2D-Galactic chemical evolution: the role of the spiral density wave

TL;DR

This study develops a 2D chemical evolution model for a Milky Way-like galaxy, examining how spiral arms influence azimuthal abundance variations and comparing predictions with recent integral field unit observations.

Contribution

It introduces a 2D chemical evolution code that incorporates spiral density wave effects, providing new insights into azimuthal abundance patterns and star formation in galactic disks.

Findings

Spiral arms affect early stellar and star formation surface densities.

Elemental abundance patterns are less affected by spiral arms at early times.

Current observational uncertainties make differences among models less distinguishable.

Abstract

We present a 2-dimensional chemical evolution code applied to a Milky Way type galaxy, incorporating the role of spiral arms in shaping azimuthal abundance variations, and confront the predicted behaviour with recent observations taken with integral field units. To the usual radial distribution of mass, we add the surface density of the spiral wave and study its effect on star formation and elemental abundances. We compute five different models: one with azimuthal symmetry which depends only on radius, while the other four are subjected to the effect of a spiral density wave. At early times, the imprint of the spiral density wave is carried by both the stellar and star formation surface densities; conversely, the elemental abundance pattern is less affected. At later epochs, however, differences among the models are diluted, becoming almost indistinguishable given current observational uncertainties. At the present time, the largest differences appear in the star formation rate and/or in the outer disc (R$\ge$ 18\,kpc). The predicted azimuthal oxygen abundance patterns for $t \le 2$\,Gyr are in reasonable agreement with recent observations obtained with VLT/MUSE for NGC 6754