James Webb Space Telescope Feed Post

Date: 2/13/2024

Arxiv: JWST reveals a high fraction of disk breaks at 1\leq z\leq 3 Published: 2/6/2024 8:41:10 PM Updated: 2/12/2024 3:09:46 PM

Paper abstract: We analyzed the deconvolved surface brightness profiles of 247 massive andangularly large disk galaxies at 1<= z<= 3 to study high-redshift diskbreaks, using F356W-band images from the Cosmic Evolution Early Release Sciencesurvey (CEERS). We found that 12.6% of these galaxies exhibit type I(exponential) profiles, 56.7% exhibit type II (down-bending) profiles, and34.8% exhibit type III (up-bending) profiles. Moreover, we showed that galaxiesthat are more massive, centrally concentrated, or redder, tend to show fewertype II and more type III breaks. These fractions and the detected dependencieson galaxy properties are in good agreement with those observed in the LocalUniverse. In particular, the ratio of the type II disk break radius to the barradius in barred galaxies typically peaks at a value of 2.25, perhaps due tobar-induced radial migration. However, the timescale for secular evolution maybe too lengthy to explain the observed breaks at such high redshifts. Instead,violent disk instabilities may be responsible, where spiral arms and clumpstorque fling out the material, leading to the formation of outer exponentialdisks. Our results provide further evidence for the assertion that the HubbleSequence was already in place during these early periods.