Estimating Dust Attenuation From Galactic Spectra. III. Radial variations of dust attenuation scaling relations in MaNGA galaxies

TL;DR

This study examines how dust attenuation scaling relations vary radially within galaxies using MaNGA IFS data, revealing significant regional differences and property correlations that inform high-redshift galaxy studies.

Contribution

It provides the first detailed analysis of radial variations in dust attenuation scaling relations in nearby galaxies using integral field spectroscopy data.

Findings

Dust attenuation relations vary significantly from galaxy centers to outer regions.

Different properties dominate correlations with dust attenuation depending on radial distance.

Hα-bright regions show stronger gas attenuation correlations, while Hα-faint regions correlate more with stellar attenuation.

Abstract

We investigate the radial dependence of the scaling relations of dust attenuation in nearby galaxies using integral field spectroscopy (IFS) data from MaNGA. We identify ionized gas regions of kpc sizes from MaNGA galaxies, and for each region we estimate both the stellar attenuation $E(B-V)_{\rm star}$ and gas attenuation $E(B-V)_{\rm gas}$. We then quantify the correlations of 15 regional/global properties with $E(B-V)_{\rm gas}$ and $E(B-V)_{\rm star}$, using both the feature importance obtained with the Random Forest regression technique and the Spearman correlation coefficients. The importance of stellar mass, metallicity and nebular velocity dispersion found previously from SDSS-based studies can be reproduced if our analysis is limited to the central region of galaxies. The scaling relations of both $E(B-V)_{\rm gas}$ and $E(B-V)_{\rm star}$ are found to strongly vary as one goes from the galactic center to outer regions, and from H$\alpha$-bright regions to H$\alpha$-faint regions. For $E(B-V)_{\rm gas}$, [NII]/[SII] is top ranked with a much higher correlation coefficient than any other property at $0<R\lesssim R_e$, while [OIII]/[OII] outperforms [NII]/[SII] as the leading property in the outermost region. For $E(B-V)_{\rm star}$, stellar age shows the strongest correlation with no/weak dependence on radial distance, although $\rm \Sigma_{H\alpha}$ and sSFR present similarly strong correlations with $E(B-V)_{\rm star}$ in the galactic center. We find H$\alpha$-bright regions to generally show stronger correlations with $E(B-V)_{\rm gas}$, while H$\alpha$-faint regions are more strongly correlated with $E(B-V)_{\rm star}$, although depending on individual properties and radial distance. The implications of our results on studies of high-$z$ galaxies are discussed.