We separate our sources into a moderate, 0.4 < z < 0.9, and a high, 1.2 < z < 3.0, redshift sub-sample and we use Spitzer observations of a z < 0.1 3CRR sample as a local comparison. By comparison to numbers from the Square Kilometre Array (SKA) Simulated Skies, we find that our moderate-redshift sample is complete and our high-redshift sample is 14 per cent complete. We constrain the ranges of mean star formation rates (SFRs) to be 3.4–4.2, 18–41 and 80–581 M☉ yr−1 for the local, moderate- and high-redshift samples, respectively. Hence, we observe an increase in the mean SFR with increasing redshift which we can parametrize as ~(1 + z)Q, where Q = 4.2 ± 0.8. However, we observe no trends of mean SFR with radio luminosity within the moderate- or high-redshift bins. We estimate that radio-loud active galactic nuclei (AGN) in the high-redshift sample contribute 0.1–0.5 per cent to the total SFR density at that epoch. Hence, if all luminous starbursts host radio-loud AGN we infer a radio-loud phase duty cycle of 0.001–0.005.
Showing items related by title, author, creator and subject.
Wylezalek, D.; Galametz, A.; Stern, D.; Vernet, J.; De Breuck, C.; Seymour, Nick; Brodwin, M.; Eisenhardt, P.; Gonzalez, A.; Hatch, N.; Jarvis, M.; Rettura, A.; Stanford, S.; Stevens, J. (2013)We report the first results from the Clusters Around Radio-Loud AGN program, a Cycle 7 and 8 Spitzer Space Telescope snapshot program to investigate the environments of a large sample of obscured and unobscured luminous ...
Middelberg, E.; Norris, R.; Hales, C.; Seymour, Nick; Johnston-Hollitt, M.; Huynh, M.; Lenc, E.; Mao, M. (2010)Context. Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4GHz, but that are invisible at 3.6µm when using sensitive Spitzer observations with µJy sensitivities. Their nature ...
Ultra steep spectrum radio sources in the lockman hole: Servs identifications and redshift distribution at the faintest radio fluXESAfonso, J.; Bizzocchi, L.; Ibar, E.; Grossi, M.; Simpson, C.; Chapman, S.; Jarvis, M.; Rottgering, H.; Norris, R.; Dunlop, J.; Ivison, R.; Messias, H.; Pforr, J.; Vaccari, M.; Seymour, Nick; Best, P.; Gonzlez-Solares, E.; Farrah, D.; Fernandes, C.; Huang, J.; Lacy, M.; Maraston, C.; Marchetti, L.; Mauduit, J.; Oliver, S.; Rigopoulou, D.; Stanford, S.; Surace, J.; Zeimann, G. (2011)Ultra steep spectrum (USS) radio sources have been successfully used to select powerful radio sources at high redshifts (z ~>2). Typically restricted to large-sky surveys and relatively bright radio flux densities, it has ...