Comparison of Star Formation Rates (SFRs) in Spiral and Elliptical Galaxies

Abstract: 

This paper examines the impact of star formation rate (SFR) and U-R filter values on galaxy classification. This research is significant because star formation plays a central role in galaxy development, and accurately classifying galaxies helps to further cosmological studies. Using a dataset from ViZieR based on Sloan Digital Sky Survey (SDSS) data, the study analyzes photometric ugriz magnitude filters, redshift, flux values, and WISE passbands for 1,000 galaxies. A multiple regression machine learning model was built to predict galaxy types — elliptical or spiral — based on SFR and redshift, incorporating the known classification standard that galaxies with U-R values greater than 2.22 are classified as elliptical. In contrast, those with values below 2.22 are classified as spiral. The results show that spiral galaxies exhibit higher ongoing SFR compared to elliptical galaxies, despite elliptical galaxies having higher initial star formation in the early stages.

Furthermore, a direct linear relationship was observed between stellar mass and SFR for spiral galaxies, whereas elliptical galaxies exhibited negligible changes in SFR with increasing mass. Madau plots also demonstrated an increasing trend of log SFR with redshift within the

sample range. The study concludes that while elliptical galaxies formed stars more rapidly initially, spiral galaxies maintain higher SFR over time, highlighting differences in gas availability and evolutionary processes. Future research will expand to include other galaxy types and higher redshift samples, thereby deepening the understanding of galaxy formation and classification frameworks.