Constraining merger geometry of galaxy clusters with multi-wavelength observations and hydrodynamical simulations: The case of Abell 2146
Abstract
Merging galaxy clusters provide unique constraints on the nature of dark matter and the plasma physics of X-ray emitting intracluster medium (ICM). Offsets between the collisionless stars, dissipative gas, and lensing mass in merging systems like the Bullet Cluster provide constraints on the self-interaction cross-section of the dark matter. Properties of shock and cold fronts yield unique constrains on the microphysics of the ICM, such as the efficiency of electron-proton (e-p) equilibration, conductivity, and viscosity. However, given the complex structure of merging clusters, hydrodynamical simulations matching their geometry and dynamics are vital to meaningfully extract physical properties of dark matter and ICM plasma physics from observations. In this work, we present a novel method to constrain parameters of merging galaxy clusters, including the masses, impact parameter and relative velocities of two merging galaxy clusters, by using X-ray emissivity and temperature and lensing maps as well as automated detection of shock and cold fronts and Mach number across them. We test this method by analyzing mock X-ray and lensing observations of a suite of idealized galaxy cluster merger simulations performed using the GPU-accelerated adaptive mesh refinement code GAMER-2. We will also discuss the application of this method to the Chandra-VLP observations of the merging Bullet-like cluster Abell 2146.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1740006C