Leonessa: An Extremely Metal-poor Galaxy Undergoing Secular Chemical Evolution

Abstract

Extremely metal-poor (XMP) galaxies are systems with gas-phase oxygen abundances below $\sim$5% Solar metallicity (12+log(O/H)$\le$7.35). These galaxies populate the metal-poor end of the mass-metallicity and luminosity-metallicity relations (MZR and LZR, respectively). Recent studies have found XMP galaxies in the nearby Universe to be outliers on the LZR, where they show enhanced luminosities relative to other galaxies of similar gas-phase oxygen abundance. Here, we present a study of the recently discovered XMP galaxy Leonessa and characterize the system's properties using new imaging from the Hubble Space Telescope and spectra from the Green Bank Telescope and Hobby-Eberly Telescope. We use these observations to measure a tip of the red giant branch (TRGB) distance (15.86$\pm$0.78 Mpc) to Leonessa, the HI gas mass, the gas-phase oxygen abundance, and N/O ratio. We find Leonessa is an isolated, gas rich (gas fraction $\mu$=0.69), low-mass (log(M${}_{\star }$/M${}_{\odot }$)=6.12$\pm$0.08), XMP (12+log(O/H)=7.32$\pm$0.04), star-forming galaxy at a distance of 15.86$\pm$0.78 Mpc. Our measurements show that Leonessa agrees with the MZR, but disagrees with the LZR; we conclude the LZR offset is due to recent star formation enhancing the system's luminosity. To investigate possible chemical evolution pathways for nearby XMP galaxies we also compile a comparison sample of 150 dwarf galaxies (53 XMP systems) taken from the literature with gas-phase metallicity measurements based on the direct method. We find evidence for an anti-correlation between gas-phase oxygen abundance and HI gas-to-stellar mass ratios. We posit Leonessa is undergoing a chemical evolution pathway typical of field dwarf galaxies.

29 pages, 8 figures, 3 tables. This manuscript has been accepted for publication by the ApJ. DOI: 10.3847/1538-4357/adf84b

