JWST morphological measurements at 4.4um & 1.5um

However, at z>~1 these studies have been limited by a lack of deep, high-resolution rest-frame infrared imaging that accurately traces stellar mass distributions. Here, we leverage the new capabilities of the James Webb Space Telescope (JWST) to measure the 4.4{mu}m sizes of ~1000 galaxies with logM_*_/M_{sun}_>=9 and 1.0<=z<=2.5 from public CEERS imaging in the Extended Groth Strip deep field.

We compare the sizes of galaxies measured from NIRCam imaging at 4.4{mu}m ({lambda}_rest_~1.6{mu}m) with sizes measured at 1.5{mu}m ({lambda}_rest_~5500{AA}). We find that, on average, galaxy half-light radii are ~9% smaller at 4.4{mu}m than 1.5{mu}m in this sample. This size difference is markedly stronger at higher stellar masses and redder rest-frame V-J colors: galaxies with M_*_~10^11^M_{sun}_ have 4.4{mu}m sizes that are ~30% smaller than their 1.5{mu}m sizes.