e-MERLIN and VLBI observations of the luminous infrared galaxy IC 883: a nuclear starburst and an AGN candidate revealed

: Romero-Canizales C, Perez-Torres MA, Alberdi A, Argo MK, Beswick RJ, Kankare E, Batejat F, Efstathiou A, Mattila S, Conway JE, Garrington ST, Muxlow TWB, Ryder SD, Vaisanen P

Publisher: EDP SCIENCES S A

: 2012

: Astronomy and Astrophysics

: ASTRONOMY & ASTROPHYSICS

: ASTRON ASTROPHYS

: ARTN A72

: 543

: 9

: 0004-6361

DOI: https://doi.org/10.1051/0004-6361/201218816

Results. The circumnuclear regions traced by e-MERLIN at 6.9 GHz have an extension of similar to 1 kpc, at a position angle of 130 degrees, and show a striking double-sided structure, which very likely corresponds to a warped rotating ring, in agreement with previous studies. Our e-EVN observations at 5 GHz and complementary archival VLBI data at 5 GHz and 8.4 GHz, reveal various milliarcsec compact components in the nucleus of IC 883. A single compact source, an AGN candidate, dominates the emission at both nuclear and circumnuclear scales, as imaged with the e-EVN and e-MERLIN, respectively. The other milliarcsec components are strongly indicative of ongoing nuclear CCSN activity. Our e-EVN observations also provided upper limits to the radio luminosity of the two SNe in IC 883 recently discovered at NIR wavelengths. We refine the classification of SN 2011hi as a Type IIP SN according to our latest epoch of Gemini North observations acquired in 2012, in agreement with a low-luminosity radio SN nature. We estimate a CCSN rate lower limit of 1.1(-0.6)(+1.3) yr(-1) for the entire galaxy, based on three nuclear radio SNe and the circumnuclear SNe 2010cu and 2011hi.