The HI Chronicles of LITTLE THINGS BCDs II: The Origin of IC 10's HI Structure

TL;DR

This study uses high-resolution VLA and GBT data to analyze the complex HI structure and kinematics of the dwarf galaxy IC 10, exploring its possible origins including interaction, merger, or accretion.

Contribution

It provides detailed kinematic and morphological analysis of IC 10's HI, proposing that its structure results from an advanced merger or ongoing accretion.

Findings

IC 10's HI is highly disturbed with distinct kinematic features.

The galaxy's HI structure suggests an advanced merger or accretion process.

Multiple kinematic anomalies indicate complex interaction history.

Abstract

In this paper we analyze Very Large Array (VLA) telescope and Green Bank Telescope (GBT) atomic hydrogen (HI) data for the LITTLE THINGS(1) blue compact dwarf galaxy IC 10. The VLA data allow us to study the detailed HI kinematics and morphology of IC 10 at high resolution while the GBT data allow us to search the surrounding area at high sensitivity for tenuous HI. IC 10's HI appears highly disturbed in both the VLA and GBT HI maps with a kinematically distinct northern HI extension, a kinematically distinct southern plume, and several spurs in the VLA data that do not follow the general kinematics of the main disk. We discuss three possible origins of its HI structure and kinematics in detail: a current interaction with a nearby companion, an advanced merger, and accretion of intergalactic medium. We find that IC 10 is most likely an advanced merger or a galaxy undergoing accretion. 1:Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey; https://science.nrao.edu/science/surveys/littlethings