Secular evolution in action: central values and radial trends in the stellar populations of boxy bulges

Abstract

We determine central values and radial trends in the stellar populations of the bulges of a sample of 28 edge-on S0-Sb disk galaxies, 22 of which are boxy/peanut-shaped (and therefore barred). Our principal findings are the following. (1) At a given velocity dispersion, the central stellar populations of galaxies with boxy/peanut-shaped bulges are indistinguishable from those of early-type (elliptical and S0) galaxies. Either secular evolution affects stellar populations no differently to monolithic collapse or mergers, or secular evolution is not important in the central regions of these galaxies, despite the fact that they are barred. (2) The radial metallicity gradients of boxy/peanut-shaped bulges are uncorrelated with velocity dispersion and are, on average, shallower than those of unbarred early-type galaxies. This is qualitatively consistent with chemodynamical models of bar formation, in which radial inflow and outflow smears out pre-existing gradients.

MNRAS Letters accepted. 5 pages

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Cited by in corpus (13)

• Galaxy Zoo: Observing Secular Evolution Through Bars
• Metallicity gradients through disk Instability: A simple model for the Milky Way's boxy bulge
• Barlenses and X-shape features compared: different manifestations of Boxy/Peanut bulges
• Observed properties of boxy/peanut/barlens bulges
• SDSS-IV MaNGA: Stellar Population Gradients Within Barred Galaxies
• The stellar populations of the central region of M31
• Dark Matter Trapping by Stellar Bars: The Shadow Bar
• The BaLROG project - II. Quantifying the influence of bars on the stellar populations of nearby galaxies
• Galaxies within galaxies in the TIMER survey: stellar populations of inner bars are scaled replicas of main bars
• Barlenses in the CALIFA survey: combining the photometric and stellar population analysis
• Colors of barlenses: evidence for connecting them to boxy/peanut bulges
• Unravelling stellar populations in the Andromeda Galaxy
• Stellar populations of bulges at low redshift