The MURALES survey. V. Jet-induced star formation in 3C 277.3 (Coma A)

TL;DR

This study uses VLT/MUSE observations to reveal that the radio galaxy Coma A exhibits widespread star formation likely triggered by its expanding radio outflows, with ionization from shocks and young stars.

Contribution

It provides the first detailed spatially-resolved evidence of jet-induced star formation across an entire radio source in the local Universe.

Findings

Star formation is occurring in five compact knots up to 60 kpc from the host.

Emission line filaments are ionized by shocks and possibly star formation.

Coma A may be a unique local example of jet-triggered galaxy-wide star formation.

Abstract

We present observations obtained with the VLT/MUSE optical integral field spectrograph of the radio source 3C277.3, located at a redshift of 0.085 and associated with the galaxy Coma A. An emission line region fully enshrouds the double-lobed radio source, which is ~60 kpc x 90 kpc in size. Based on the emission line ratios, we identified five compact knots in which the gas ionization is powered by young stars located as far as ~60 kpc from the host. The emission line filaments surrounding the radio emission are compatible with ionization from fast shocks (with a velocity of 350-500 km/s), but a contribution from star formation occurring at the edges of the radio source is likely. Coma A might be a unique example in the local Universe in which the expanding outflow triggers star formation throughout the whole radio source.