References in corpus (125)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Astropy: A Community Python Package for Astronomy
• Stellar population synthesis at the resolution of 2003
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• The Optical and Near-Infrared Properties of Galaxies: I. Luminosity and Stellar Mass Functions
• How Do Galaxies Get Their Gas?
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• WFPC2 Stellar Photometry with HSTphot
• The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
• The chemical make-up of the Sun: A 2020 vision
• Cosmicflows-2: The Data
• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• The chemical composition of metal-poor emission-line galaxies in the Data Release 3 of the Sloan Digital Sky Survey
• Stellar evolution with rotation VIII: Models at Z = 10^{-5} and CNO yields for early galactic evolution
• Measurements of the Hubble Constant: Tensions in Perspective
• A Remarkably Luminous Galaxy at z=11.1 Measured with Hubble Space Telescope Grism Spectroscopy
• The Arecibo Legacy Fast ALFA Survey: The ALFALFA Extragalactic HI Source Catalog
• The Spitzer Local Volume Legacy: Survey Description and Infrared Photometry
• A Digital Archive of HI 21 cm Line Spectra of Optically-targeted Galaxies
• On Extending the Mass-Metallicity Relation of Galaxies by 2.5 Decades in Stellar Mass
• On The Cosmic Origins Of Carbon And Nitrogen
• Supernova feedback efficiency and mass loading in the starburst and galactic superwind exemplar M82
• Direct Oxygen Abundances for Low Luminosity LVL Galaxies
• Tip of the Red Giant Branch Distances. II. Zero-Point Calibration
• The Metallicity-Luminosity Relation, Effective Yields, and Metal Loss in Spiral and Irregular Galaxies
• The Role of Cold Flows in the Assembly of Galaxy Disks
• The SBF Survey of Galaxy Distances. II. Local and Large-Scale Flows
• The Metallicity of Galaxy Disks: Infall versus Outflow
• Stellar Masses and SFRs for 1M Galaxies from SDSS and WISE
• The Baryon Content of Extremely Low Mass Dwarf Galaxies
• J1154+2443: a low-redshift compact star-forming galaxy with a 46 per cent leakage of Lyman continuum photons
• The Panchromatic Hubble Andromeda Treasury X. Ultraviolet to Infrared Photometry of 117 Million Equidistant Stars
• Oxygen and Nitrogen in Isolated Dwarf Irregular Galaxies
• Constraints on star-formation driven galaxy winds from the mass-metallicity relation at z=0
• The Aspen--Amsterdam Void Finder Comparison Project
• GLADE: A Galaxy Catalogue for Multi-Messenger Searches in the Advanced Gravitational-Wave Detector Era
• Leo A: A Late-Blooming Survivor of the Epoch of Reionization in the Local Group
• Tip of the Red Giant Branch Distances. I. Optimization of a Maximum Likelihood Algorithm
• A Database of Cepheid Distance Moduli and TRGB, GCLF, PNLF and SBF Data Useful for Distance Determinations
• The Nature of Starbursts : II. The Duration of Starbursts in Dwarf Galaxies
• The HETDEX Instrumentation: Hobby-Eberly Telescope Wide Field Upgrade and VIRUS
• The Chemical Evolution of Carbon, Nitrogen, and Oxygen in Metal-Poor Dwarf Galaxies
• CHAOS IV: Gas-Phase Abundance Trends From The First Four CHAOS Galaxies
• Cosmicflows-4
• ALFALFA Discovery of the Nearby Gas-Rich Dwarf Galaxy Leo~P. III. An Extremely Metal Deficient Galaxy
• Leo P: An Unquenched Very Low-Mass Galaxy
• Nitrogen and oxygen abundances in the Local Universe
• Metal-enriched galactic outflows shape the mass-metallicity relationship
• Blueberry galaxies: the lowest mass young starbursts
• Is molecular gas necessary for star formation?
• The COS Legacy Archive Spectroscopy SurveY (CLASSY) Treasury Atlas
• J0811+4730: the most metal-poor star-forming dwarf galaxy known
• Hunting for extremely metal-poor emission-line galaxies in the Sloan Digital Sky Survey: MMT and 3.5m APO observations
• Extremely metal-poor star-forming galaxies. New detections and general morphological and photometric properties
• The triggering of starbursts in low-mass galaxies
• Galactic Winds in Low-Mass Galaxies
• The Extragalactic Distance Database: All Digital HI Profile Catalog
• A physically motivated definition for the size of galaxies in an era of ultra-deep imaging
• The Tip of the Red Giant Branch Distances to Type Ia Supernova Host Galaxies. IV. Color Dependence and Zero-Point Calibration
• Only the Lonely: H I Imaging of Void Galaxies
• The resolved stellar populations in the LEGUS galaxies
• The Spatial Homogeneity of Nebular and Stellar Oxygen Abundances in the Local Group Dwarf Irregular Galaxy NGC 6822
• Systematic search for extremely metal poor galaxies in the Sloan Digital Sky Survey
• Dynamics of Starbursting Dwarf Galaxies: I Zw 18
• VLT spectroscopy of low-metallicity emission-line galaxies: abundance patterns and abundance discrepancies
• Spatially-unresolved SED fitting can underestimate galaxy masses: a solution to the missing mass problem
• Spitzer Local Volume Legacy (LVL) SEDs and Physical Properties
• "Direct" Gas-phase Metallicities, Stellar Properties, and Local Environments of Emission-line Galaxies at Redshift below 0.90
