HI content and star formation in the interacting galaxy Arp86

TL;DR

This study uses GMRT observations to analyze the distribution of neutral hydrogen and radio continuum in the interacting galaxy system Arp86, revealing tidal features, star formation regions, and potential tidal dwarf galaxy formation.

Contribution

First detailed GMRT multi-frequency study of Arp86's HI and radio continuum, highlighting tidal interactions and star formation links.

Findings

HI tails and bridges due to tidal interactions

High HI column densities in star-forming regions

Detection of a possible tidal dwarf galaxy

Abstract

We present the results of Giant Metrewave Radio Telescope (GMRT) observations of the interacting system Arp86 in both neutral atomic hydrogen, HI, and in radio continuum at 240, 606 and 1394 MHz. In addition to HI emission from the two dominant galaxies, NGC7752 and NGC7753, these observations show a complex distribution of HI tails and bridges due to tidal interactions. The regions of highest column density appear related to the recent sites of intense star formation. HI column densities $\sim1-$1.5 $\times10^{21}$ cm$^{-2}$ have been detected in the tidal bridge which is bright in Spitzer image as well. We also detect HI emission from the galaxy 2MASX J23470758+2926531, which is shown to be a part of this system. We discuss the possibility that this could be a tidal dwarf galaxy. The radio continuum observations show evidence of a non-thermal bridge between NGC7752 and NGC7753, and a radio source in the nuclear region of NGC7753 consistent with it having a LINER nucleus.