Hierarchical formation of bulgeless galaxies - II. Redistribution of angular momentum via galactic fountains: Bulgeless discs II

Brook, C. B.; Stinson, G.; Gibson, B. K.; Roškar, R.; Wadsley, J.; Quinn, T.

Abstract

Within a fully cosmological hydrodynamical simulation, we form a galaxy which rotates at 140 kms-1, and it is characterized by two loose spiral arms and a bar, indicative of a Hubble-type SBc/d galaxy. We show that our simulated galaxy has no classical bulge, with a pure disc profile atz= 1, well after the major merging activity has ended. A long-lived bar subsequently forms, resulting in the formation of a secularly formed 'pseudo-'bulge, with the final bulge-to-total light ratio of 0.21. We show that the majority of gas which loses angular momentum and falls to the central region of the galaxy during the merging epoch is blown back into the hot halo, with much of it returning later to form stars in the disc. We propose that this mechanism of redistribution of angular momentum via a galactic fountain, when coupled with the results from our previous study which showed why gas outflows are biased to have low angular momentum, can solve the angular momentum/bulgeless disc problem of the cold dark matter paradigm.

Citation

Brook, C. B., Stinson, G., Gibson, B. K., Roškar, R., Wadsley, J., & Quinn, T. (2012). Hierarchical formation of bulgeless galaxies - II. Redistribution of angular momentum via galactic fountains: Bulgeless discs II. Monthly notices of the Royal Astronomical Society, 419(1), 771-779. https://doi.org/10.1111/j.1365-2966.2011.19740.x

• Journal Article Type: Article
• Acceptance Date: Aug 31, 2011
• Online Publication Date: Oct 20, 2011
• Publication Date: Jan 1, 2012
• Deposit Date: May 15, 2018
• Journal: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 419
• Issue: 1
• Pages: 771-779
• DOI: https://doi.org/10.1111/j.1365-2966.2011.19740.x
• Public URL: https://hull-repository.worktribe.com/output/541319