The frequency and stellar-mass dependence of boxy/peanut-shaped bulges in barred galaxies. Issue 2 (14th March 2017)

• Record Type: Journal Article
• Authors: Erwin, Peter; Debattista, Victor P.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 468:Issue 2(2017)
• Page Start: 2058
• Page End: 2080
• Publication Date: 2017-03-14
• Subjects: galaxies: bulges -- galaxies: elliptical and lenticular, cD -- galaxies: spiral -- galaxies: structure; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stx620
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: From a sample of 84 local barred, moderately inclined disc galaxies, we determine the fraction that hosts boxy or peanut-shaped (B/P) bulges (the vertically thickened inner parts of bars). We find that the frequency of B/P bulges in barred galaxies is a very strong function of stellar mass: 79 per cent of the bars in galaxies with log ( M ⋆ /M⊙ )w ≳ 10.4 have B/P bulges, while only 12 per cent of those in lower mass galaxies do. (We find a similar dependence in data published by Yoshino & Yamauchi for edge-on galaxies.) There are also strong trends with other galaxy parameters – e.g. Hubble type: 77 per cent of S0–Sbc bars, but only 15 per cent of Sc–Sd bars, have B/P bulges – but these appear to be side effects of the correlations of these parameters with stellar mass. In particular, despite indications from models that a high gas content can suppress bar buckling, we find no evidence that the (atomic) gas mass ratio $M_{\mathrm{H}\, \small {I} + \mathrm{He}}/M_{\star }$ affects the presence of B/P bulges, once the stellar-mass dependence is controlled for. The semimajor axes of B/P bulges range from one-quarter to three-quarters of the full bar size, with a mean of R box / L bar = 0.42 ± 0.09 and R box / a ε = 0.53 ± 0.12 (where R box is the size of the B/P bulge and a ε and L bar are lower and upper limits on the size of the bar).