The origin of the infrared emission in radio galaxies I: new mid- to far-infrared and radio observations of the 2Jy sample

Abstract

As part of a large study to investigate the nature of the longer wavelength continuum emission of radio-loud AGN, we present new mid to far-infrared (MFIR) and high frequency radio observations for a complete sample of 2Jy powerful, southern radio galaxies at intermediate redshifts (0.05<z<0.7). Utilizing the sensitivity of the Spitzer Space Telescope, we have made deep MIPS observations at the wavelengths of 24, 70 and 160 microns, detecting 100% of our sample at 24 microns, and 90% at 70 microns. This high detection rate at MFIR wavelengths is unparallelled in samples of intermediate redshift radio galaxies. Complementing these results, we also present new high frequency observations (15 to 24Ghz) from the Australia Telescope Compact Array (ATCA) and the Very Large Array (VLA), which are used to investigate the potential contamination of the MFIR continuum by non-thermal synchrotron emission. With the latter observations we detect the compact cores in 59% of our complete sample, and deduce that non-thermal contamination of the MFIR continuum is significant in a maximum of 30% of our total sample. MFIR fluxes, radio fluxes and spectral energy distributions for the complete sample are presented here, while in a second paper we will analyse these data and discuss the implications for our understanding of the heating mechanism for the warm/cool dust, star formation in the host galaxies, and the unified schemes for powerful radio sources.

23 pages, 8 figures, Accepted for publication in the Astrophysical Journal

References in corpus (4)

• The Massive Hosts of Radio Galaxies Across Cosmic Time
• The co-evolution of the obscured quasar PKS1549-79 and its host galaxy: evidence for a high accretion rate and warm outflow
• The properties of the young stellar populations in powerful radio galaxies at low and intermediate redshifts
• On the nature of optical nuclei in FR I radio-galaxies from ACS/HST imaging polarimetry

Cited by in corpus (14)

• A representative survey of the dynamics and energetics of FRII radio galaxies
• AGN-driven outflows and the AGN feedback efficiency in young radio galaxies
• The Spitzer view of FR-I radio galaxies: on the origin of the nuclear mid-infrared continuum
• Spitzer Mid-IR Spectroscopy of Powerful 2Jy and 3CRR Radio Galaxies. II. AGN Power Indicators and Unification
• Interplanetary Scintillation with the Murchison Widefield Array I: A sub-arcsecond Survey over 900 square degrees at 79 and 158 MHz
• The dust masses of powerful radio galaxies: clues to the triggering of their activity
• SUPER V. ALMA continuum observations of z~2 AGN and the elusive evidence of outflows influencing star formation
• The impact of ionised outflows from z$\sim$2.5 quasars is not through instantaneous in-situ quenching: the evidence from ALMA and VLT/SINFONI
• An X-ray survey of the 2Jy sample. II: X-ray emission from extended structures
• High energy emission component, population, and contribution to the extragalactic gamma-ray background of gamma-ray emitting radio galaxies
• HI absorption at z~0.7 against the lobe of the powerful radio galaxy PKS 0409-75
• Near-infrared Hubble Space Telescope polarimetry of a complete sample of narrow-line radio galaxies
• Deep Herschel observations of the 2Jy sample: assessing the non-thermal and AGN contributions to the far-IR continuum
• Spatial variations of magnetic field along active galactic nuclei jets on sub-pc to Mpc scales