Baryons' Role in Shaping Dark Matter Halo Structures

Recent research conducted by Daniele Sorini and colleagues has explored the influence of baryons on the internal structure of dark matter haloes across a wide range of cosmic scales, from dwarf galaxies to superclusters, within the redshift range of 0 to 7. The study utilizes advanced cosmological hydrodynamic simulations, specifically the IllustrisTNG suite and the MillenniumTNG simulation, to analyze the concentration-mass relationship of dark matter haloes.

The findings indicate that the presence of baryons significantly alters the concentration-mass relationship, particularly at higher redshifts. This alteration is attributed to adiabatic contraction driven by gas accretion, which enhances star formation in the inner regions of haloes. Conversely, at lower redshifts, the effects of feedback mechanisms lead to a decrease in halo concentration for masses below approximately 10^11.5 solar masses.

The research also introduces a broken power-law model that effectively describes the redshift evolution of the concentration-mass relationship and the impact of baryons on the total mass of haloes. This model provides empirical parameters that can be applied to simulations mimicking baryonic effects in dark-matter-only frameworks over a broad mass range.

These insights are crucial for understanding the formation and evolution of cosmic structures, as they highlight the significant role baryons play in shaping the characteristics of dark matter haloes. The study is expected to influence future research in cosmology and astrophysics, particularly in the context of galaxy formation and the dynamics of dark matter.

The research paper is titled "The impact of baryons on the internal structure of dark matter haloes from dwarf galaxies to superclusters in the redshift range 0<z<7" and can be cited as arXiv:2409.01758.