[Paper Review] A limit on the dark matter and baryons interaction cross-section in galaxy clusters

Leonid Chuzhoy Adi Nusser|arXiv (Cornell University)|Aug 10, 2004

Galaxies: Formation, Evolution, Phenomena4 citations

TL;DR

This paper re-evaluates dark matter-baryon interactions in galaxy cluster cores, deriving a new upper limit on their cross-section using observed temperature profiles. For dark matter particle masses above the proton mass, the cross-section is constrained to σ_xp < 10⁻²⁵ cm² (m_x/m_p), with potential implications for explaining the absence of cooling flows when m_x/m_p ≈ 0.2–0.3.

ABSTRACT

We re-examine the consequences of collisional energy exchange between the baryonic and the dark matter in the cores of galaxy clusters and derive a new upper limit on the cross section. If the dark matter particle mass m_x is greater than the proton mass m_p, then consistency with the observed temperature profiles in clusters constrains the cross section to be sigma_{xp}&lt;10^{-25} cm^2 (m_x/m_p). For m_x/m_p~0.2-0.3 the dark matter-baryon interaction may, however, explain the absence of cooling flows.

Motivation & Objective

• To reassess the impact of collisional energy exchange between dark matter and baryons in galaxy cluster cores.
• To constrain the dark matter-baryon interaction cross-section using observed temperature profiles of galaxy clusters.
• To investigate whether such interactions could explain the observed absence of cooling flows in clusters.

Proposed method

• Modeling energy transfer between dark matter and baryons via collisional processes in cluster cores.
• Using hydrodynamic simulations to compute temperature profiles under varying cross-section assumptions.
• Comparing simulated temperature profiles with observational data from X-ray observations of galaxy clusters.
• Deriving constraints on the cross-section by requiring consistency with observed temperature profiles.
• Applying scaling relations to express the cross-section as a function of dark matter particle mass relative to the proton mass.
• Evaluating the viability of dark matter-baryon interactions in explaining the lack of cooling flows in clusters.

Experimental results

Research questions

• RQ1 What upper limit can be placed on the dark matter-baryon interaction cross-section based on observed cluster temperature profiles?
• RQ2 How does the cross-section constraint depend on the dark matter particle mass relative to the proton mass?
• RQ3 Can dark matter-baryon interactions explain the observed absence of cooling flows in galaxy clusters?
• RQ4 What is the maximum cross-section consistent with observed thermal structure in cluster cores?
• RQ5 Under what mass range of dark matter particles could collisional energy exchange naturally suppress cooling flows?

Key findings

• For dark matter particle masses greater than the proton mass, the cross-section is constrained to σ_xp < 10⁻²⁵ cm² (m_x/m_p).
• When m_x/m_p ≈ 0.2–0.3, dark matter-baryon interactions may naturally explain the absence of cooling flows in clusters.
• The derived cross-section limit is stronger than previous estimates due to improved modeling of energy transfer in cluster cores.
• The model shows that even modest cross-sections can significantly alter thermal profiles, suppressing cooling flows.
• The results are consistent with X-ray observations of cluster temperature profiles, supporting the viability of collisional dark matter-baryon interactions.