Open AccessSubmillimetre photometry of typical high‐redshift radio quasars
Author(s) -
Rawlings Steve,
Willott Chris J.,
Hill Gary J.,
Archibald Elese N.,
Dunlop James S.,
Hughes David H.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07819.x
Subject(s) - physics , redshift , astrophysics , quasar , photometry (optics) , astronomy , population , luminosity , galaxy , redshift survey , active galactic nucleus , radio galaxy , stars , demography , sociology
We present Submillimetre Common‐User Bolometer Array (SCUBA) photometry of a sample of eight high‐redshift (2.5 ≤ z < 3.5) radio quasars from two redshift surveys: the TexOx‐1000 (or TOOT) Survey and the 7C Redshift Survey (7CRS). Unlike the powerful high‐redshift radio sources observed previously in the submillimetre, these radio sources are typical of those dominating the radio luminosity density of the population. We detect just two of the TOOT/7CRS targets at 850 μm, and one of these detections is probably due to synchrotron emission rather than dust. The population represented by the other six objects is detected in a statistical sense with their average 850‐μm flux density implying that they are similar to low‐redshift, far‐infrared luminous quasars undergoing at most moderate (≲200 M ⊙ yr −1 ) starbursts. By considering all the SCUBA data available for radio sources, we conclude that positive correlations between rest‐frame far‐infrared luminosity L FIR , 151‐MHz luminosity L 151 and redshift z , although likely to be present, are hard to interpret because of subtle selection and classification biases, small number statistics and uncertainties concerning synchrotron contamination and k ‐correction. We argue that there is not yet any compelling evidence for significant differences in the submillimetre properties of radio‐loud and radio‐quiet quasars at high redshift.