Evolution of the early-type fraction in massive galaxies at z < 2: how did early-type morphology form?

Abstract Using JWST/NIRCam data over a 0.28 deg2 area from COSMOS-Web survey, together with HST/ACS data, we investigate early-type fraction of massive galaxies with Mstar &amp;gt; 1010.5M⊙ at 0.2 &amp;lt; z &amp;lt; 2.0, and explore the formation of their early-type morphology. We measure concentration index C (=R80/R20) and asymmetry index A, and select early-type galaxies with C &amp;gt; Cn = 2.5 and Acor &amp;lt; 0.2. Here Cn = 2.5 is the concentration expected for a Sérsic profile with n =