O/H-N/O: the curious case of NGC 4670

Abstract

We use integral field spectroscopic (IFS) observations from Gemini North Multi-Object Spectrograph (GMOS-N) of a group of four H II regions and the surrounding gas in the central region of the blue compact dwarf (BCD) galaxy NGC 4670. At spatial scales of $\sim$ 9 pc, we map the spatial distribution of a variety of physical properties of the ionised gas: internal dust attenuation, kinematics, stellar age, star-formation rate, emission line ratios and chemical abundances. The region of study is found to be photoionised. Using the robust direct T${}_e$-method, we estimate metallicity, nitrogen-to-oxygen ratio and helium abundance of the four H II regions. The same parameters are also mapped for the entire region using the HII-CHI-mistry code. We find that log(N/O) is increased in the region where the Wolf-Rayet bump is detected.The region coincides with the continuum region, around which we detect a slight increase in He abundance. We estimate the number of WC4, WN2-4 and WN7-9 stars from the integrated spectrum of WR bump region. We study the relation between log(N/O) and 12 + log(O/H) using the spatially-resolved data of the FOV as well as the integrated data of the H II regions from ten BCDs. We find an unexpected negative trend between N/O and metallicity. Several scenarios are explored to explain this trend, including nitrogen enrichment, and variations in star formation efficiency via chemical evolution models.

arXiv comment24 pages, 25 figures, 7 tables, accepted for publication in MNRAS

References in corpus (91)

• Astropy: A Community Python Package for Astronomy
• Galactic Stellar and Substellar Initial Mass Function
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Global Schmidt Law in Star Forming Galaxies
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• The Host Galaxies of AGN
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• Correcting for the Effects of Interstellar Extinction
• Theoretical Modeling of Starburst Galaxies
• [O III]/[N II] as an Abundance Indicator at High Redshift
• Metallicity Calibrations and the Mass-Metallicity Relation for Star-Forming Galaxies
• A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies
• The Mass-Metallicity Relation at z~2
• AMAZE. I. The evolution of the mass-metallicity relation at z>3
• The Arecibo Legacy Fast ALFA Survey: The alpha.40 HI Source Catalog, its Characteristics and their Impact on the Derivation of the HI Mass Function
• The chemical composition of metal-poor emission-line galaxies in the Data Release 3 of the Sloan Digital Sky Survey
• Primordial Nucleosynthesis in the Precision Cosmology Era
• Galaxy Zoo Green Peas: Discovery of A Class of Compact Extremely Star-Forming Galaxies
• An Analytic Model for the Evolution of the Stellar, Gas, and Metal Content of Galaxies
• Stellar evolution with rotation XI: Wolf-Rayet star populations at different metallicities
• Heavy element abundances in blue compact galaxies
• New light on the search for low metallicity galaxies I. The N2 method
• The 2013 Release of Cloudy
• On The Cosmic Origins Of Carbon And Nitrogen
• The most metal-poor galaxies
• Direct Oxygen Abundances for Low Luminosity LVL Galaxies
• Palomar/Las Campanas Imaging Atlas of Blue Compact Dwarf galaxies: I. Images and integrated photometry
• An Integrated Spectrophotometric Survey of Nearby Star-Forming Galaxies
• SDSS IV MaNGA - Metallicity and nitrogen abundance gradients in local galaxies
• The impact of the nitrogen-to-oxygen ratio on ionized nebulae diagnostics based on [NII] emission lines
• New fully empirical calibrations of strong-line metallicity indicators in star forming galaxies
• Chemical abundances in high-redshift galaxies: A powerful new emission line diagnostic
• The Origin and Optical Depth of Ionizing Radiation in the "Green Pea" Galaxies
• A Compendium of Far-Infrared Line and Continuum Emission for 227 Galaxies Observed by the Infrared Space Observatory
• Galaxies with Wolf-Rayet signatures in the low-redshift Universe - A survey using the Sloan Digital Sky Survey
• Oxygen and Nitrogen in Isolated Dwarf Irregular Galaxies
• Deriving model-based T${}_e$-consistent chemical abundances in ionised gaseous nebulae
• Star formation sustained by gas accretion
• On the oxygen and nitrogen chemical abundances and the evolution of the "green pea" galaxies
• C, N, O Abundances in the Most Metal-Poor Damped Lyman alpha Systems
• z~4 Halpha Emitters in GOODS : Tracing the Dominant Mode for Growth of Galaxies
• Reduced Wolf-Rayet Line Luminosities at Low Metallicity
• IZI: Inferring the Gas Phase Metallicity (Z) and Ionization Parameter (q) of Ionized Nebulae using Bayesian Statistics
• MASSIV: Mass Assembly Survey with SINFONI in VVDS. III. Evidence for positive metallicity gradients in z~1.2 star-forming galaxies
• Nitrogen and oxygen abundances in the Local Universe
• Ionized gaseous nebulae chemical abundance determination using the direct method
• Massive star formation in Wolf-Rayet galaxies. IV: Colours, chemical composition analysis and metallicity-luminosity relations
• The star formation history and metal content of the "Green Peas". New detailed GTC-OSIRIS spectrophotometry of three galaxies
• Abundances in Spiral Galaxies: Evidence for Primary Nitrogen Production
• Precision abundance analysis of bright HII galaxies
• The Nitrogen-to-Oxygen evolution in galaxies: the role of the star formation rate
• Effects of episodic gas infall on the chemical abundances in galaxies
• Localized starbursts in dwarf galaxies produced by impact of low metallicity cosmic gas clouds
• A VLT VIMOS study of the anomalous BCD Mrk 996: mapping the ionised gas kinematics and abundances
• BOND: Bayesian Oxygen and Nitrogen abundance Determinations in giant H II regions using strong and semi-strong lines
• Star-Formation Rates of Local Blue Compact Dwarf Galaxies I: 1.4 GHz and 60 um luminosities
• [O II] line ratios
• The interplay between ionized gas and massive stars in the HII galaxy IIZw70: integral field spectroscopy with PMAS
• The young age of the extremely metal-deficient blue compact dwarf galaxy SBS 1415+437
• Complex gas kinematics in compact, rapidly assembling star-forming galaxies
• The Host in Blue Compact Galaxies: Structural Properties and Scaling Relations
• Dust-to-gas ratio and star formation history of blue compact dwarf galaxies
• Integral field spectroscopy of nitrogen overabundant blue compact dwarf galaxies
• Investigating Nearby Star-Forming Galaxies in the Ultraviolet with HST/COS Spectroscopy. I: Spectral Analysis and Interstellar Abundance Determinations
• Uncovering multiple Wolf-Rayet star-clusters and the ionized ISM in Mrk178: the closest metal-poor Wolf-Rayet HII galaxy
• The Lyman break analogue Haro 11: spatially resolved chemodynamics with VLT FLAMES
• Uncovering Blue Diffuse Dwarf Galaxies
• The ionized gas in the central region of NGC 5253: 2D mapping of the physical and chemical properties
• Spatially resolved integral field spectroscopy of the ionized gas in IZw18
• Piecing together the puzzle of NGC 5253: abundances, kinematics and WR stars
• The ionized gas at the center of IC 10: A possible localized chemical pollution by Wolf-Rayet stars
• A VLT VIMOS integral field spectroscopic study of perturbed blue compact galaxies: UM 420 and UM 462
• Blue diffuse dwarf galaxies: a clearer picture
• Extreme emission-line galaxies out to z$\sim$1 in zCOSMOS. I. Sample and characterization of global properties
• Mapping the starburst in Blue Compact Dwarf Galaxies. PMAS Integral Field Spectroscopy of Mrk 1418
• A blind HI survey in the Ursa Major region
• Spectrophotometric investigations of Blue Compact Dwarf Galaxies: Markarian 35
• The merging dwarf galaxy UM 448: chemodynamics of the ionized gas from VLT integral field spectroscopy
• 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
• High resolution spectroscopy of the BCD galaxy Haro 15: II. Chemodynamics
• Integral field spectroscopy of HII regions in M33
• On the properties of the interstellar medium in extremely metal-poor blue compact dwarf galaxies. A VIMOS-IFU study of the cometary galaxy and Ly $\alpha$ absorber Tol 65
• Gemini GMOS--IFU spectroscopy of the compact HII galaxies Tol 0104-388 and Tol 2146-391: The dependence on the properties of the interstellar medium
• Constraining Stellar Feedback: Shock-ionized Gas in Nearby Starburst Galaxies
• 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
• The nature of the Wolf-Rayet galaxy Mrk 209 from photoionization models
• The Metal Abundances across Cosmic Time ($\mathcal{M}\mathcal{A}\mathcal{C}\mathcal{T}$) Survey. I. Optical Spectroscopy in the Subaru Deep Field
• Mapping Luminous Blue Compact Galaxies with VIRUS-P: morphology, line ratios and kinematics
• Are Wolf-Rayet stars able to pollute the interstellar medium of galaxies? Results from the integral field spectroscopy
• The metallicity evolution of blue compact dwarf galaxies from the intermediate redshift to the local Universe

