Barlenses in the CALIFA survey: combining the photometric and stellar population analysis

TL;DR

This study combines morphological and stellar population analysis of barlenses in CALIFA survey galaxies, revealing their significant contribution to bulge light and their stellar populations' evolution alongside bars.

Contribution

It is the first to integrate morphological and stellar population analysis to study barlenses, highlighting their role in galaxy central mass buildup.

Findings

Barlenses contribute significantly to photometric bulge light.

Barlenses and bars share similar stellar age and metallicity distributions.

Stars in barlenses are accumulated over a prolonged period, concurrent with bar evolution.

Abstract

We investigate barlenses in the Calar Alto Legacy Integral Field Area (CALIFA) survey galaxies, studying their morphologies, stellar populations and metallicities. Multi-component decompositions are made using the Sloan Digital Sky Survey (SDSS) images and making GALFIT models, fitting besides bulges, disks and bars, also barlenses, which are the face-on counterparts of Boxy/Peanut bulges. Similar GALFIT models as were made for the galaxies, were made also for the simulation snap-shots. For the stellar populations and metallicities in the various structure components CALIFA IFU-observations are used. We show that, when present, barlenses account for a significant portion of light of photometric bulges (i.e. the excess light on top of the disks), which highlights the importance of bars in accumulating the central galaxy mass concentrations in the cosmic timescale. Bars and barlenses are found to have similar cumulative stellar age and metallicity distributions. This is the first time that a combined morphological and stellar population analysis is used to study barlenses. We show that their stars are accumulated in a prolonged time period, concurrently with the evolution of the narrow bar.