BibTeX

@article{2505.14378v2,
Author        = {Alexeï Molin and Simon Dupourqué and Nicolas Clerc and Étienne Pointecouteau and François Pajot and Edoardo Cucchetti},
Title         = {Toward mapping turbulence in the intracluster medium IV. Using
  NewAthena/X-IFU and simulation based inference to constrain turbulence},
Eprint        = {2505.14378v2},
ArchivePrefix = {arXiv},
PrimaryClass  = {astro-ph.CO},
Abstract      = {Context. The NewAthena mission planned for launch in the late 2030s will
carry X-IFU, an integral field unit spectrometer that will obtain unique
insight into the X-ray hot universe through its combination of spectral and
spatial capabilities. Its high spectral resolution will allow a mapping of
turbulent velocities of the hot gas in galaxy clusters, providing an unrivaled
way to study the complex dynamics within galaxy clusters. Aims. This is the
fourth in a series of papers aimed at forecasting the ability to investigate
turbulence in the intracluster medium through the observation of the centroid
shift caused by turbulent motions of the gas. In this paper we improve on
previous methods by investigating the ability of simulation-based inference
(SBI) to constrain the underlying nature of velocity fluctuations through the
use of standard observational diagnostics, such as the structure function.
Methods. We rely on a complex architecture of neural networks in order to model
the likelihood and posterior distributions relevant to our case. We investigate
its capability to retrieve the turbulence parameters on mock observations, and
explore its capability to use alternative summary statistics. Results. Our
trained models are able to infer the parameters of the intracluster gas
velocity power-spectrum in independently simulated X-IFU observations of a
galaxy cluster. We evaluated the precision of the recovery for different
models. We show the necessity to use methods such as SBI to avoid an
under-estimation of the sources of variance by comparing the results to our
previous paper. We confirm that sample variance severely impacts the precision
of recovered turbulent features. Our results demonstrate the need for advanced
modeling methods to tackle the complexity of the physical information nested
within future observations expected from X-IFU/NewAthena.},
Year          = {2025},
Month         = {May},
Url           = {http://arxiv.org/abs/2505.14378v2},
File          = {2505.14378v2.pdf}
}