Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 2482074

SZ–X-Ray Surface Brightness Fluctuations in the SPT-XMM Clusters

Romero, Charles E. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000157250359)·Gaspari, Massimo [Univ. of Modena & Reggio Emilia (Italy)] (ORCID:0000000327549258)·Schellenberger, Gerrit [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000249620740)·Benson, Bradford A. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics (KICP)] (ORCID:0000000251086823)·Bleem, Lindsey E. [Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics (KICP); Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000176655079)·Bulbul, Esra [Max Planck Inst. fuer Extraterrestrische Physik, Garching (Germany)] (ORCID:0000000276195399)·Forman, William [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000294781682)·Kraft, Ralph [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000207650511)·Nulsen, Paul [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Univ. of Western Australia, Crawley, WA (Australia)] (ORCID:0000000302974493)·Reichardt, Christian L. [Univ. of Melbourne, Parkville, VIC (Australia)] (ORCID:0000000322269169)·Sarkar, Arnab [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Kavli Institute for Astrophysics and Space Research] (ORCID:0000000252221337)·Somboonpanyakul, Taweewat [Chulalongkorn Univ. (Thailand)] (ORCID:0000000335213631)·Su, Yuanyuan [Univ. of Kentucky, Lexington, KY (United States)] (ORCID:0000000238861258)
View original source ↗Read source document ↗Export metadata ↓

Abstract

The hot plasma in galaxy clusters, the intracluster medium, is expected to be shaped by subsonic turbulent motions, which are key for heating, cooling, and transport mechanisms. The turbulent motions contribute to the nonthermal pressure, which, if not accounted for, consequently imparts a hydrostatic mass bias. Accessing information about turbulent motions is thus of major astrophysical and cosmological interest. Characteristics of turbulent motions can be indirectly accessed through surface brightness fluctuations. This study expands on our pilot investigations of surface brightness fluctuations in the Sunyaev–Zel’dovich and in X-ray data by examining, for the first time, a large sample of 60 clusters using both SPT-SZ and XMM-Newton data and spans the redshift range 0.2 < z < 1.5, thus constraining the respective pressure and density fluctuations within 0.6 R $_{500}$. We deem density fluctuations to be of sufficient quality for 32 clusters, finding mild correlations between the peak of the amplitude spectra of density fluctuations and various dynamical parameters. We infer turbulent velocities from density fluctuations with an average Mach number $\mathcal{M}$ 3D = 0.52 ± 0.14, in agreement with numerical simulations. For clusters with inferred turbulent Mach numbers from fluctuations in both pressure, $\mathcal{M}$ P , and density, $\mathcal{M}$ ρ , we find broad agreement between $\mathcal{M}$ P and $\mathcal{M}$ ρ . Our results suggest either a bimodal or a skewed unimodal Mach number distribution, with the majority of clusters being turbulence-dominated (subsonic) while the remainder are shock-dominated (supersonic).

Explore related subjects

79 ASTRONOMY AND ASTROPHYSICSgalaxy clustersintracluster medium

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Romero, Charles E. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000157250359), Gaspari, Massimo [Univ. of Modena & Reggio Emilia (Italy)] (ORCID:0000000327549258), Schellenberger, Gerrit [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000249620740), Benson, Bradford A. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics (KICP)] (ORCID:0000000251086823), Bleem, Lindsey E. [Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics (KICP); Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000176655079), Bulbul, Esra [Max Planck Inst. fuer Extraterrestrische Physik, Garching (Germany)] (ORCID:0000000276195399), Forman, William [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000294781682), Kraft, Ralph [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)] (ORCID:0000000207650511), Nulsen, Paul [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Univ. of Western Australia, Crawley, WA (Australia)] (ORCID:0000000302974493), Reichardt, Christian L. [Univ. of Melbourne, Parkville, VIC (Australia)] (ORCID:0000000322269169), Sarkar, Arnab [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Kavli Institute for Astrophysics and Space Research] (ORCID:0000000252221337), Somboonpanyakul, Taweewat [Chulalongkorn Univ. (Thailand)] (ORCID:0000000335213631), Su, Yuanyuan [Univ. of Kentucky, Lexington, KY (United States)] (ORCID:0000000238861258). 2025-05-29. SZ–X-Ray Surface Brightness Fluctuations in the SPT-XMM Clusters. https://doi.org/10.3847/1538-4357%2Fadcd74

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

Dust Survival in Galactic Winds

This repository contains three-dimensional volumetric data from an Eulerian hydrodynamical simulation (conducted on a uniform Cartesian grid) generated by the Cholla hydrodynamics code. The datasets contain snapshots (full-grid, projections, and slices) in the HDF5 format of a multi-phase medium in which a hot, diffuse, dust-free background wind accelerates a cool, dense cloud of gas and dust. This scenario is intended to represent a supernova-driven galactic outflow, in which hot supernova winds are thought to accelerate cool interstellar medium material out of the galactic disk into the surrounding circumgalactic medium. There are three separate datasets for simulations corresponding to three cloud evolutionary scenarios: long-term cloud survival (surv), marginal cloud survival (disr), and cloud destruction (dest). Projection and slice images of the simulations are also included in this repository.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2026

Unraveling TeV halos with the Cherenkov Telescope Array

Pulsars are observed to emit bright and spatially extended gamma-ray emission at multi-TeV energies. These so-called "TeV halos" are now understood to be a nearly universal feature of middle-aged pulsars. However, many of the key physical processes that govern these systems, particularly those affecting particle diffusion, remain poorly constrained. We aim to evaluate the ability of the Cherenkov Telescope Array (CTA) to probe the physical properties of TeV halos, with a focus on the nearby and well-studied case of the Geminga pulsar. We simulate gamma-ray emission from various TeV halo models, incorporating different assumptions for the injected electron spectrum, spin-down evolution, and energy-dependent diffusion. These models are then used to forecast CTA's sensitivity to spectral and spatial differences, based on realistic mock observations and instrument response simulations. We find that CTA will be able to distinguish between a wide range of TeV halo models that are currently consistent with existing data. In particular, CTA observations can constrain the normalization, energy dependence, and spatial extent of the diffusion coefficient surrounding Geminga, as well as the spectral shape of the injected electron population.

79 ASTRONOMY AND ASTROPHYSICS↗