PKS1932-46: a radio source in an interacting group?

Abstract

We present the results of a multiwavelength study of the z=0.23 radio source PKS1932-46. VIMOS IFU spectroscopy is used to study the morphology, kinematics and ionisation state of the EELR surrounding this source, and also a companion galaxy at a similar redshift. Near- and far-IR imaging observations obtained using the NTT and SPITZER are used to analyse the underlying galaxy morphologies and the nature of the AGN. The host galaxy is identified as an ~M* elliptical. Combining Spitzer mid-IR with X-ray, optical and near-IR imaging observations of this source, we conclude that its AGN is underluminous for a radio source of this type, despite its status as a BLRG. However, given its relatively large [OIII] luminosity it is likely that the AGN was substantially more luminous in the recent past (<10^4 years ago). The EELR is remarkably extensive and complex, reminiscent of the systems observed around sources at higher redshifts/radio powers, and the gas is predominantly ionised by a mixture of AGN photoionisation and emission from young stars. We confirm the presence of a series of star-forming knots extending N-S from the host galaxy, with more prodigious star formation occuring in the merging companion galaxy to the northeast, which has sufficient luminosity at mid- to far-IR wavelengths to be classified as a LIRG. The most plausible explanation of our observations is that PKS1932-46 is a member of an interacting galaxy group, and that the impressive EELR is populated by star-forming, tidal debris. We suggest that the AGN itself may currently be fuelled by material associated either with the current interaction, or with a previous merger event. Surprisingly, it is the companion object, rather than the radio source host galaxy, which is undergoing the bulk of the star formation activity within the group.

15 pages, 14 figures (compressed for astro-ph, 1 colour). Accepted for publication in MNRAS. Abstract abridged

References in corpus (44)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Stellar population synthesis at the resolution of 2003
• The Spitzer Space Telescope Mission
• Theoretical Modeling of Starburst Galaxies
• Modeling feedback from stars and black holes in galaxy mergers
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• The Relation between Black Hole Mass, Bulge Mass, and Near-Infrared Luminosity
• Estimating Black Hole Masses in Active Galaxies Using the Halpha Emission Line
• Quasars, their host galaxies, and their central black holes
• The K-Band Galaxy Luminosity Function
• Reduction Algorithms for the Multiband Imaging Photometer for Spitzer
• A comparative HST imaging study of the host galaxies of radio-quiet quasars, radio-loud quasars and radio galaxies: Paper I
• Dusty, Radiation Pressure Dominated Photoionization. I. Model Description, Structure And Grids
• Point Source Extraction with MOPEX
• The black-hole masses of Seyfert galaxies and quasars
• Evolutionary tracks of FRII sources through the P-D diagram
• Dusty, Radiation Pressure Dominated Photoionization. II. Multi-Wavelength Emission Line Diagnostics for Narrow Line Regions
• Near-infrared imaging and the K-z relation for radio galaxies in the 7C Redshift Survey
• An X-ray Spectral Survey of Radio-Loud AGN With ASCA
• HST, radio and infrared observations of 28 3CR radio galaxies at redshift z ~ 1: I. Old stellar populations in central cluster galaxies
• The VVDS data reduction pipeline: introducing VIPGI, the VIMOS Interactive Pipeline and Graphical Interface
• Ionisation, shocks and evolution of the emission line gas of distant 3CR radio galaxies
• Spectroscopy of the near-nuclear regions of Cygnus A: estimating the mass of the supermassive black hole
• Kinematically quiet halos around z~2.5 radio galaxies. Keck spectroscopy
• The co-evolution of the obscured quasar PKS1549-79 and its host galaxy: evidence for a high accretion rate and warm outflow
• A new look at the isotropy of narrow line emission in extragalactic radio sources
• The large scale distribution of warm ionized gas around nearby radio galaxies with jet-cloud interactions
• The properties of the young stellar populations in powerful radio galaxies at low and intermediate redshifts
• Infrared Magnitude-Redshift Relations for Luminous Radio Galaxies
• The balance between shocks and AGN photoionization in radio sources and its relation to the radio size
• Deep spectroscopy of z~1 6C radio galaxies - I. The effects of radio power and size on the properties of the emission line gas
• Ultraviolet HST Snapshot Survey of 3CR Radio Source Counterparts at Low Redshift
• The VIMOS Integral Field Unit: data reduction methods and quality assessment
• Metal enriched gaseous halos around distant radio galaxies: Clues to feedback in galaxy formation
• Probing the absorbing haloes around two high-redshift radio galaxies with VLT-UVES
• The heating mechanism for the warm/cool dust in powerful, radio-loud AGN
• Integral Field Spectroscopy of the Extended Emission-Line Region of 4C 37.43
• The Extended Emission-Line Region of 4C 37.43
• Infrared photometry of z~1 3C quasars
• Deep spectroscopy of z~1 6C radio galaxies - II. Breaking the redshift-radio power degeneracy
• The giant star forming halo associated with the radio galaxy PKS1932-46
• HST and UKIRT imaging observations of z~1 6C radio galaxies - II. Galaxy morphologies and the alignment effect
• Shocks, illumination cones and intrinsic gas structures in the extreme radio galaxy 3C265
• Deviations from passive evolution - star formation and the UV excess in z~1 radio galaxies

Cited by in corpus (12)

• The subarcsecond mid-infrared view of local active galactic nuclei: I. The N- and Q-band imaging atlas
• Radio AGN in the local universe: unification, triggering and evolution
• An X-ray survey of the 2Jy sample. I: is there an accretion mode dichotomy in radio-loud AGN?
• The optical morphologies of the 2Jy sample of radio galaxies: evidence for galaxy interactions
• Starburst radio galaxies: general properties, evolutionary histories and triggering
• The origin of the infrared emission in radio galaxies II: analysis of mid- to far-infrared Spitzer observations of the 2Jy sample
• Spitzer Mid-IR Spectroscopy of Powerful 2Jy and 3CRR Radio Galaxies. II. AGN Power Indicators and Unification
• A near-IR study of the host galaxies of 2Jy radio sources at 0.03 < z < 0.5: I - the data
• Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131-36)
• PKS2250-41: a case study for triggering
• MUSE 3D Spectroscopy and Kinematics of the gigahertz peaked spectrum Radio Galaxy PKS 1934-63: Interaction, Recently Triggered AGN and Star Formation
• Powerful Radio Sources in the Southern Sky. I. Optical Identifications