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, Scott M., Scott, Nicholas, Brough, Sarah, Allen, James T., Bekki, Kenji, Bland-Hawthorn, J., Bloom, J. V., Bryant, J. J., Cortese, L., Federrath, Christoph, Groves, Brent Allan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing Ltd
• Subjects: galaxies: evolution; galaxies: interactions; galaxies: star formation; galaxies: structure; galaxies: groups: general; sami
• Online Access: http://hdl.handle.net/1885/232496; https://doi.org/10.1093/mnras/sty3258; https://openresearch-repository.anu.edu.au/bitstream/1885/232496/3/01_Schaefer_The_SAMI_Galaxy_Survey%253A_2019.pdf.jpg

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 similar or equal to 10(14) M-circle dot) from the Galaxy And Mass Assembly Survey, we find signatures of environmental quenching in high-mass groups (M-G > 10(12.5) M-circle dot). 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 Delta log(sSFR/yr(-1)) = 0.45 +/- 0.07. This difference is seen at all galaxy stellar masses. In high-mass groups, star-forming galaxies more massive than M-* similar to 10(10) M-circle dot 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-circle dot, 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. The SAMI Galaxy Survey is supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013, the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020, and other participating institutions. M.S.O. acknowledges the funding support from the Australian Research Council (ARC) through a Future Fellowship (FT140100255). J.T.A. acknowledges the award of a Science and Industry Endowment Fund (SIEF) John Stocker Fellowship. J.v.d.S. is funded under Bland-Hawthorn’s ARC Laureate Fellowship (FL140100278). S.B. acknowledges the funding support from the Australian Research Council ...