Letter to the Editor

Tracing jet–ISM interaction in young AGN: correlations between [O III] λ 5007 Å   and 5-GHz emission

¹ Departamento de Astrofísica Molecular e Infrarroja, Instituto de Estructura de la Materia (CSIC), Madrid, Spain e-mail: labiano@damir.iem.csic.es
² Kapteyn Astronomical Institute, Groningen 9700 AV, The Netherlands
³ Department of Physics, Rochester Institute of Technology, Rochester, NY 14623, USA

Received: 17 June 2008
Accepted: 17 July 2008

Abstract

Aims. I study the interaction between young AGN and their host galaxies based on their ionized gas and radio emission, and analyze possible implications for radio galaxy evolution.

Methods. The [] λ 5007 Å  line and 5-GHz radio properties are compared and studied for a large, representative sample of GPS and CSS (i.e., young) quasars and radio galaxies, and large-scale sources using [] λ 5007 Å  line and 5-GHz radio data from the literature and our own observations.

Results. Several correlations between the [] λ 5007 Å   line and 5-GHz radio emission were found. The main result is that the [] λ 5007 Å   emission is strongly correlated with the GPS/CSS source size, which indicates that the [] λ 5007 Å   emission is enhanced significantly by the jet expansion through the host galaxy ISM. Shocks are the most likely enhancement mechanism, although jet-induced star formation could be also, partly, responsible for the [] λ 5007 Å   emission. The data also suggests that the jet possibly decelerates as it grows, although the correlation expansion speed versus radio size is weak.