• Extremely Metal-Poor Representatives Explored by the Subaru Survey (EMPRESS). I. A Successful Machine Learning Selection of Metal-Poor Galaxies and the Discovery of a Galaxy with M*<10^6 M_sun and 0.016 Z_sun
• Missing Stellar Mass in SED Fitting: Spatially Unresolved Photometry can Underestimate Galaxy Masses
• The Carnegie-Chicago Hubble Program. II. The Distance to IC 1613: The Tip of the Red Giant Branch and RR Lyrae Period-Luminosity Relations
• HI and star formation in the most metal-deficient galaxies
• The ALFALFA-SDSS Galaxy Catalog
• Observational constraints on stellar feedback in dwarf galaxies
• Search for Extremely Metal-poor Galaxies in the Sloan Digital Sky Survey (II): high electron temperature objects
• When are extremely metal-deficient galaxies extremely metal-deficient?
• The Star Formation History of the very metal poor BCD IZw18 from HST/ACS data
• Dynamics of Starbursting Dwarf Galaxies. II. UGC 4483
• Virgo Filaments I: Processing of gas in cosmological filaments around the Virgo cluster
• Evolution of N/O ratios in galaxies from cosmological hydrodynamical simulations
• The Carnegie-Chicago Hubble Program. VII. The Distance to M101 via the Optical Tip of the Red Giant Branch Method
• Searching for metal-deficient emission-line galaxy candidates: the final sample of the SDSS DR12 galaxies
• The dust content of the most metal-poor star-forming galaxies
• NIBLES - an HI census of stellar mass selected SDSS galaxies: I. The Nançay HI survey
• Low-redshift lowest-metallicity star-forming galaxies in the SDSS DR14
• Extremely Metal-Poor Galaxies: The HI Content
• Leo P: How Many Metals can a Very Low-Mass, Isolated Galaxy Retain?
• EMPRESS. II. Highly Fe-Enriched Metal-poor Galaxies with $\sim 1.0$ (Fe/O)${}_{\odot }$ and $0.02$ (O/H)${}_{\odot }$ : Possible Traces of Super Massive ($>300M_{\odot }$) Stars in Early Galaxies
• The Leoncino Dwarf Galaxy: Exploring the Low-Metallicity End of the Luminosity-Metallicity and Mass-Metallcity Relations
• J2229+2725: an extremely low-metallicity dwarf compact star-forming galaxy with an exceptionally high [OIII]5007/[OII]3727 flux ratio of 53
• Extremely Metal-Poor Galaxies: The Environment
• LRS2: the new facility low resolution integral field spectrograph for the Hobby-Eberly Telescope
• The Little Cub: Discovery of an Extremely Metal-Poor Star-Forming Galaxy in the Local Universe
• Environmental Effects on the Metal Enrichment of Low Mass Galaxies in Nearby Clusters
• Distance Determinations to SHIELD Galaxies from HST Imaging
• MMT Extremely Metal Poor Galaxy Survey I. An Efficient Technique to Identify Metal Poor Galaxies
• Extragalactic archaeology with the C, N, and O chemical abundances
• The metallicity of void dwarf galaxies
• HI studies of eXtremely Metal Deficient galaxies - II: GMRT observations of SBS 1129+576
• Photometric identification and MMT spectroscopy of new extremely metal-poor galaxies: towards a better understanding of young stellar populations at low metallicity
• Galactic Outflows, Star Formation Histories, and Timescales in Starburst Dwarf Galaxies from STARBIRDS
• Statistical Analysis of H I Profile Asymmetry and Shape for Nearby Galaxies
• Void galaxies in the nearby Universe. I. Sample description
• Study of galaxies in the Eridanus void. Sample and oxygen abundances
• XMP gas-rich dwarfs in nearby voids: results of BTA spectroscopy
• CO-CAVITY pilot survey: Molecular gas and star formation in void galaxies
• On the influence of the environment on galactic chemical abundances
• The HI content of extremely metal-deficient blue compact dwarf galaxies
• Cosmological evolution of the Nitrogen abundance
• The Enigmatic (Almost) Dark Galaxy Coma P: Distance Measurement and Stellar Populations from HST Imaging
• New candidates for extremely metal-poor emission-line galaxies in the SDSS/BOSS DR10
• A census of OBe stars in nearby metal-poor dwarf galaxies reveals a high fraction of extreme rotators
• A complete spectroscopic catalogue of local galaxies in the Northern spring sky -- Gas properties and nuclear activity in different environments
• Properties of the most metal-poor gas-rich LSB dwarf galaxies SDSS J0015+0104 and J2354-0005 residing in the Eridanus void
• Optical spectroscopy of the extremely metal-deficient star-forming galaxy HSC J1631+4426: a test of the strong-line method
• EMPRESS. XI. SDSS and JWST Search for Local and z~4-5 Extremely Metal-Poor Galaxies (EMPGs): Clustering and Chemical Properties of Local EMPGs
• Diffuse HI Disks in Isolated Galaxies
• Influence of the Void Environment on Chemical Abundances in Dwarf Galaxies and Implications for Connecting Star Formation and Halo Mass
• XMP gas-rich dwarfs in Nearby Voids: candidate selection
• DDO68 C: the actual appearance of a ghost satellite dwarf through adaptive optics at the Large Binocular Telescope
• Searches for Extremely Metal Poor Galaxies using ALFALFA-selected Dwarf Galaxies

Cited by in corpus (1)

• GLIMPSE-D: Metallicity Decline in Faint Galaxies: Implications for [O III]+Hb Luminosity Function and Reionisation Budget