Optical Observations of M81 Galaxy Group in Narrow Band [SII] and H_alpha Filters: Holmberg IX

TL;DR

This study used narrow band [SII] and Hα imaging to investigate Holmberg IX in the M81 group, finding no supernova remnants but identifying potential new HII regions, enhancing understanding of the galaxy's interstellar medium.

Contribution

First narrow band imaging survey of Holmberg IX focusing on supernova remnants and HII regions, providing new insights into its interstellar medium.

Findings

No supernova remnants detected besides known sources.

Identification of several potential new HII regions.

Enhanced understanding of Holmberg IX's interstellar environment.

Abstract

We present observations of the nearby tidal dwarf galaxy Holmberg IX in M81 galaxy group in narrow band [SII] and H$\alpha$ filters, carried out in March and November 2008 with the 2m RCC telescope at NAO Rozhen, Bulgaria. Our search for resident supernova remnants (identified as sources with enhanced [SII] emission relative to their H$\alpha$ emission) in this galaxy yielded no sources of this kind, besides M&H 10-11 or HoIX X-1. Nevertheless, we found a number of objects with significant H$\alpha$ emission that probably represent uncatalogued HII regions.