The discovery of blue-cored dwarf early-type galaxies in isolated environments
arXiv:2302.07808 · doi:10.3847/1538-4357/acbc1c
Abstract
The presence of blue-cored dwarf early-type galaxies (dE(bc)s) in high-density environments supports the scenario of the transformation of infalling late-type galaxies into quiescent dwarf early-type galaxies by environmental effects. While low-density environments lacking environmental processes could not be relevant to the formation of dE(bc)s, we discovered a large sample of rare dE(bc)s in isolated environments at z < 0.01 using the NASA-Sloan Atlas catalog. Thirty-two isolated dE(bc)s were identified by visual inspection of the Sloan Digital Sky Survey images and g - r color profiles. We found that (1) isolated dE(bc)s exhibit similar structural parameters to dE(bc)s in the Virgo cluster; (2) based on the ultraviolet-r color-magnitude relation, color gradients, and optical emission lines of dE(bc)s, isolated dE(bc)s show more vigorous, centrally concentrated SF compared to their counterparts in the Virgo cluster; (3) at a given stellar mass, isolated dE(bc)s tend to have a larger fraction of gas mass than their Virgo counterparts. We discuss a scenario of episodic SF sustained by gas accretion, suggested by Sanchez Almeida et al., in which the star-bursting blue compact dwarf galaxy (BCD)-quiescent BCD (QBCD) cycle can be repeated during the Hubble time. We suggest that, in this cadence, isolated dE(bc)s might be QBCDs at pre- or post-BCD stages. Our results imply that dE(bc)s comprise a mixture of objects with two types of origins, nature or nurture, depending on their environment.
8 pages, 5 figures, accepted for publication in Astrophysical Journal
References in corpus (19)
- Cold streams in early massive hot haloes as the main mode of galaxy formation
- Cold gas accretion in galaxies
- Star formation sustained by gas accretion
- The cold interstellar medium of galaxies in the Local Universe
- Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. I. On the possible disk nature of bright early-type dwarfs
- A Model for Star Formation, Gas Flows and Chemical Evolution in Galaxies at High Redshifts
- Breathing in Low Mass Galaxies: A Study of Episodic Star Formation
- Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. II. Early-type dwarfs with central star formation
- The Extended Virgo Cluster Catalog
- Simulations of the formation and evolution of isolated dwarf galaxies
- Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-Type Galaxies from the SMAKCED Project II. The Survey and a Systematic Analysis of Kinematic Anomalies and Asymmetries
- Catalog of Visually Classified Galaxies in the Local () Universe
- Search for Blue Compact Dwarf Galaxies During Quiescence
- The properties of early-type galaxies in the Ursa Major cluster
- A Study on the Chemical Properties of Blue Compact Dwarf Galaxies
- Young stellar populations in early-type dwarf galaxies; occurrence, radial extent and scaling relations
- Young, metal-enriched cores in early-type dwarf galaxies in the Virgo cluster based on colour gradients
- Star-forming Dwarf Galaxies in Filamentary Structures around the Virgo Cluster: Probing Chemical Pre-processing in Filament Environments
- Formation of Blue-cored Dwarf Early-type Galaxies in a Cluster Environment: a Kinematical Perspective