Kiloparsec-scale emission in the narrow-line Seyfert 1 galaxy Mrk 783

¹ Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
e-mail: enrico.congiu@phd.unipd.it; marco.berton@unipd.it
² INAF–Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy
³ INAF–Istituto di Radioastronomia, via Gobetti 101, 40129 Bologna, Italy
⁴ Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA
⁵ National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Post Bag 3, Ganeshkhind, 411007 Pune, India
⁶ Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907, USA
⁷ Aalto University Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
⁸ Aalto University Department of Electronics and Nanoengineering, PO Box 15500, 00076 Aalto, Finland

Received: 14 February 2017
Accepted: 30 April 2017

Abstract

We present the first results of a radio survey of 79 narrow-line Seyfert 1 (NLS1) carried out with the Karl G. Jansky Very Large Array (JVLA) at 5 GHz in A configuration aimed at studying the radio properties of these sources. We report the detection of extended emission in one object: Mrk 783. This is intriguing, since the radio-loudness parameter R of this object is close to the threshold between radio-quiet and radio-loud active galactic nuclei (AGN). The galaxy is one of the few NLS1 showing such an extended emission at z < 0.1. The radio emission is divided into a compact core component and an extended component, observed on both sides of the nucleus and extending from 14 kpc southeast to 12 kpc northwest. There is no sign of a collimated jet and the shape of the extended component is similar to those of some Seyfert galaxies. The properties of the emission are compatible with a relic produced by the intermittent activity cycle of the AGN.