Extreme [OIII] Emitters at z $\sim$ 0.5

Abstract

We have found a sample of extreme emission-line galaxies (EELGs) with strong [OIII]$\lambda$5007 emission at z $\sim$ 0.5. Using broadband photometric selection and requiring small uncertainties in photometry, we searched the 14th Data Release (DR14) of the Sloan Digital Sky Survey (SDSS) and found 2658 candidates with strong i-band excess (i - z $⩽$ r - i - 0.7). We further obtained 649 SDSS spectra of these objects, and visually identified 22 [OIII] emitters lying at 0.40 $<$ z $<$ 0.63. Having constructed their UV-IR spectral energy distributions (SED) we found that they have fairly blue r-W2 and red W1-W4 colors, indicative of strong warm dust emission. Their rest-frame [OIII]$\lambda$5007 equivalent widths are mostly 200-600 Å, and their high [OIII]$\lambda$5007/H$\beta$ ratios put them at the boundary of star-forming galaxies and AGNs on line ratio classification diagrams. The typical E(B-V) and electron temperature of [OIII] emitters are $\sim$ 0.1-0.3 mag and $\sim$ 10${}^4$ K, respectively. The lowest metallicity of our [OIII] emitters with S/N${}_{[\mathrm{OIII}]\lambda 4363}$ $>$ 3 is 12 + log(O/H) = 7.98${}_{-0.02}^{+0.12}$, with a median value of 8.24${}_{-0.04}^{+0.05}$. Our [OIII] emitters exhibit remarkably high line luminosity - 18/22 have L${}_{[\mathrm{OIII}]\lambda 5007}$ $>$ 5$\times$10${}^{42}$ erg ${\mathrm{s}}^{-1}$ and 5/22 have L${}_{[\mathrm{OIII}]\lambda 5007}$ $>$ 10${}^{43}$ erg ${\mathrm{s}}^{-1}$. Their estimated volume number density at z $\sim$ 0.5 is $\sim$ 2$\times$10${}^{-8}$ Mpc${}^{-3}$, with L${}_{[\mathrm{OIII}]\lambda 5007}$ down to $\sim$ 3$\times$10${}^{42}$ erg ${\mathrm{s}}^{-1}$. The cumulative number fraction distribution of EELGs across different redshifts is indicative of a strong redshift evolution at the bright end of the [OIII] luminosity function.

arXiv comment23 pages, 15 figures, accepted for publication in ApJ

References in corpus (39)

• Planck 2015 results. XIII. Cosmological parameters
• Stellar population synthesis at the resolution of 2003
• Galactic Stellar and Substellar Initial Mass Function
• The Dust Content and Opacity of Actively 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
• The Host Galaxies and Classification of Active Galactic Nuclei
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• 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
• The reversal of the star formation-density relation in the distant universe
• Using Strong Lines to Estimate Abundances in Extragalactic HII Regions and Starburst Galaxies
• A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies
• Analysis of galaxy SEDs from far-UV to far-IR with CIGALE: Studying a SINGS test sample
• The chemical composition of metal-poor emission-line galaxies in the Data Release 3 of the Sloan Digital Sky Survey
• Galaxy Zoo Green Peas: Discovery of A Class of Compact Extremely Star-Forming Galaxies
• The Mass-Metallicity Relation with the Direct Method on Stacked Spectra of SDSS Galaxies
• The Gemini Deep Deep Survey. VII. The Redshift Evolution of the Mass-Metallicity Relation
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• A fundamental plane for field star-forming galaxies
• Clues to the Origin of the Mass-Metallicity Relation: Dependence on Star Formation Rate and Galaxy Size
• 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
• The Origin and Optical Depth of Ionizing Radiation in the "Green Pea" Galaxies
• Very Strong Emission-Line Galaxies in the WISP Survey and Implications for High-Redshift Galaxies
• Physical Properties of Emission-Line Galaxies at z ~ 2 from Near-Infrared Spectroscopy with Magellan FIRE
• The Luminosity Function and Star Formation Rate between Redshifts of 0.07 and 1.47 for Narrow-band Emitters in the Subaru Deep Field
• Ly$\alpha$ profile, dust, and prediction of Ly$\alpha$ escape fraction in Green Pea Galaxies
• The WFC3 Infrared Spectroscopic Parallel (WISP) Survey
• Blueberry galaxies: the lowest mass young starbursts
• The matallicities of star-forming galaxies at intermediate redshifts 0.47 < z < 0.92
• The Metal Abundances across Cosmic Time ($\mathcal{M}\mathcal{A}\mathcal{C}\mathcal{T}$) Survey. II. Evolution of the Mass-Metallicity Relation over 8 Billion Years, using [OIII]$\lambda$4363Å-based Metallicities
• Constructing a WISE High Resolution Galaxy Atlas
• Hubble Space Telescope Grism Spectroscopy of Extreme Starbursts Across Cosmic Time: The Role of Dwarf Galaxies in the Star Formation History of the Universe
• Multi-wavelength study of 14000 star-forming galaxies from the Sloan Digital Sky Survey
• Star-forming galaxies with hot dust emission in the Sloan Digital Sky Survey discovered by the Wide-field Infrared Survey Explorer (WISE)
• Lyman-Break Galaxies at $z\sim 3$ in the Subaru Deep Field: Luminosity Function, Clustering and [OIII] Emission
• The Metal Abundances across Cosmic Time ($\mathcal{M}\mathcal{A}\mathcal{C}\mathcal{T}$) Survey. I. Optical Spectroscopy in the Subaru Deep Field
• Metal-poor dwarf galaxies in the SIGRID galaxy sample. II. The electron temperature-abundance calibration and the parameters that affect it
• Could We Detect Molecular Oxygen in the Atmosphere of a Transiting Extra-Solar Earth-Like Planet?

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