Unveiling an old disk around a massive young leaking blueberry in SDSS-IV MaNGA

TL;DR

This study reveals a low-surface brightness stellar disk around a blueberry galaxy, linking it to local starburst dwarf galaxies and suggesting a common evolutionary path for these galaxy types.

Contribution

It uncovers a previously undetected old stellar disk around a blueberry galaxy, connecting local blue compact dwarfs and high-redshift galaxy analogs.

Findings

Detected a low-surface brightness stellar host with old stars.

Found kinematic misalignment between gas and stars.

Linked blueberries to local starburst dwarf galaxy evolution.

Abstract

Extreme emission-line galaxies, such as blue compact dwarfs (BCDs), Green Peas (GPs) and blueberries in the local Universe are the potential candidates to understand the nature of galaxies that re-ionized the early Universe. Being low-mass, metal-poor starburst systems they are understood as local analogs of the high redshift Lyman Continuum (LyC) and Lyman-${\alpha}$ emitters (LAEs). Even with their proximity to us, we know little about their spatially resolved properties, most of the blueberries and GPs are indeed compact, remain unresolved. Here, we report the detection of a disk-like lower-surface brightness (LSB) stellar host with very old population around a blueberry LAE system using broad i-band imaging and integral field spectroscopic data from SDSS and SDSS-IV MaNGA surveys, respectively. The LSB stellar host is structurally similar to that observed around15 local starburst BCDs. Furthermore, the kinematics of the studied blueberry source bear sign of misalignment between the gas and stellar components. Our findings establish an intriguing thread connecting the blueberry and an LSB disk with old stellar population, and suggest that blueberries and their high redshift counterparts such as GPs do not represent peculiar cases of dwarf galaxy evolution. In fact, with respect to the structural properties of their host galaxies, they are compatible with a common evolutionary track of the main population of local BCDs.