A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Galaxy And Mass Assembly (GAMA): the effect of close interactions on star formation in galaxies
Tekijät: Davies LJM, Robotham ASG, Driver SP, Alpaslan M, Baldry IK, Bland-Hawthorn J, Brough S, Brown MJI, Cluver ME, Drinkwater MJ, Foster C, Grootes MW, Konstantopoulos IS, Lara-Lopez MA, Lopez-Sanchez AR, Loveday J, Meyer MJ, Moffett AJ, Norberg P, Owers MS, Popescu CC, De Propris R, Sharp R, Tuffs RJ, Wang L, Wilkins SM, Dunne L, Bourne N, Smith MWL
Kustantaja: OXFORD UNIV PRESS
Julkaisuvuosi: 2015
Journal: Monthly Notices of the Royal Astronomical Society
Tietokannassa oleva lehden nimi: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Lehden akronyymi: MON NOT R ASTRON SOC
Vuosikerta: 452
Numero: 1
Aloitussivu: 616
Lopetussivu: 636
Sivujen määrä: 21
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stv1241
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 time-scales 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 time-scales 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 are 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-duration SFR indicators (e.g. Ha), 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.