Smoothed particle inference : A kilo-parametric method for X-ray galaxy cluster modeling

• We propose an ambitious new method that models the intracluster medium in clusters of galaxies as a set of X-ray-emitting smoothed particles of plasma. Each smoothed particle is described by a handful of parameters including temperature, location, size, and elemental abundances. Hundreds to thousands of these particles are used to construct a model cluster of galaxies, with the appropriate complexity estimated from the data quality. This model is then compared iteratively with X-ray data in the form of adaptively binned photon lists via a two-sample likelihood statistic and iterated via Markov chain Monte Carlo. The complex cluster model is propagated through the X-ray instrument response using direct sampling Monte Carlo methods. With this approach, the method can reproduce many of the features observed in the X- ray emission in a less assumption-dependent way than traditional analyses, and it allows for a more detailed characterization of the density, temperature, and metal abundance structure of clusters. Multi-instrument X- ray analyses and simultaneous X- ray, Sunyaev-Zeldovich ( SZ), and lensing analyses are a straightforward extension of this methodology. Significant challenges still exist in understanding the degeneracy in these models and the statistical noise induced by the complexity of the models.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

methods

data analysis

X-rays

galaxies

clusters

zeldovich effect data

perseus cluster

chandra observations

joint analysis

xmm-newton

core

spectroscopy

merger

gas

Astronomy and astrophysics

Astronomi och astrofysik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)