Evolution of bar formation in galaxies over the last 6 giga-years

Abstract

This work examines the evolution of bar formation in disk galaxies over the last 6 giga-years by analyzing the barred galaxy fraction as a function of key structural parameters. A representative sample of local and distant field galaxies was studied using bar detection techniques based on elliptical isophotes and Fourier decomposition. The analysis focuses on the dependence of bar formation on stellar mass, color index, and bulge-to-total ratio (B/T). In the local universe, the bar fraction increases with stellar mass and is higher in red, more evolved galaxies, suggesting that disk stability plays a fundamental role in bar formation. In contrast, distant galaxies exhibit a significantly lower bar fraction, indicating that dynamically unstable disks in earlier cosmic epochs limited both the formation and persistence of bars. Bars are more frequent in galaxies with disk-dominated structures (low B/T) at all redshifts; however, even these systems show a reduced bar fraction at higher redshift. Overall, the results highlight the importance of disk stabilization in driving the morphological evolution of galaxies across cosmic time.