Explosive Galaxy Evolution Via Minor Mergers At High Redshifts.pdf

They focus on how these low-mass galaxy mergers contribute to the rapid appearance of massive galaxies observed in the early universe.

Main Findings:

1. Smoluchowski Equation Solution: The authors derive an analytical solution for the kinetic Smoluchowski equation describing the evolution of the galaxy mass function (MF) under the influence of minor mergers.

2. Explosive Evolution: The solution reveals an explosive growth phase in galaxy mass, characterized by a rapid increase in the number of massive galaxies at high redshifts.

3. Role of Dark Matter: The model incorporates dark matter through its effect on the merging process and the overall expansion of the universe.

4. Power-Law Asymptote: They discuss the evolution of the power-law asymptote of the galaxy mass function at large redshifts, providing insights into the underlying physical mechanisms.

Methodology:

The authors use a differential form of the Smoluchowski kinetic equation, transforming it to a characteristics method for solution. They consider a source term representing galaxies with masses increasing from general expansion (not just background).

Key Implications:

Rapid Galaxy Formation: Minor mergers can explain the sudden appearance of massive galaxies at high redshifts.
Dark Matter Influence: The presence and contribution of dark matter are crucial for understanding both the merging process and the overall galaxy evolution.
* Comparative Analysis: By comparing their solutions with observational data, researchers can gain insights into the role of dark matter and interaction between galaxies in the early universe.