Metallicity and Star Formation Activities of the Interacting System Arp 86 from Observation with MOS on Xinglong 2.16m Telescope

TL;DR

This study analyzes the metallicity and star formation in the interacting galaxy system Arp 86, revealing flattened metallicity gradients due to tidal interactions and highlighting the starburst activity in the companion galaxy NGC 7752.

Contribution

First spectroscopic analysis of Arp 86 showing how tidal interactions flatten metallicity gradients and induce starbursts in companion galaxies.

Findings

Flatter oxygen abundance gradient compared to normal galaxies.

NGC 7752 is undergoing a galaxy-wide starburst.

Identification of a potential new member galaxy with similar properties.

Abstract

We present an analysis of the metallicity and star formation activities of HII regions in the interacting system Arp 86, based on the first scientific observation of the multi-object spectroscopy on the 2.16m Telescope at Xinglong Observatory. We find that the oxygen abundance gradient in Arp 86 is flatter than that in normal disk galaxies, which confirms that gas inflows caused by tidal forces during encounters can flatten the metallicity distributions in galaxies. The companion galaxy NGC 7752 is currently experiencing a galaxy-wide starburst with higher surface density of star formation rate than the main galaxy NGC 7753, which can be explained that the companion galaxy is more susceptible to the effects of interaction than the primary. We also find that the galaxy 2MASX J23470758+2926531 has similar abundance and star formation properties to NGC 7753, and may be a part of the Arp 86 system.