Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/233040

Title

A diversity of progenitors and histories for isolated spiral galaxies

Author(s)

Martig, Marie;  Bournaud, Frederic;  Croton, Darren J.;  Dekel, Avishai;  Teyssier, Romain

Abstract

We analyze a suite of 33 cosmological simulations of the evolution of Milky-Way-mass galaxies in low-density environments. Our sample spans a broad range of Hubble types at z = 0, from nearly bulgeless disks to bulge-dominated galaxies. Despite the fact that a large fraction of the bulge is typically in place by z ~ 1, we find no significant correlation between the morphology at z = 1 and at z = 0. The z = 1 progenitors of disk galaxies span a range of morphologies, including smooth disks, unstable disks, interacting galaxies, and bulge dominated systems. By z ~ 0.5, spiral arms and bars are largely in place and the progenitor morphology is correlated with the final morphology. We next focus on late-type galaxies with a bulge-to-total ratio (B/T) <0.3 at z = 0. These show a correlation between B/T at z = 0 and the mass ratio of the largest merger at z < 2, as well as with the gas accretion rate at z > 1. We find that the galaxies with the lowest B/T tend to have a quiet baryon input history, with no major mergers at z < 2, and with a low and constant gas accretion rate that keeps a stable angular-momentum direction. More violent merger or gas accretion histories lead to galaxies with more prominent bulges. Most disk galaxies have a bulge S& 0233;rsic index n ≤ 2. The galaxies with the highest bulge Sérsic index tend to have histories of intense gas accretion and disk instability rather than active mergers.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Astrophysical Journal, Vol. 756, no. 1 (Sep 2012), article no. 26

Publication year

2012

FOR Code(s)

0201 Astronomical and Space Sciences;  0305 Organic Chemistry;  0306 Physical Chemistry (Incl. Structural)

Keyword(s)

Galaxy bulges;  Galaxy evolution;  Galaxy formation;  Galaxy interactions;  High-redshift;  Spiral galaxies

Publisher

Institute of Physics Publishing

ISSN

0004-637X

Publisher URL

http://dx.doi.org/10.1088/0004-637x/756/1/26

Copyright

Copyright © 2012 The American Astronomical Society. All rights reserved. The American Astronomical Society does not allow Swinburne Research Bank to archive either the accepted manuscript or the published version of the article. However you can find an earlier version of the full text here: http://arxiv.org/abs/1201.1079

Additional information

The authors acknowledge support from a QEII Fellowship awarded by the Australian government, the EC through grant ERC-StG-257720, the CosmoComp ITN, as ISF grant 6/08, by GIF grant G-1052-104.7/2009, and by a DIP grant.

Peer reviewed