Extreme emission-line galaxies out to z$\sim$1 in zCOSMOS. I. Sample and characterization of global properties

Abstract

We present a thorough characterization of a large sample of 183 extreme emission-line galaxies (EELGs) at redshift 0.11 < z < 0.93 selected from the 20k zCOSMOS Bright Survey because of their unusually large emission line equivalent widths. We use multiwavelength COSMOS photometry, HST-ACS I-band imaging and optical zCOSMOS spectroscopy to derive the main global properties of EELGs, such as sizes, masses, SFRs, reliable metallicities from both "direct" and "strong-line" methods. The EELGs are compact (R_50 ~ 1.3 kpc), low-mass (log(M*/Msol)~7-10) galaxies forming stars at unusually high specific SFR (log(sSFR/yr) up to ~ -7) compared to main sequence SFGs of the same stellar mass and redshift. At UV wavelengths, the EELGs are luminous and show high surface brightness and include strong Ly$\alpha$ emitters, as revealed by GALEX spectroscopy. We show that zCOSMOS EELGs are high-ionization, low-metallicity systems, with median 12+log(O/H)=8.16, including a handful of extremely metal-deficient galaxies (<10% solar). While ~80% of the EELGs show non-axisymmetric morphologies, including clumpy and tadpole galaxies, we find that ~29% of them show additional low surface-brightness features, which strongly suggest recent or ongoing interactions. As star-forming dwarfs in the local Universe, EELGs are most often found in relative isolation. While only very few EELGs belong to compact groups, almost one third of them are found in spectroscopically confirmed loose pairs or triplets. We conclude that EELGs are galaxies caught in a transient and probably early period of their evolution, where they are efficiently building-up a significant fraction of their present-day stellar mass in an ongoing galaxy-wide starburst. Therefore, the EELGs constitute an ideal benchmark for comparison studies between low- and high-redshift low-mass star-forming galaxies.

arXiv commentAccepted in A&A. Final replacement to match the version in press. It includes a minor change in the title and a new figure

References in corpus (77)

