Chemodynamics of Green Pea galaxies -- I. Outflows and turbulence driving the escape of ionising photons and chemical enrichment

Abstract

We investigate the ionised gas kinematics, physical properties and chemical abundances of SDSS$J$142947, a Green Pea galaxy at redshift z$\sim$0.17 with strong, double-peak Ly$\alpha$ emission and indirect evidence of Lyman continuum (LyC) leakage. Using high-dispersion spectroscopy, we perform a multi-component analysis of emission-line profiles. Our model consistently fits all lines as a narrow component with intrinsic velocity dispersion $\sigma \sim$40 km s${}^{-1}$, and two broader blue-shifted components with $\sigma \sim$90 km s${}^{-1}$ and $\sim$250 km s${}^{-1}$. We find electron densities and temperatures, ionisation conditions, and direct O/H and N/O abundances for each component. A highly ionised, metal-poor, young and compact starburst dominates narrow emission, showing evidence of hard radiation fields and elevated N/O. The blue-shifted broader components are consistent with highly turbulent, possibly clumpy ionised gas at the base of a strong photoionised outflow, which accounts for $\gtrsim$50% of the integrated emission-line fluxes. The outflow is dense and metal-enriched compared to the HII regions, with expansion velocities larger than those obtained from UV interstellar absorption lines under standard assumptions. Some of these metals may be able to escape, with outflows loading factors comparable to those found in high-$z$ galaxies of similar SFR/Area. Our findings depict a two-stage starburst picture; hard radiation fields from young star clusters illuminate a turbulent and clumpy ISM that has been eroded by SNe feedback. While UV data suggest an extended Ly$\alpha$ halo with high average HI column density, LyC photons could only escape from SDSS$J$142947 through low HI density channels or filaments in the ISM approaching density-bounded conditions, traced by outflowing gas.

23 pages, 21 figures. Accepted for publication in MNRAS

References in corpus (52)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• The Host Galaxies and Classification of Active Galactic Nuclei
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• The MAPPINGS III Library of Fast Radiative Shock Models
• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• Using Lyman-alpha to detect galaxies that leak Lyman continuum
• Nebular Emission Line Ratios in z~2-3 Star-Forming Galaxies with KBSS-MOSFIRE: Exploring the Impact of Ionization, Excitation, and Nitrogen-to-Oxygen Ratio
• Lyman-alpha spectral properties of five newly discovered Lyman continuum emitters
• Ionized gas outflows and global kinematics of low-z luminous star forming galaxies
• Deriving model-based T${}_e$-consistent chemical abundances in ionised gaseous nebulae
• The Star Formation Main Sequence in the Hubble Space Telescope Frontier Fields
• A Local Clue to the Reionization of the Universe
• The SAMI Galaxy Survey: Shocks and Outflows in a normal star-forming galaxy
• High-precision Photometric Redshifts from Spitzer/IRAC: Extreme [3.6]-[4.5] Colors Identify Galaxies in the Redshift Range z~6.6-6.9
• Q1549-C25: A Clean Source of Lyman-Continuum Emission at $z=3.15$
• The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Content
• Blueberry galaxies: the lowest mass young starbursts
• High star formation rates as the origin of turbulence in early and modern disk galaxies
• X-ray binaries as the origin of nebular HeII emission in low-metallicity star-forming galaxies
• The Nature of Extreme Emission Line Galaxies at z=1-2: Kinematics and Metallicities from Near-Infrared Spectroscopy
• The Generation and Dissipation of Interstellar Turbulence - Results from Large Scale High Resolution Simulations
• Understanding the escape of LyC and Ly$\alpha$ photons from turbulent clouds
• The Sunburst Arc: Direct Lyman α escape observed in the brightest known lensed galaxy
• Excitation properties of galaxies with the highest [OIII]/[OII] ratios: No evidence for massive escape of ionizing photons
• The extended HeII4686-emitting region in IZw18 unveiled: clues for peculiar ionizing sources
• The SAMI Galaxy Survey: Exploring the gas-phase Mass-Metallicity Relation
• The temperature and ionization structure of the emitting gas in HII galaxies: Implications for the accuracy of abundance determinations
• Linking Ly-alpha and Low-Ionization Transitions at Low Optical Depth
• Do galaxies that leak ionizing photons have extreme outflows?
• Gemini GMOS/IFU spectroscopy of NGC 1569 - I: Mapping the properties of a young star cluster and its environment
• Feedback in low-mass galaxies in the early Universe
• What controls the ionized gas turbulent motions in dwarf galaxies?
• From Mirrors to Windows: Lyman-Alpha Radiative Transfer in a Very Clumpy Medium
• Kinematics and Optical Depth in the Green Peas: Suppressed Superwinds in Candidate LyC Emitters
• Hubble Space Telescope Grism Spectroscopy of Extreme Starbursts Across Cosmic Time: The Role of Dwarf Galaxies in the Star Formation History of the Universe
• Discovering extremely compact and metal-poor, star-forming dwarf galaxies out to z ~ 0.9 in the VIMOS Ultra-Deep Survey
• Properties of ionized outflows in MaNGA DR2 galaxies
• Studying the galactic outflow in NGC 1569
• Gas expulsion vs gas retention: what process dominates in young massive clusters?
• Kinematics of gas and stars in the circumnuclear starforming ring of NGC 3351
• The impact of Stellar feedback from velocity-dependent ionised gas maps. -- A MUSE view of Haro 11
• The pressure confined wind of the massive and compact superstar cluster M82-A1
• First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon
• Extreme emission-line galaxies out to z$\sim$1 in zCOSMOS. I. Sample and characterization of global properties
• A GMOS-N IFU study of the central H II region in the blue compact dwarf galaxy NGC 4449: Kinematics, Nebular Metallicity and Star-Formation
• MUSE Illuminates Channels for Lyman Continuum Escape in the Halo of SBS 0335-52E
• The VIMOS Ultra Deep Survey: The role of HI kinematics and HI column density on the escape of Lyalpha photons in star-forming galaxies at 2<z<4
• Kinematics of Extremely Metal-poor Galaxies: Evidence for Stellar Feedback
• On the properties of the interstellar medium in extremely metal-poor blue compact dwarf galaxies: GMOS-IFU spectroscopy and SDSS photometry of the double-knot galaxy HS 2236+1344
• An IFU investigation of possible Lyman continuum escape from Mrk 71/NGC 2366
• High velocity blue-shifted FeII absorption in the dwarf star-forming galaxy PHL293B: Evidence for a wind driven supershell?

