Davies, LJM and Robotham, ASG and Driver, SP and Alpaslan, M and Baldry, IK and Bland-Hawthorn, J and Brough, S and Brown, MJI and Cluver, ME and Drinkwater, MJ and Foster, C and Grootes, MW and Konstantopoulos, IS and Lara-Lopez, MA and Lopez-Sanchez, AR and Loveday, J and Meyer, MJ and Moffett, AJ and Norberg, P and Owers, MS et al and Popescu, CC and Propris, RD and Sharp, R and Tuffs, RJ and Wang, L and Wilkins, SM and Bourne, LDN and Smith, MWL (2015) Galaxy And Mass Assembly (GAMA): the effect of close interactions on star formation in galaxies. Monthly Notices of the Royal Astronomical Society, 452 (1). pp. 616-636. ISSN 0035-8711
This is the latest version of this item.
1507.04447v1.pdf - Accepted Version
The modification of star formation (SF) in galaxy interactions is a complex process, with SF observed to be both enhanced in major mergers and suppressed in minor pair interactions. Such changes likely to arise on short timescales and be directly related to the galaxy-galaxy interaction time. Here we investigate the link between dynamical phase and direct measures of SF on different timescales for pair galaxies, targeting numerous star-formation rate (SFR) indicators and comparing to pair separation, individual galaxy mass and pair mass ratio. We split our sample into the higher (primary) and lower (secondary) mass galaxies in each pair and find that SF is indeed enhanced in all primary galaxies but suppressed in secondaries of minor mergers. We find that changes in SF of primaries is consistent in both major and minor mergers, suggesting that SF in the more massive galaxy is agnostic to pair mass ratio. We also find that SF is enhanced/suppressed more strongly for short-time duration SFR indicators (e.g. H-alpha), highlighting recent changes to SF in these galaxies, which are likely to be induced by the interaction. We propose a scenario where the lower mass galaxy has its SF suppressed by gas heating or stripping, while the higher mass galaxy has its SF enhanced, potentially by tidal gas turbulence and shocks. This is consistent with the seemingly contradictory observations for both SF suppression and enhancement in close pairs.
|Additional Information:||This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record MNRAS (September 01, 2015) 452 (1): 616-636 is available online at: http://dx.doi.org/10.1093/mnras/stv1241|
|Uncontrolled Keywords:||0201 Astronomical And Space Sciences|
|Subjects:||Q Science > QB Astronomy|
|Divisions:||Astrophysics Research Institute|
|Publisher:||Oxford University Press|
|Date Deposited:||26 Oct 2015 14:02|
|Last Modified:||26 Oct 2015 14:02|
|DOI or Identification number:||10.1093/mnras/stv1241|
Available Versions of this Item
Galaxy And Mass Assembly (GAMA): the effect of close interactions on star formation in galaxies. (deposited 27 Jul 2015 15:02)
- Galaxy And Mass Assembly (GAMA): the effect of close interactions on star formation in galaxies. (deposited 26 Oct 2015 14:02) [Currently Displayed]
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