The environment of nearby Blue Compact Dwarf Galaxies

TL;DR

This study investigates the environments of nearby blue compact dwarf galaxies, revealing that interactions with other low-luminosity objects or HI clouds likely trigger their starburst activity, challenging the notion of their isolation.

Contribution

The paper provides new deep multiwavelength observations showing interaction features in BCDGs' neutral gas, emphasizing the role of interactions in starburst triggering.

Findings

Interactions with dwarf galaxies or HI clouds are common in BCDGs.

Deep optical and HI observations reveal interactions not visible in shallow images.

Interactions likely trigger star-forming bursts in BCDGs.

Abstract

We are obtaining deep multiwavelength data of a sample of nearby blue compact dwarf galaxies (BCDGs) combining broad-band optical/NIR and H$\alpha$ photometry, optical spectroscopy and 21-cm radio observations. Here we present HI results obtained with the Australia Telescope Compact Array for some BCDGs, all showing evident interaction features in their neutral gas component despite the environment in which they reside. Our analysis strongly suggests that interactions with or between low-luminosity dwarf galaxies or HI clouds are the main trigger mechanism of the star-forming bursts in BCDGs; however these dwarf objects are only detected when deep optical images and complementary HI observations are performed. Are therefore BCDGs real isolated systems?