The formation of young B/PS bulges in edge-on barred galaxies

TL;DR

This paper demonstrates through chemodynamical simulations that young stellar populations formed from inflowing gas in barred galaxies can buckle out of the plane, creating a detectable blue boxy/peanut-shaped bulge.

Contribution

It introduces a new mechanism for the formation of young B/PS bulges via vertical instability of gas-born stars in barred galaxies.

Findings

Young B/PS bulges are bluer than surrounding bulges.

Simulations show these bulges buckle out of the plane.

Color maps can detect these young bulges.

Abstract

We report about the fact that the stellar population that is born in the gas inflowing towards the central regions can be vertically unstable leading to a B/PS feature remarkably bluer that the surrounding bulge. Using new chemodynamical simulations we show that this young population does not remain as flat as the gaseous nuclear disc and buckles out of the plane to form a new boxy bulge. We show that such a young B/PS bulge can be detected in colour maps.