• Stellar population synthesis at the resolution of 2003
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• The Global Schmidt Law in Star Forming Galaxies
• The Host Galaxies of AGN
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• Star Formation in the Milky Way and Nearby Galaxies
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The Cosmic Evolution Survey (COSMOS) -- Overview
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• Evolutionary population synthesis: models, analysis of the ingredients and application to high-z galaxies
• The reversal of the star formation-density relation in the distant universe
• Metallicity Calibrations and the Mass-Metallicity Relation for Star-Forming Galaxies
• Dust Absorption And The Ultraviolet Luminosity Density At z \approx 3 As Calibrated By Local Starburst Galaxies
• zCOSMOS: A Large VLT/VIMOS redshift survey covering 0 < z < 3 in the COSMOS field
• The 'Forbidden' Abundance of Oxygen in the Sun
• The First Data Release of the Sloan Digital Sky Survey
• The Relationship Between Stellar Light Distributions of Galaxies and their Formation Histories
• A New Non-Parametric Approach to Galaxy Morphological Classification
• The First Release COSMOS Optical and Near-IR Data and Catalog
• The Rest Frame Optical Spectra of Lyman Break Galaxies: Star Formation, Extinction, Abundances, and Kinematics
• The COSMOS Survey: Hubble Space Telescope / Advanced Camera for Surveys (HST/ACS) Observations and Data Processing
• The Spitzer Legacy Survey of the HST-ACS 2 sq. deg. COSMOS Field: survey strategy and first analysis
• The transition from Population III to normal galaxies: Ly-a and HeII 1640 emission and the ionising properties of high redshift starburst galaxies
• Nebular Emission from Star-Forming Galaxies
• New light on the search for low metallicity galaxies I. The N2 method
• The Chandra COSMOS Survey, I: Overview and Point Source Catalog
• The Cosmic Evolution Survey (COSMOS): Subaru Observations of the HST COSMOS Field
• Ionization State of Inter-Stellar Medium in Galaxies: Evolution, SFR-M_star-Z Dependence, and Ionizing Photon Escape
• The XMM-Newton wide-field survey in the COSMOS field: I. Survey description
• The VLA-COSMOS Survey: II. Source Catalog of the Large Project
• The impact of the nitrogen-to-oxygen ratio on ionized nebulae diagnostics based on [NII] emission lines
• UV star-formation rates of GRB host galaxies
• Stellar masses from the CANDELS survey: the GOODS-South and UDS fields
• Gas accretion as the origin of chemical abundance gradients in distant galaxies
• The Origin and Optical Depth of Ionizing Radiation in the "Green Pea" Galaxies
• The COSMOS-WIRCam near-infrared imaging survey: I: BzK selected passive and star forming galaxy candidates at z>1.4
• The Nature of Compact Galaxies in the Hubble Deep Field (II): Spectroscopic Properties and Implications for the Evolution of the Star Formation Rate Density of the Universe
• A New Diagnostic of Active Galactic Nuclei: Revealing Highly-Absorbed Systems at Redshift>0.3
• Spectroscopy of superluminous supernova host galaxies. A preference of hydrogen-poor events for extreme emission line galaxies
• Deriving model-based T${}_e$-consistent chemical abundances in ionised gaseous nebulae
• Very Strong Emission-Line Galaxies in the WISP Survey and Implications for High-Redshift Galaxies
• Tracking the impact of environment on the Galaxy Stellar Mass Function up to z~1 in the 10k zCOSMOS sample
• Eliminating Error in the Chemical Abundance Scale for Extragalactic HII Regions
• The Luminosity-Metallicity relation in the local universe from the 2dF Galaxy Redshift Survey
• Strong Emission Line HII Galaxies in the Sloan Digital Sky Survey. I. Catalog of DR1 Objects with Oxygen Abundances from Te easurements
• The zCOSMOS Redshift Survey: the role of environment and stellar mass in shaping the rise of the morphology-density relation from z~1
• Extreme Emission Line Galaxies in CANDELS: Broad-Band Selected, Star-Bursting Dwarf Galaxies at z>1
• Line temperatures and elemental abundances in HII galaxies
• A robust morphological classification of high-redshift galaxies using support vector machines on seeing limited images. I Method description
• HST morphologies of local Lyman break galaxy analogs I: Evidence for starbursts triggered by merging
• An optical group catalogue to z = 1 from the zCOSMOS 10k sample
• First Spectroscopic Evidence for High Ionization State and Low Oxygen Abundance in Lya Emitters
• Precision abundance analysis of bright HII galaxies
• Low-Redshift Ly-alpha Selected Galaxies from GALEX Spectroscopy: A Comparison with Both UV-Continuum Selected Galaxies and High-Redshift Ly-alpha Emitters
• The cosmic evolution of oxygen and nitrogen abundances in star-forming galaxies over the past 10 Gyrs
• The Nitrogen-to-Oxygen evolution in galaxies: the role of the star formation rate
• AEGIS: Demographics of X-ray and Optically Selected AGNs
• Systematic search for extremely metal poor galaxies in the Sloan Digital Sky Survey
• Lyα Emission from High Redshift Sources in COSMOS
• The environment of HII galaxies
• On the importance of using appropriate spectral models to derive physical properties of galaxies at 0.7<z<2.8
• HeII emitters in the VIMOS VLT Deep Survey: PopIII star formation or peculiar stellar populations in galaxies at 2<z<4.6?
• The physical properties of Lyalpha emitting galaxies: not just primeval galaxies?
• "Direct" Gas-phase Metallicities, Stellar Properties, and Local Environments of Emission-line Galaxies at Redshift below 0.90
• A CANDELS WFC3 Grism Study of Emission-Line Galaxies at z~2: A Mix of Nuclear Activity and Low-Metallicity Star Formation
• When are extremely metal-deficient galaxies extremely metal-deficient?
• The metallicity evolution of low mass galaxies: New constraints at intermediate redshift
• Confirmation of Small Dynamical and Stellar Masses for Extreme Emission Line Galaxies at z~2
• The DEEP2 Galaxy Redshift Survey: Discovery of Luminous, Metal-poor, Sta r-forming Galaxies at Redshifts z~0.7
• The ages, masses and star-formation rates of spectroscopically confirmed z~6 galaxies in CANDELS
• Local Tadpole Galaxies
• Tadpole Galaxies in the Hubble Ultra Deep Field
• Evidence of very low metallicity and high ionization state in a strongly lensed, star-forming dwarf galaxy at z=3.417
• Metallicities of Emission-Line Galaxies from HST ACS PEARS and HST WFC3 ERS Grism Spectroscopy at 0.6 < z < 2.4
• Thermal Emission from HII Galaxies: Discovering the Youngest Systems
• Dissection of Halpha Emitters : Low-z Analogs of z>4 Star-Forming Galaxies
• Emission-Line Galaxy Surveys as Probes of the Spatial Distribution of Dwarf Galaxies. I. The University of Michigan Survey

