sunidhi,
Abstract
We have developed a detailed model to understand how galaxies form in the framework of hierarchical theories of structure formation. Our model accounts for key processes like the formation and merging of dark matter halos, the heating and cooling of gas inside these halos, the regulation of star formation driven by energy from evolving stars and supernovae, galaxy mergers, and the changes in star populations over time. This approach is very flexible and can be used with any hierarchical clustering theory. We base our star formation and galaxy merging models on insights from numerical simulations. With this, we can predict things like the number of galaxies, their brightness, color, and how fast they rotate. The study focuses on the standard cold dark matter (CDM) model, and we also examine how different assumptions—like star formation rates or galaxy mergers—affect the results. We compare our predictions to a wide range of observational data, including galaxy luminosity functions in the B and K bands, galaxy colors, the Tully-Fisher relation, faint galaxy counts, and redshift distributions at B ~ 22. By doing this, we can narrow down the most important physical processes and get a better idea of how galaxies form. Our model performs quite well when we use a reasonable set of parameters. It produces a more accurate galaxy luminosity function than previous models and explains the observed counts of faint galaxies in both the B and K bands, as well as their redshift distributions. However, the model has its shortcomings. It does not quite match the color of many observed elliptical galaxies.
Keywords: Galaxy formation, dark matter halos, star formation, galaxy mergers, cold dark matter (CDM)
[This article belongs to International Journal of Universe ]
sunidhi. Modeling Galaxy Formation in a Hierarchical Universe: A Fiducial Approach and Comparison with Observational Data. International Journal of Universe. 2025; 01(01):30-36.
sunidhi. Modeling Galaxy Formation in a Hierarchical Universe: A Fiducial Approach and Comparison with Observational Data. International Journal of Universe. 2025; 01(01):30-36. Available from: https://journals.stmjournals.com/iju/article=2025/view=233668
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| Volume | 01 |
| Issue | 01 |
| Received | 07/08/2025 |
| Accepted | 12/09/2025 |
| Published | 20/10/2025 |
| Publication Time | 74 Days |
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