# Exploring Self-Interacting Dark Matter Halos with Diverse Baryonic Distributions: A Parametric Approach

**Authors:** Daneng Yang  
**arXiv:** [2405.03787](https://arxiv.org/abs/2405.03787)  
**Date:** 2024-05-06  
**Summary page:** https://www.summarizepaper.com/en/paper/2405.03787v1/

## Key points

- Daneng Yang from the Department of Physics and Astronomy at the University of California, Riverside, explores galaxies and dark matter halos within self-interacting dark matter (SIDM) models.
- Gravitational effects of galaxies on dark matter halos are crucial in shaping their structure and dynamics.
- Yang extends a parametric model to include baryonic components for a more comprehensive representation of SIDM halo density profiles over time.
- The study introduces the concept of a fictitious progenitor NFW halo influenced by baryonic potentials to characterize temporal evolution.
- A form factor is incorporated to rescale evolution time in the absence of baryons, introducing a universal phase.
- Halo density profile is parametrized by Yang to consider influences from baryonic components in the radial dimension.
- Calibration using N-body simulations with baryon potentials validates and refines this parametric approach for various stellar-to-halo mass ratios and size-mass relationships.
- The methodology's numerical efficiency allows extensive exploration of SIDM effects across diverse halos.
- Illustrative case study spanning five orders of magnitude demonstrates how evolution history and specific SIDM models can be disentangled from current states for post-processing analyses.

## Summary

In this study, Daneng Yang from the Department of Physics and Astronomy at the University of California, Riverside, delves into the intricate interplay between galaxies and dark matter halos within the framework of self-interacting dark matter (SIDM) models. The gravitational effects exerted by galaxies on dark matter halos play a crucial role in shaping their structure and dynamics. As we consider a diverse range of galactic structures and varying dark matter halo profiles, the complexity of these interactions increases. Building upon a parametric model initially developed for dark matter-only halos, Yang extends this model to incorporate baryonic components. This provides a more comprehensive representation of SIDM halo density profiles over time. By highlighting the significance of a gravothermal phase in characterizing the state of an SIDM halo, the study introduces the concept of a fictitious progenitor – an NFW halo influenced by baryonic potentials – that has evolved to its current state. This temporal evolution is further refined through the incorporation of a form factor that rescales evolution time in the absence of baryons, allowing for the introduction of a universal phase. Moreover, in considering the radial dimension, Yang parametrizes the halo density profile to account for the influences exerted by baryonic components. Through calibration using N-body simulations with baryon potentials, various stellar-to-halo mass ratios and size-mass relationships are fitted to validate and refine this parametric approach. The numerical efficiency afforded by this methodology enables an extensive exploration of SIDM effects across a diverse array of halos. Illustrating their findings through a case study involving an illustrative sample spanning five orders of magnitude in mass range, Yang demonstrates how evolution history and specific SIDM models can be disentangled from current states of galaxies and halos. This separation allows for dedicated post-processing analyses aimed at identifying consistent SIDM models that accurately capture the complex interactions between galaxies and dark matter halos. Through their meticulous approach and detailed analysis, Yang provides valuable insights into understanding self-interacting dark matter halos with diverse baryonic distributions using a sophisticated parametric framework.