Ionized gas and sources of its ionization in the Irr galaxy IC 10

TL;DR

This study analyzes the emission spectra of HII regions in the starburst galaxy IC 10 to determine properties of ionizing sources, star cluster parameters, and chemical abundances using advanced spectroscopic observations.

Contribution

It provides new estimates of star cluster masses, ages, and oxygen abundances in IC 10 based on modern emission-line models and detailed spectroscopic data.

Findings

Determined masses and ages of ionizing star clusters.

Estimated the stellar mass needed for gas ionization in HII regions.

New measurements of oxygen abundance in IC 10's HII regions.

Abstract

IC 10 is the nearest starburst irregular galaxy remarkable for its anomalously high number of WR stars. We report the results of an analysis of the emission spectra of HII-regions ionized by star clusters and WR stars based on observations made with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences using MPFS field spectrograph and SCORPIO focal reducer operating in the slit spectrograph mode. We determine the masses and ages of ionizing star clusters in the violent star-forming region of the galaxy in terms of the new evolutionary models of emission-line spectra of HII-regions developed by Martin-Manjon et al. (2010). We estimate the amount of stars needed to ionize the gas in the brightest HII-region HL 111 and report new determinations of oxygen abundance in HII regions.