The SAMI Galaxy Survey: Spatially resolving the environmental quenching of star formation in GAMA galaxies

• Main Authors: Schaefer, A. L., Croom, S. M., Allen, J. T., Brough, S., Medling, A. M., Ho, I. -T., Scott, N., Richards, S. N., Pracy, M. B., Gunawardhana, M. L. P., Norberg, P., Alpaslan, M., Bauer, A. E., Bekki, K., Bland-Hawthorn, J., Bloom, J. V., Bryant, J. J., Couch, W. J., Driver, S. P., Fogarty, L. M. R., Foster, C., Goldstein, G., Green, A. W., Hopkins, A. M., Konstantopoulos, I. S., Lawrence, J. S., López-Sánchez, A. R., Lorente, N. P. F., Owers, M. S., Sharp, R., Sweet, S. M., Taylor, E. N., van de Sande, J., Walcher, C. J., Wong, O. I.
• Format: Text
• Language: unknown
• Published: arXiv 2016
• Subjects: Astrophysics of Galaxies astro-ph.GA; FOS Physical sciences; sami
• Online Access: https://dx.doi.org/10.48550/arxiv.1609.02635; https://arxiv.org/abs/1609.02635

We use data from the Sydney-AAO Multi-Object Integral Field Spectrograph (SAMI) Galaxy Survey and the Galaxy And Mass Assembly (GAMA) survey to investigate the spatially-resolved signatures of the environmental quenching of star formation in galaxies. Using dust-corrected measurements of the distribution of H$α$ emission we measure the radial profiles of star formation in a sample of 201 star-forming galaxies covering three orders of magnitude in stellar mass (M$_{*}$; $10^{8.1}$-$10^{10.95}\, $M$_{\odot}$) and in $5^{th}$ nearest neighbour local environment density ($Σ_{5}$; $10^{-1.3}$-$10^{2.1}\,$Mpc$^{-2}$). We show that star formation rate gradients in galaxies are steeper in dense ($\log_{10}(Σ_{5}/$Mpc$^{2})>0.5$) environments by $0.58\pm 0.29\, dex\, $r$_{e}^{-1}$ in galaxies with stellar masses in the range $10^{10}1.0$). These lines of evidence strongly suggest that with increasing local environment density the star formation in galaxies is suppressed, and that this starts in their outskirts such that quenching occurs in an outside-in fashion in dense environments and is not instantaneous. : 24 pages, 16 figures, accepted for publication in MNRAS