Understanding the origin of early-type dwarfs: The spectrophotometric study of CGCG014-074

Abstract

Early-type dwarf galaxies constitute a prevalent population in the central regions of rich groups and clusters in the local Universe. These low-luminosity and low-mass stellar systems play a fundamental role in the assembly of the luminous galaxies observed today, according to the $\Lambda$CDM hierarchical theory. The origin of early-type dwarfs has been linked to the transformation of disk galaxies interacting with the intracluster medium, especially in dense environments. However, the existence of low-luminosity early-type galaxies in low-density environments presents a challenge to this scenario. This study presents a comprehensive photometric and spectroscopic analysis of the early-type dwarf galaxy CGCG014-074 using deep GEMINI+GMOS data, focusing on its peculiarities and evolutionary implications. CGCG014-074 exhibits distinct features, including a rotating inner disk, an extended stellar formation with a quiescent phase since about 2 Gyr ago, and the presence of boxy isophotes. From the kinematic analysis, we confirm CGCG014-074 as a nucleated early-type dwarf galaxy with embedded disk. The study of its stellar population parameters using different methods provides significant insights into the galaxy's evolutionary history. These results show an old and metal-poor nucleus ($\sim 9.3$ Gyr and $[Z/H]\sim -0.84$ dex), while the stellar disk is younger ($\sim 4.4$ Gyr) with a higher metallicity ($[Z/H]\sim -0.40$ dex). These distinctive features collectively position CGCG014-074 as a likely building block galaxy that has evolved passively throughout its history.

11 pages, 8 figures. Accepted to be published in MNRAS

References in corpus (20)

• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• Evolutionary stellar population synthesis with MILES - II. Scaled-solar and α-enhanced models
• Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky Survey. I. On the possible disk nature of bright early-type dwarfs
• The AIMSS Project I: Bridging the Star Cluster - Galaxy Divide
• The Carnegie-Irvine Galaxy Survey. III. The Three-Component Structure of Nearby Elliptical Galaxies
• Evolution of dwarf early-type galaxies I. Spatially resolved stellar populations and internal kinematics of Virgo cluster dE/dS0 galaxies
• The Fornax Deep Survey (FDS) with VST. VI. Optical properties of the dwarf galaxies in the Fornax cluster
• Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-Type Galaxies from the SMAKCED Project III. Rotation versus Pressure Support
• Simulations of the formation and evolution of isolated dwarf galaxies
• Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories
• The Impact of Star Formation Histories on Stellar Mass Estimation: Implications from the Local Group Dwarf Galaxies
• SDSS-IV MaNGA: Faint quenched galaxies I- Sample selection and evidence for environmental quenching
• The SAMI -- Fornax Dwarfs Survey I: Sample, observations and the specific stellar angular momentum of dwarf elliptical galaxies
• On the accretion of a new group of galaxies onto Virgo: I. Internal kinematics of nine in-falling dEs
• The SAMI -- Fornax Dwarfs Survey II: The Stellar Mass Fundamental Plane and the Dark Matter fraction of Dwarf Galaxies
• Formation and evolution of blue compact dwarfs: The origin of their steep rotation curves
• First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
• Field/Isolated lenticular galaxies with high $S_N$ values: the case of NGC 4546 and its globular cluster system
• Luminosity Distribution of Dwarf Elliptical-like Galaxies