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We use integral field spectroscopic (IFS) observations from the Gemini NorthMulti-Object Spectrograph (GMOS-N) to study the central H II region in a nearbyblue compact dwarf (BCD) galaxy NGC 4449. The IFS data enable us to explore thevariation of physical and chemical conditions of the star-forming region andthe surrounding gas on spatial scales as small as 5.5 pc. Our kinematicalanalysis shows possible signatures of shock ionisation and shell structures inthe surroundings of the star-forming region. The metallicity maps of theregion, created using direct T$_e$ and indirect strong line methods (R$_{23}$,O3N2 and N2), do not show any chemical variation. From the integrated spectrumof the central H II region, we find a metallicity of 12 + log(O/H) = 7.88 $\pm$0.14 ($\sim$ 0.15$^{+0.06}_{-0.04}$ Z$_{\odot}$) using the direct method.Comparing the central H II region metallicity derived here with those of H IIregions throughout this galaxy from previous studies, we find evidence ofincreasing metallicity with distance from the central nucleus. Such chemicalinhomogeneities can be due to several mechanisms, including gas-loss viasupernova blowout, galactic winds, or metal-poor gas accretion. However, wefind that the localised area of decreased metallicity aligns spatially with thepeak of star-forming activity in the galaxy, suggesting that gas-accretion maybe at play here. Spatially-resolved IFS data for the entire galaxy is requiredto confirm the metallicity inhomogeneity found in this study, and determine itspossible cause.

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