EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies

Abstract

We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of $0.015-0.195Z_{\odot }$ and low stellar masses of $10^4-10^8{M}_{\odot }$ in the local universe. We conduct deep optical integral-field spectroscopy (IFS) for the low-mass EMPGs with the medium high resolution ($R=7500$) grism of the 8m-Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate H$\alpha$ emission of the EMPGs. Exploiting the resolution high enough for the low-mass galaxies, we derive gas dynamics with the H$\alpha$ lines by the fitting of 3-dimensional disk models. We obtain an average maximum rotation velocity ($v_{\mathrm{rot}}$) of $15\pm 3\mathrm{km}{\mathrm{s}}^{-1}$ and an average intrinsic velocity dispersion (${\sigma }_0$) of $27\pm 10\mathrm{km}{\mathrm{s}}^{-1}$ for 15 spatially resolved EMPGs out of the 33 EMPGs, and find that all of the 15 EMPGs have $v_{\mathrm{rot}}/{\sigma }_0<1$ suggesting dispersion dominated systems. There is a clear decreasing trend of $v_{\mathrm{rot}}/{\sigma }_0$ with the decreasing stellar mass and metallicity. We derive the gas mass fraction ($f_{\mathrm{gas}}$) for all of the 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These $v_{\mathrm{rot}}/{\sigma }_0$ and $f_{\mathrm{gas}}$ trends should be compared with young high-$z$ galaxies observed by the forthcoming JWST IFS programs to understand the physical origins of the EMPGs in the local universe.

arXiv comment18 pages, 9 figures, accepted for publication in ApJ

References in corpus (64)

• Astropy: A Community Python Package for Astronomy
• Galactic Stellar and Substellar Initial Mass Function
• The Structure of Cold Dark Matter Halos
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Global Schmidt Law in Star Forming Galaxies
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Detailed Structural Decomposition of Galaxy Images
• Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
• The SINS survey: SINFONI Integral Field Spectroscopy of z ~ 2 Star-forming Galaxies
• The chemical make-up of the Sun: A 2020 vision
• The SINS survey of z~2 galaxy kinematics: properties of the giant star forming clumps
• Second Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• Inefficient Star Formation In Extremely Metal Poor Galaxies
• High-Ionization Emission in Metal-Deficient Blue Compact Dwarf Galaxies
• A dynamically cold disk galaxy in the early Universe
• Strong Emission Line HII Galaxies in the Sloan Digital Sky Survey. I. Catalog of DR1 Objects with Oxygen Abundances from Te easurements
• Dynamical properties of z $\sim 4.5$ dusty star-forming galaxies and their connection with local early type galaxies
• ALFALFA Discovery of the Nearby Gas-Rich Dwarf Galaxy Leo~P. III. An Extremely Metal Deficient Galaxy
• I Zw 18 revisited with HST/ACS and Cepheids: New Distance and Age
• DYNAMO I: A Sample of Ha-Luminous Galaxies with Resolved Kinematics
• Leo P: An Unquenched Very Low-Mass Galaxy
• Rotation Curves in z~1-2 Star-Forming Disks: Evidence for Cored Dark Matter Distributions
• 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
• MMT observations of new extremely metal-poor emission-line galaxies in the Sloan Digital Sky Survey
• EMPRESS. V. Metallicity Diagnostics of Galaxies over 12+log(O/H)=~6.9-8.9 Established by a Local Galaxy Census: Preparing for JWST Spectroscopy
• EMPRESS. VIII. A New Determination of Primordial He Abundance with Extremely Metal-Poor Galaxies: A Suggestion of the Lepton Asymmetry and Implications for the Hubble Tension
• Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey
• SBS 0335-052E+W: deep VLT/FORS+UVES spectroscopy of the pair of the lowest-metallicity blue compact dwarf galaxies
• The detection of [Ne v] emission in five blue compact dwarf galaxies
• What Causes The Formation of Disks and End of Bursty Star Formation?
• ALFALFA Discovery of the Most Metal-Poor Gas-Rich Galaxy Known: AGC 198691
• Systematic search for extremely metal poor galaxies in the Sloan Digital Sky Survey
• Diverse properties of Ly-alpha emission in low-redshift compact star-forming galaxies with extremely high [OIII]/[OII] ratios
• Metallicity inhomogeneities in local star-forming galaxies as sign of recent metal-poor gas accretion
• 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
• LBT observations of compact star-forming galaxies with extremely high [OIII]/[OII] flux ratios: HeI emission-line ratios as diagnostics of Lyman continuum leakage
• A mass threshold for galactic gas discs by spin flips
• Search for Extremely Metal-poor Galaxies in the Sloan Digital Sky Survey (II): high electron temperature objects
• ALFALFA Discovery of the Nearby Gas-rich Dwarf Galaxy Leo P. V. Neutral Gas Dynamics and Kinematics
• The Star Formation History of the very metal poor BCD IZw18 from HST/ACS data
• Larson's scaling laws, and the gravitational instability of clumpy discs at high redshift
• From lenticulars to blue compact dwarfs: the stellar mass fraction is regulated by disc gravitational instability
• The structure of gravitationally unstable gas-rich disk galaxies
• From massive spirals to dwarf irregulars: a new set of tight scaling relations for cold gas and stars driven by disc gravitational instability
• The He abundance in the metal-deficient blue compact dwarf galaxies Tol 1214-277 and Tol 65
• SBS 0335-052 E and W: implications of new broad-band and H-alpha photometry
• J1234+3901: an extremely metal-deficient compact star-forming dwarf galaxy at redshift 0.133
• Infrared Properties of Star Forming Dwarf Galaxies: I. Dwarf Irregular Galaxies in the Local Volume
• Extremely Metal-Poor Galaxies: The HI Content
• EMPRESS. IV. Extremely Metal-Poor Galaxies (EMPGs) Including Very Low-Mass Primordial Systems with M*=10^4--10^5 M_sun and 2--3% (O/H)_sun: High (Fe/O) Suggestive of Metal Enrichment by Hypernovae/Pair-Instability Supernovae
• 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
• J2229+2725: an extremely low-metallicity dwarf compact star-forming galaxy with an exceptionally high [OIII]5007/[OII]3727 flux ratio of 53
• The Little Cub: Discovery of an Extremely Metal-Poor Star-Forming Galaxy in the Local Universe
• Blue diffuse dwarf galaxies: a clearer picture
• Photometric identification and MMT spectroscopy of new extremely metal-poor galaxies: towards a better understanding of young stellar populations at low metallicity
• EMPRESS. VII. Ionizing Spectrum Shapes of Extremely Metal-Poor Galaxies: Uncovering the Origins of Strong HeII and the Impact on Cosmic Reionization
• EMPRESS. VI. Outflows Investigated in Low-Mass Galaxies with $M_{\ast }=10^4-10^7{M}_{\odot }$: Weak Feedback in Low-Mass Galaxies?
• SH$\alpha$DE: Survey description and mass-kinematics scaling relations for dwarf galaxies
• Possible Systematic Rotation in the Mature Stellar Population of a $z=9.1$ Galaxy
• Star formation in the nearby dwarf galaxy DDO 53: interplay between gas accretion and stellar feedback
• EMPRESS. III. Morphology, Stellar Population, and Dynamics of Extremely Metal Poor Galaxies (EMPGs): Are EMPGs Local Analogs of High-$z$ Young Galaxies?
• The Stellar Kinematics of Void Dwarf Galaxies Using KCWI
• Optical spectroscopy of the extremely metal-deficient star-forming galaxy HSC J1631+4426: a test of the strong-line method

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