The resolved chemical composition of the starburst dwarf galaxy CGCG007-025: Direct method versus photoionization model fitting

Abstract

This work focuses on the gas chemical composition of CGCG007-025. This compact dwarf is undergoing a galaxy wide star forming burst, whose spatial behaviour has been observed by VLT/MUSE. We present a new line measurement library to treat almost 7800 voxels. The direct method chemical analysis is limited to 484 voxels with good detection of the $[SIII]$6312$\mathring{\mathrm{A}}$ temperature diagnostic line. The recombination fluxes are corrected for stellar absorption via a population synthesis. Additionally, we discuss a new algorithm to fit photoionization models via neural networks. The 8 ionic abundances analyzed show a spatial normal distribution with a $\sigma \sim 0.1dex$, where only half this value can be explained by the uncertainty in the measurements. The oxygen abundance distribution is $12+log(O/H)=7.88\pm 0.11$. The $T_e[SIII]$ and $ne[SII]$ are also normally distributed. However, in the central and brightest region, the $ne[SII]$ is almost thrice the mean galaxy value. This is also reflected in the extinction measurements. The ionization parameter has a distribution of $log(U)=-2.52_{0.19}^{0.17}$. The parameter spatial behaviour agrees with the $S^{2+}/S^{+}$ map. Finally, the discrepancies between the direct method and the photoionization model fitting are discussed. In the latter technique, we find that mixing lines with uneven uncertainty magnitudes can impact the accuracy of the results. In these fittings, we recommend overestimating the minimum flux uncertainty one order below the maximum line flux uncertainty. This provides a better match with the direct method.

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References in corpus (22)

• The James Webb Space Telescope
• The MUSE second-generation VLT instrument
• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• Modelling the nebular emission from primeval to present-day star-forming galaxies
• Deriving model-based T${}_e$-consistent chemical abundances in ionised gaseous nebulae
• exoplanet: Gradient-based probabilistic inference for exoplanet data & other astronomical time series
• Ultraviolet spectra of extreme nearby star-forming regions --- approaching a local reference sample for JWST
• The Millennium Galaxy Catalogue: The connection between close pairs and asymmetry; implications for the galaxy merger rate
• Precision abundance analysis of bright HII galaxies
• The COS Legacy Archive Spectroscopy SurveY (CLASSY) Treasury Atlas
• The temperature and ionization structure of the emitting gas in HII galaxies: Implications for the accuracy of abundance determinations
• Hubble Space Telescope Grism Spectroscopy of Extreme Starbursts Across Cosmic Time: The Role of Dwarf Galaxies in the Star Formation History of the Universe
• A new determination of the primordial helium abundance using the analyses of HII region spectra from SDSS
• Extreme Emission-Line Galaxies in SDSS. I. Empirical and model-based calibrations of chemical abundances
• A Bayesian direct method implementation to fit emission line spectra: Application to the primordial He abundance determination
• CHAOS VII: A Large-Scale Direct Abundance Study in M33
• Evidence of very low metallicity and high ionization state in a strongly lensed, star-forming dwarf galaxy at z=3.417
• About Metallicity Variations in the Local Galactic Interstellar Medium
• On the use of Sulphur as a tracer for abundances in galaxies
• New insights on the nebular emission, ionizing radiation and low metallicity of Green Peas from advanced modelling
• CLASSY V: The impact of aperture effects on the inferred nebular properties of local star-forming galaxies
• Hardness of ionizing radiation fields in MaNGA star-forming galaxies

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