On the Encounter between the GASP Galaxy JO36 and the Radio Plume of GIN 049

Abstract

We report the serendipitous discovery of an unprecedented interaction between the radio lobe of a radio galaxy and a spiral galaxy. The discovery was made thanks to LOFAR observations at 144 MHz of the galaxy cluster A160 ( z = 0.04317) provided by the LOFAR Two-metre Sky Survey. The new low-frequency observations revealed that one of the radio plumes of the central galaxy GIN 049 overlaps the spiral galaxy JO36. Previous studies carried out with MUSE revealed that the warm ionized gas in the disk of JO36, traced by the H α emission, is severely truncated with respect to the stellar disk. We further explore this unique system by including new uGMRT observations at 675 MHz to map the spectral index. The emerging scenario is that JO36 has interacted with the radio plume in the past 200–500 Myr. The encounter resulted in a positive feedback event for JO36 in the form of a star formation rate burst of ∼14 M _⊙ yr ^−1 . In turn, the galaxy passage left a trace in the radio-old plasma by reshaping the old relativistic plasma via magnetic draping.

Keywords

• Radio astronomy
• Radio galaxies
• Galactic and extragalactic astronomy
• Giant radio galaxies
• Fanaroff-Riley radio galaxies
• Galaxy evolution