UV-IR color profiles of the outer regions of 2K nearby S${}^4$G galaxies

Abstract

We present our new, spatially-resolved, photometry in FUV and NUV from images obtained by GALEX, and IRAC1 (3.6 $\mu$m) photometry obtained by the Spitzer Space Telescope. We analyzed the surface brightness profiles ${\mu }_{\mathrm{FUV}}$, ${\mu }_{\mathrm{NUV}}$, ${\mu }_{[3.6]}$, as well as the radial evolution of the (FUV-NUV), (FUV - [3.6]), and (NUV - [3.6]) colors in the Spitzer Survey of Stellar Structures in Galaxies (S${}^4$G) galaxies (d$<$40 Mpc) sample. We defined the GALEX Blue Sequence (GBS) and GALEX Red Sequence (GBR) from the (FUV - NUV) versus (NUV - [3.6]) color-color diagram, populated by late-type star forming galaxies and quiescent early-type galaxies respectively. While most disk becomes radially bluer for GBS galaxies, and stay constant for GRS galaxies, a large fraction ($>$50%) of intermediary GALEX Green Valley (GGV) galaxies' outer disks are becoming redder. An outside-in quenching mechanism such as environmentally-related mechanisms such as starvation or ram-pressure-stripping could explain our results.

3 pages 1 figure, to be published in the Proceedings of IAU Symposium 321, "Formation and evolution of galaxy outskirts", Eds. A. Gil de Paz, J. C. Lee & J. H. Knapen, Cambridge University Press, Cambridge

References in corpus (6)

• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• The GALEX Ultraviolet Atlas of Nearby Galaxies
• Cold gas accretion in galaxies
• The Spitzer Survey of Stellar Structure in Galaxies (S^4G)
• Star formation sustained by gas accretion
• The GALEX/S4G UV-IR color-color diagram: Catching spiral galaxies away from the Blue Sequence

Cited by in corpus (1)

• WALLABY Pilot Survey: Hydra Cluster Galaxies UV and HI morphometrics