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

## TL;DR

This study reports the first detection of kiloparsec-scale extended radio emission in the NLS1 galaxy Mrk 783, suggesting relic activity from intermittent AGN activity cycles, based on JVLA observations.

## Contribution

First radio survey of NLS1 galaxies with JVLA, identifying extended emission in Mrk 783 and analyzing its properties.

## Key findings

- Extended emission spans 14 kpc to 12 kpc on both sides of the nucleus.
- No collimated jet observed, shape similar to Seyfert galaxies.
- Emission likely from relics of intermittent AGN activity.

## 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 in a compact core component and an extended component, observed on both sides of the nucleus and extending from 14 kpc south-east to 12 kpc north-west. 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.