Cited by in corpus (24)

• De Re Metallica: The cosmic chemical evolution of galaxies
• Ultraviolet spectra of extreme nearby star-forming regions --- approaching a local reference sample for JWST
• Cosmic evolution and metal aversion in super-luminous supernova host galaxies
• Ionized gaseous nebulae chemical abundance determination using the direct method
• The CALYMHA survey: Ly$\alpha$ escape fraction and its dependence on galaxy properties at $z=2.23$
• MMT Spectroscopy of Lyman-alpha at z$\simeq$7: Evidence for Accelerated Reionization Around Massive Galaxies
• The NIRVANDELS Survey: a robust detection of $\alpha$-enhancement in star-forming galaxies at $z\simeq 3.4$
• Peering through the holes: the far UV color of star-forming galaxies at z~3-4 and the escaping fraction of ionizing radiation
• A Low Lyman Continuum Escape Fraction of $<10\%$ for Extreme [OIII] Emitters in an Overdensity at z$\sim 3.5$
• Long-rising Type II supernovae from PTF and CCCP
• Lyman-alpha spectroscopy of extreme [OIII] emitting galaxies at $z\simeq 2-3$: Implications for Ly$\alpha$ visibility and LyC leakage at $z>6$
• Extreme Emission-Line Galaxies in SDSS. I. Empirical and model-based calibrations of chemical abundances
• Chemodynamics of Green Pea galaxies -- I. Outflows and turbulence driving the escape of ionising photons and chemical enrichment
• O/H-N/O: the curious case of NGC 4670
• Direct T${}_e$ metallicity calibration of R23 in strong line emitters
• MUSE integral-field spectroscopy towards the Frontier Fields cluster Abell S1063: II. Properties of low luminosity Lyman alpha emitters at z>3
• Integral Field Spectroscopy of Green Peas (I): Disentangling disk-like, turbulence and strong outflow kinematics in SDSSJ083843.63+385350.5
• Lyman Continuum Escape Fraction from Low-mass Starbursts at z=1.3
• MOSEL: Strong [OIII]5007 Å Emitting Galaxies at (3<z<4) from the ZFOURGE Survey
• Physical Properties of Local Star-Forming Analogues to z~5 Lyman Break Galaxies
• Spatially resolved analysis of Superluminous Supernovae PTF~11hrq and PTF~12dam host galaxies
• Star-forming galaxies at low-redshift in the SHARDS survey
• The Stellar Population of Metal-Poor Galaxies at z $\approx$ 0.8 and the Evolution of the Mass-Metallicity Relation
• Analogs of primeval galaxies two billion years after the Big Bang