Astronomy Tea Talk

Galaxy morphology provides a crucial constraint on their formation process however most studies focus on the half-light radii at optical wavelengths. Optical light can be biased away from the underlying stellar mass distribution of galaxies by color gradients, which trace variation in the mass-to-light ratio (M/L). In this talk, I will present results measuring color gradients and half-mass radii for roughly 3000 galaxies between 1 < z < 2 using HST data from the CANDELS survey. We use a new method, imcascade which flexibly represents galaxy profiles using a series of Gaussians to accurately measure the profiles of galaxies. I will discuss the evolution of color gradients with redshift and how they affect the ratio between half-mass and half-light radii. I will highlight that most of the evolution of the half-light radii of galaxies between redshifts one and two is due to changing color gradients rather than changes to the intrinsic stellar mass distribution of galaxies. Finally I will discuss some very exciting results using early JWST data that measure rest frame NIR sizes of galaxies and understanding variations in stellar populations using NIR color gradients.