2017/07/02 by F. S. Liu, Dongfei Jiang, S. M. Faber +13 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Dust lane #Effective radius #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #RADIUS #Star formation #astro-ph.GA
paper · pdf · doi:10.3847/2041-8213/aa7cf5
10 pages, 4 figures, 1 table, accepted for publication in ApJL
arxiv created 2017/07/02 · openalex created_date 2017/07/14 · openalex publication_date 2017/07/14 · arxiv updated 2017/08/02 · openalex updated_date 2026/08/05
Abstract The rest-frame UV–optical (i.e., NUV − B ) color is sensitive to both low-level recent star formation (specific star formation rate—sSFR) and dust. In this Letter, we extend our previous work on the origins of NUV − B color gradients in star-forming galaxies (SFGs) at to those at . We use a sample of 1335 large (semimajor axis radius ) SFGs with extended UV emission out to in the mass range at in the CANDELS/GOODS-S and UDS fields. We show that these SFGs generally have negative NUV − B color gradients (redder centers), and their color gradients strongly increase with galaxy mass. We also show that the global rest-frame FUV − NUV color is approximately linear with , which is derived by modeling the observed integrated FUV to NIR spectral energy distributions of the galaxies. Applying this integrated calibration to our spatially resolved data, we find a negative dust gradient (more dust extinguished in the centers), which steadily becomes steeper with galaxy mass. We further find that the NUV − B color gradients become nearly zero after correcting for dust gradients regardless of galaxy mass. This indicates that the sSFR gradients are negligible and dust reddening is likely the principal cause of negative UV–optical color gradients in these SFGs. Our findings support that the buildup of the stellar mass in SFGs at Cosmic Noon is self-similar inside .