Galaxy Zoo: CANDELS Barred Disks and Bar Fractions
Abstract
The formation of bars in disk galaxies is a tracer of the dynamical maturity of the population. Previous studies have found that the incidence of bars in disks decreases from the local Universe to z ~ 1, and by z > 1 simulations predict that bar features in dynamically mature disks should be extremely rare. Here we report the discovery of strong barred structures in massive disk galaxies at z ~ 1.5 in deep rest-frame optical images from CANDELS. From within a sample of 876 disk galaxies identified by visual classification in Galaxy Zoo, we identify 123 barred galaxies. Selecting a sub-sample within the same region of the evolving galaxy luminosity function (brighter than L*), we find that the bar fraction across the redshift range 0.5< z < 2 (f_bar = 10.7 +6.3 -3.5% after correcting for incompleteness) does not significantly evolve. We discuss the implications of this discovery in the context of existing simulations and our current understanding of the way disk galaxies have evolved over the last 11 billion years.
Keywords
Cite
@article{arxiv.1409.1214,
title = {Galaxy Zoo: CANDELS Barred Disks and Bar Fractions},
author = {B. D. Simmons and Thomas Melvin and Chris Lintott and Karen L. Masters and Kyle W. Willett and William C. Keel and R. J. Smethurst and Edmond Cheung and Robert C. Nichol and Kevin Schawinski and Michael Rutkowski and Jeyhan S. Kartaltepe and Eric F. Bell and Kevin R. V. Casteels and Christopher J. Conselice and Omar Almaini and Henry C. Ferguson and Lucy Fortson and William Hartley and Dale Kocevski and Anton M. Koekemoer and Daniel H. McIntosh and Alice Mortlock and Jeffrey A. Newman and Jamie Ownsworth and Steven Bamford and Tomas Dahlen and Sandra M. Faber and Steven L. Finkelstein and Adriano Fontana and Audrey Galametz and N. A. Grogin and Ruth Grutzbauch and Yicheng Guo and Boris Haussler and Kian J. Jek and Sugata Kaviraj and Ray A. Lucas and Michael Peth and Mara Salvato and Tommy Wiklind and Stijn Wuyts},
journal= {arXiv preprint arXiv:1409.1214},
year = {2016}
}
Comments
11 pages, 6 figures; accepted for publication in MNRAS