CLEAR: The Evolution of Spatially Resolved Star Formation in Galaxies between 0.5 z 1.7 Using H Emission Line Maps Academic Article uri icon


  • Abstract Using spatially resolved H emission line maps of star-forming galaxies, we study the spatial distribution of star formation over a wide range in redshift (0.5 z 1.7). Our z 0.5 measurements come from deep Hubble Space Telescope (HST) Wide Field Camera 3 G102 grism spectroscopy obtained as part of the CANDELS Ly Emission at Reionization Experiment. For star-forming galaxies with log(M */M ) 8.96, the mean H effective radius is 1.2 0.1 times larger than that of the stellar continuum, implying inside-out growth via star formation. This measurement agrees within 1 with those measured at z 1 and z 1.7 from the 3D-HST and KMOS3D surveys, respectively, implying no redshift evolution. However, we observe redshift evolution in the stellar mass surface density within 1 kpc (1kpc). Star-forming galaxies at z 0.5 with a stellar mass of log(M */M ) = 9.5 have a ratio of 1kpc in H relative to their stellar continuum that is lower by (19 2)% compared to z 1 galaxies. 1kpc,H /1kpc,Cont decreases toward higher stellar masses. The majority of the redshift evolution in 1kpc,H /1kpc,Cont versus stellar mass stems from the fact that log(1kpc,H ) declines twice as much as log(1kpc,Cont) from z 1 to 0.5 (at a fixed stellar mass of log(M */M ) = 9.5). By comparing our results to the TNG50 cosmological magneto-hydrodynamical simulation, we rule out dust as the driver of this evolution. Our results are consistent with inside-out quenching following in the wake of inside-out growth, the former of which drives the significant drop in 1kpc,H from z 1 to z 0.5.

published proceedings

  • The Astrophysical Journal

author list (cited authors)

  • Matharu, J., Papovich, C., Simons, R. C., Momcheva, I., Brammer, G., Ji, Z., ... Weiner, B.

complete list of authors

  • Matharu, Jasleen||Papovich, Casey||Simons, Raymond C||Momcheva, Ivelina||Brammer, Gabriel||Ji, Zhiyuan||Backhaus, Bren E||Cleri, Nikko J||Estrada-Carpenter, Vicente||Finkelstein, Steven L||Finlator, Kristian||Giavalisco, Mauro||Jung, Intae||Muzzin, Adam||Nelson, Erica J||Pillepich, Annalisa||Trump, Jonathan R||Weiner, Benjamin

publication date

  • September 2022