H ii regions and diffuse ionized gas in the AMUSING++ Compilation – I. Catalogue presentation

Abstract

ABSTRACT We present a catalogue of ∼52 000 extragalactic H ii regions and their spectroscopic properties obtained using Integral Field Spectroscopy (IFS) from MUSE observations. The sample analysed in this study contains 678 galaxies within the nearby Universe (0.004 <z < 0.06) covering different morphological types and a wide range of stellar masses (6 < log(M*/M⊙) < 13). Each galaxy was analysed using the pipe3d and pyhiiextractor codes to obtain information of the ionized gas and underlying stellar populations. Specifically, the fluxes, equivalent widths, velocities and velocity dispersions of 30 emission lines covering the wavelength range between λ4750 to λ9300 Å, were extracted and were used to estimate luminosity weighted ages and metallicities of the underlying stellar populations from each H ii region (of the original sample we detect H ii regions in 539 galaxies). In addition, we introduce and apply a novel method and independent of any intrinsic physical property to estimate and decontaminate the contribution of the diffuse ionized gas. Using the final catalogue, we explore the dependence of properties of the H ii regions on different local and global galaxy parameters: (i) Hubble type, (ii) stellar mass, (iii) galactocentric distance, and (iv) the age and metallicity of the underlying/neighbour stellar populations. We confirm known relations between properties of the H ii regions and the underlying stellar populations (in particular, with the age) uncovered using data of lower spatial and spectral resolution. Furthermore, we describe the existence of two main families of diffuse ionized gas different for galaxies host or not of H ii regions.