HerMES: SPIRE emission from radio-selected active galactic nuclei

May 2011 • 2011MNRAS.413.1777S

Authors • Seymour, N. • Symeonidis, M. • Page, M. J. • Amblard, A. • Arumugam, V. • Aussel, H. • Blain, A. • Bock, J. • Boselli, A. • Buat, V. • Castro-Rodríguez, N. • Cava, A. • Chanial, P. • Clements, D. L. • Conley, A. • Conversi, L. • Cooray, A. • Dowell, C. D. • Dwek, E. • Eales, S. • Elbaz, D. • Franceschini, A. • Glenn, J. • Solares, E. A. González • Griffin, M. • Hatziminaoglou, E. • Ibar, E. • Isaak, K. • Ivison, R. J. • Lagache, G. • Levenson, L. • Lu, N. • Madden, S. • Maffei, B. • Mainetti, G. • Marchetti, L. • Nguyen, H. T. • O'Halloran, B. • Oliver, S. J. • Omont, A. • Panuzzo, P. • Papageorgiou, A. • Pearson, C. P. • Pérez-Fournon, I. • Pohlen, M. • Rawlings, J. I. • Rizzo, D. • Roseboom, I. G. • Rowan-Robinson, M. • Schulz, B. • Scott, Douglas • Shupe, D. L. • Smith, A. J. • Stevens, J. A. • Trichas, M. • Tugwell, K. E. • Vaccari, M. • Valtchanov, I. • Vigroux, L. • Wang, L. • Wright, G. • Xu, C. K. • Zemcov, M.

Abstract • We examine the rest-frame far-infrared emission from powerful radio sources with 1.4-GHz luminosity densities of 25 ≤ log(L_1.4/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.

For reference, 2 per cent of the radio sources with unknown redshifts have significant detections in the SPIRE wavebands.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2011MNRAS.413.1777S
• PDF https://academic.oup.com/mnras/pdf-lookup/doi/10.1111/j.1365-2966.2011.18253.x
• PREPRINT http://arxiv.org/abs/1012.5085
• DATA http://archives.esac.esa.int/hsa/whsa/?ACTION=PUBLICATION&ID=2011MNRAS.413.1777S
• DATA https://irsa.ipac.caltech.edu/bibdata/2011/S/2011MNRAS.413.1777S.html
• ELECTR http://dx.doi.org/10.1111/j.1365-2966.2011.18253.x