Cited by in corpus (23)

• De Re Metallica: The cosmic chemical evolution of galaxies
• Metallicity calibrations for diffuse ionised gas and low ionisation emission regions
• 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
• Super star cluster feedback driving ionization, shocks and outflows in the halo of the nearby starburst ESO 338-IG04
• The Gaia-ESO Survey: the N/O abundance ratio in the Milky Way
• Inferring the presence of very massive stars in local star-forming regions
• On the origin of nitrogen at low metallicity
• Exploring Chemical Homogeneity in Dwarf Galaxies: A VLT-MUSE study of JKB 18
• Chemical abundances in the nuclear region of nearby galaxies from the Palomar Survey
• SOFIA observations of far-IR fine-structure lines in galaxies to measure metallicity
• Small-scale chemical abundance analysis in a blue compact dwarf galaxy SBS 1415+437
• The Extraplanar Type II Supernova ASASSN-14jb in the Nearby Edge-on Galaxy ESO 467-G051
• AGN feedback can produce metal enrichment on galaxy scales
• He abundances in disc galaxies -- I. Predictions from cosmological chemodynamical simulations
• Unveiling the nitrogen-rich massive star in the metal-poor galaxy NGC 4068
• UM462, a local green pea galaxy analogue under the MUSE magnifying glass
• Chemical abundances in the dwarf galaxy NGC 4163 based on the nebular and auroral emission lines
• Witnessing a Transformation to Blue-cored Dwarf Early-type Galaxies in Filaments and the Cluster Outskirts: Gas-phase Abundances and Internal Kinematics Perspectives
• What do planetary nebulae and H II regions reveal about the chemical evolution of nearby dwarf galaxies?
• Absorption line abundances in the SMC-like galaxy UGC 5282: evidence for ISM dilution from inflows on kiloparsec scales
• The ionization structure and chemical history in isolated H II regions of dwarf galaxies with IFU I. The Sagittarius Dwarf Irregular Galaxy
• Chemical enrichment in LINERs from MaNGA. I. Tracing Oxygen and Nitrogen Nuclear Abundances in LINERs with Varied Ionizing Sources
• The ionization structure and chemical history in isolated H ii regions of dwarf galaxies with VIMOS/IFU II. The Leo A galaxy