The SAMI Galaxy Survey:observing the environmental quenching of star formation in GAMA groups

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Schaefer, A. L., Croom, S. M., Scott, N., Brough, S., Allen, J. T., Bekki, K., Bland-Hawthorn, J., Bloom, J. V., Bryant, J. J., Cortese, L., Davies, L. J. M., Federrath, C., Fogarty, L. M. R., Green, A. W., Groves, B., Hopkins, A. M., Konstantopoulos, I. S., López-Sánchez, A. R., Lawrence, J. S., McElroy, R. E., Medling, A. M., Owers, M. S., Pracy, M. B., Richards, S. N., Robotham, A. S. G., van de Sande, J., Tonini, C., Yi, S. K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Galaxies: evolution; Galaxies: groups: general; Galaxies: interactions; Galaxies: star formation; Galaxies: structure; sami
• Online Access: https://researchers.mq.edu.au/en/publications/f708414a-1971-4dbc-ab41-1f19f8ab6efc; https://doi.org/10.1093/mnras/sty3258; http://www.scopus.com/inward/record.url?scp=85063587208&partnerID=8YFLogxK; http://purl.org/au-research/grants/arc/FT140100255; http://purl.org/au-research/grants/arc/CE170100013

We explore the radial distribution of star formation in galaxies in the SAMI Galaxy Survey as a function of their Local Group environment. Using a sample of galaxies in groups (with halo masses less than ≃ 10 14 M ⊙ ) from the Galaxy And Mass Assembly Survey, we find signatures of environmental quenching in high-mass groups (M G > 10 12.5 M ⊙ ). The mean integrated specific star formation rate (sSFR) of star-forming galaxies in high-mass groups is lower than for galaxies in low-mass groups or those that are ungrouped, with Δlog(sSFR/yr -1 ) = 0.45 ± 0.07. This difference is seen at all galaxy stellar masses. In high-mass groups, starforming galaxies more massive than M ∗ ∼ 10 10 M ⊙ have centrally concentrated star formation. These galaxies also lie below the star formation main sequence, which suggests they may be undergoing outside-in quenching. Lower mass galaxies in high-mass groups do not show evidence of concentrated star formation. In groups less massive than M G = 10 12.5 M ⊙ , we do not observe these trends. In this regime, we find a modest correlation between centrally concentrated star formation and an enhancement in the total star formation rate, consistent with triggered star formation in these galaxies.