# SDSS-IV MaNGA: Inside-out vs. outside-in quenching in different local environments

## TL;DR

This study uses integral field spectroscopy to classify galaxy quenching modes, revealing that inside-out quenching increases with halo mass and is dominant across environments, while outside-in quenching shows no such dependence.

## Contribution

It introduces non-parametric parameters to classify quenching modes and analyzes their dependence on environment and stellar mass in MaNGA galaxies.

## Key findings

- Inside-out quenching fraction increases with halo mass.
- High stellar mass galaxies show more inside-out quenching.
- Outside-in quenching fraction is independent of halo mass.

## Abstract

The large Integral Field Spectroscopy (IFS) surveys have allowed the classification of ionizing sources of emission lines on sub-kpc scales. In this work, we define two non-parametric parameters, quiescence (f$_{q}$) and its concentration (c$_{q}$), to quantify the strength and the spatial distribution of the quenched areas, respectively, traced by the LI(N)ER regions with low EW(H$\alpha$). With these two measurements, we classify MaNGA galaxies into inside-out and outside-in quenching types according to their locations on the f$_{q}$ vs. c$_{q}$ plane and we measure the fraction of inside-out (outside-in) quenching galaxies as a function of halo mass. We find that the fraction of galaxies showing inside-out quenching increases with halo mass, irrespective of stellar mass or galaxy type (satellites vs. centrals). In addition, high stellar mass galaxies exhibit a greater fraction of inside-out quenching compared to low stellar mass ones in all environments. In contrast, the fraction of outside-in quenching does not depend on halo mass. Our results suggest that morphological quenching may be responsible for the inside-out quenching seen in all environments. On the other hand, the flat dependence of the outside-in quenching on halo mass could be a mixed result of ram-pressure stripping and galaxy mergers. Nevertheless, at a given environment and stellar mass, the fraction of inside-out quenching is systematically greater than that of outside-in quenching, suggesting that inside-out quenching is the dominant quenching mode in all environments.