Unveiling the AGN in IC 883: discovery of a parsec-scale radio jet
Journal article, 2017
IC 883 is a luminous infrared galaxy (LIRG) classified as a starburst- active galactic nucleus (AGN) composite. In a previous study, we detected a low- luminosity AGN (LLAGN) radio candidate. Here, we report on our radio follow- up at three frequencies that provides direct and unequivocal evidence of the AGN activity in IC 883. Our analysis of archival X-ray data, together with the detection of a transient radio source with luminosity typical of bright supernovae, gives further evidence of the ongoing star formation activity, which dominates the energetics of the system. At sub- parsec scales, the radio nucleus has a core-jet morphology with the jet being a newly ejected component showing a subluminal proper motion of 0.6-1 c. The AGN contributes less than 2 per cent of the total IR luminosity of the system. The corresponding Eddington factor is similar to 10(-3), suggesting this is a low-accretion rate engine, as often found in LLAGNs. However, its high bolometric luminosity (similar to 10(44) erg s(-1)) agrees better with a normal AGN. This apparent discrepancy may just be an indication of the transition nature of the nucleus from a system dominated by star formation, to an AGN-dominated system. The nucleus has a strongly inverted spectrum and a turnover at similar to 4.4 GHz, thus qualifying as a candidate for the least luminous (L(5.0)GHz similar to 6.3 x 10(28) erg s(-1) Hz(-1)) and one of the youngest (similar to 3 x 10(3) yr) gigahertz-peaked spectrum (GPS) sources. If the GPS origin for the IC 883 nucleus is confirmed, then advanced mergers in the LIRG category are potentially key environments to unveil the evolution of GPS sources into more powerful radio galaxies.
galaxies: active
galaxies: individual: IC 883
galaxies: nuclei
radio continuum: galaxies
galaxies: jets
Author
C. Romero-Cañizales
Pontificia Universidad Catolica de Chile
Millennium Institute of Astrophysics
Diego Portales University
Antxon Alberdi
Spanish National Research Council (CSIC)
C. Ricci
Pontificia Universidad Catolica de Chile
P. Arevalo
University of Valparaíso
Miguel Angel Perez-Torres
Spanish National Research Council (CSIC)
University of Zaragoza
John Conway
Chalmers, Earth and Space Sciences, Onsala Space Observatory
R. J. Beswick
University of Manchester
M. Bondi
Istituto nazionale di astrofisica (INAF)
T .W. B. Muxlow
University of Manchester
M. K. Argo
University of Manchester
University of Central Lancashire
F. E. Bauer
Millennium Institute of Astrophysics
Space Science Institute
Pontificia Universidad Catolica de Chile
A. Efstathiou
European University Cyprus
R. Herrero-Illana
Spanish National Research Council (CSIC)
European Southern Observatory Santiago
S. Mattila
Tuorla Observatory
S. D. Ryder
Australian Astronomical Observatory
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 467 2 2504-2516Advanced Radio Astronomy in Europe (RADIONET3)
European Commission (EC) (EC/FP7/283393), 2012-01-01 -- 2015-12-31.
Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.1093/mnras/stx224