Cited by in corpus (30)

• A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z > 6 Quasars
• The Low-Redshift Lyman Continuum Survey. Unveiling the ISM properties of low-$z$ Lyman continuum emitters
• CLASSY IV: Exploring UV diagnostics of the interstellar medium in local high-$z$ analogs at the dawn of the JWST era
• The X-SHOOTER Lyman-$\alpha$ survey at z=2 (XLS-z2) I: What makes a galaxy a Lyman-$\alpha$ emitter?
• CLASSY III: The Properties of Starburst-Driven Warm Ionized Outflows
• The ionising photon production efficiency at z~6 for Lyman-alpha emitters using JEMS and MUSE
• The Low-redshift Lyman-continuum Survey: [S II]-deficiency and the leakage of ionizing radiation
• Reconciling escape fractions and observed line emission in Lyman-continuum-leaking galaxies
• Ubiquitous broad-line emission and the relation between ionized gas outflows and Lyman continuum escape in Green Pea galaxies
• Ionized gas kinematics and chemical abundances of low-mass star-forming galaxies at $z\sim 3$
• The connection between galactic outflows and the escape of ionizing photons
• Inferring the HII region escape fraction of ionizing photons from infrared emission lines in metal-poor star-forming dwarf galaxies
• Emission-line Wings Driven by Lyman Continuum in the Green Pea Analog Mrk 71
• The evolution of the SFR and Sigma-SFR of galaxies in cosmic morning (4 < z < 10)
• The Compact UV Size of Green Pea Galaxies As Local Analogs of High-redshift Ly$\alpha$-Emitters
• A $Li$ne $Me$asuring library for large and complex spectroscopic data sets: Implementation of a virtual observatory for JWST spectra
• New insights on the nebular emission, ionizing radiation and low metallicity of Green Peas from advanced modelling
• SOFIA observations of far-IR fine-structure lines in galaxies to measure metallicity
• Gems of the Galaxy Zoos -- a Wide-Ranging Hubble Space Telescope Gap-Filler Program
• Entrainment of Hot Gas into Cold Streams: The Origin of Excessive Star-formation Rates at Cosmic Noon
• Characterisation of the stellar content of SDSS EELGs through self-consistent spectral modelling
• Physical Origins of Outflowing Cold Clouds in Local Star-forming Dwarf Galaxies
• UM462, a local green pea galaxy analogue under the MUSE magnifying glass
• Unraveling the Kinematics of IZw18: A Detailed Study of Ionized Gas with MEGARA/GTC
• Ionized gas metallicity of the strong [OIII]λ emission-line compact galaxies in the LAMOST survey
• IFUM Integrated Field Spectroscopy of Ten M104 Satellite Galaxy Candidates
• Power-law Emission-line Wings and Radiation-Driven Superwinds in Local Lyman Continuum Emitters
• Obscured and unobscured X-ray AGNs I: Host galaxy properties
• Tracing ionized gas kinematics in Lyman-Break Analogs. Implications for star formation compactness and outflow properties
• Extreme equivalent width-selected low-mass starbursts at $z=4-9$: insights into their role in cosmic reionization