Pairwise dwarf galaxy formation and galaxy downsizing: some clues from extremely metal-poor Blue Compact Dwarf galaxies

TL;DR

This paper explores the formation and evolution of extremely metal-poor Blue Compact Dwarf galaxies, suggesting that their pairwise formation and interactions play a key role in their development and galaxy downsizing.

Contribution

It introduces the hypothesis that pairwise formation and mild interactions significantly influence the evolution of XBCDs, providing a new framework for understanding their development.

Findings

XBCDs often form galaxy pairs with similar properties

Pairwise formation may lead to synchronized evolution

Interactions could trigger star formation episodes

Abstract

Some of the extremely metal-poor Blue Compact Dwarf galaxies (XBCDs) in the nearby universe form galaxy pairs with remarkably similar properties. This fact points to an intriguing degree of synchronicity in the formation history of these binary dwarf galaxies and raises the question as to whether some of them form and co-evolve pairwise (or in loose galaxy groups), experiencing recurrent mild interactions and minor tidally induced star formation episodes throughout their evolution. We argue that this hypothesis offers a promising conceptual framework for the exploration of the retarded previous evolution and recent dominant formation phase of XBCDs.