Julie Hlavacek-Larrondo

Probable Detection of a Cooler Gas Component in the Perseus Cluster with XRISM

Julian Meunier

Brian R. McNamara

A. Simionescu

François Mernier

Irina Zhuravleva

Congyao Zhang

Annie Heinrich

Frederick Scott Porter

John A. ZuHone

Elena Bellomi

Ian Drury

Megan E. Eckart

Ryuichi Fujimoto

Yutaka Fujita

Liyi Gu

Isamu Hatsukade

Yuto Ichinohe

Yoshiaki Kanemaru … (voir 19 de plus)

Takao Kitaguchi

Shunji Kitamoto

Shōgo Kobayashi

Takayoshi Kohmura

Hironori Matsumoto

Kyoko Matsushita

K. Migkas

Ikuyuki Mitsuishi

Koji Mori

Hiroshi Nakajima

Hirofumi Noda

Anna Ogorzałek

Naomi Ota

Lior Shefler

Nhut Truong

Ayşegül Tümer

Nagomi Uchida

Yuusuke Uchida

Shutaro Ueda

Abstract We present an analysis of the temperature structure of the Perseus cluster atmosphere using X-Ray Imaging and Spectroscopy Mission … (voir plus)(XRISM) Resolve observations. The average temperature rises from 3.3 keV near the nucleus of NGC 1275 to 8 keV at 10′ (210 kpc), which is consistent with Chandra and XMM measurements. The velocity and velocity dispersion profiles are broadly consistent with those in XRISM Collaboration et al. While the gas at altitudes beyond ∼60 kpc can be modeled as a single temperature plasma, we find evidence for more than one gas phase in the inner ∼60 kpc. The hotter gas component, traced primarily by the Fe He α line, has a velocity dispersion of ≲140 km s −1 . We detect a cooler, ∼1.87–2.43 keV, gas component with a velocity dispersion of ∼300–400 km s −1 , a bulk velocity of ∼21–213 km s −1 with respect to the central galaxy, and a mass of 8 × 10 9 –13 × 10 10 M ⊙ . These ranges reflect large systematic uncertainties associated with modeling spatial-spectral mixing and the bright central point source. Potential low energy gain variations may add additional uncertainties. The cooler component is identified by broad wings in prominent emission lines, most notably S Ly α and Fe He α . This cooler component’s Mach number ∼0.73–0.96 and nonthermal pressure fraction of ∼22.9%–33.7% are much higher than found for the hotter gas. The cooler gas may be associated with merging halos along the line of sight, which formed the cool, sloshing spiral and/or cooling gas being disturbed by the radio jets and lobes.

2026-09-07

Astrophysical Journal (publié)

High-spectral-resolution Observations of the [S II ] Emission-line Doublet in the Filamentary Nebula Surrounding NGC 1275

Carter Lee Rhea

Christoph Pfrommer

Greg L. Bryan

Megan E. Donahue

Alastair C. Edge

Andrew C. Fabian

M. McDonald

A. Richard-Laferrière

Laurie Rousseau-Nepton

G. Mark Voit

Norbert Werner

Abstract We analyze new high-spectral-resolution Spectromètre Imageur à Transformée de Fourier pour l’Etude en Long et en Large de raie… (voir plus)s d’Emission (SITELLE) observations ( R = λ /Δ λ = 7000) of the filamentary nebula surrounding NGC 1275, the central galaxy of the Perseus Cluster. We present here analysis of the [S ii ] λ 6716 and [S ii ] λ 6731 emission-line doublet, using its ratio to determine the electron density of the optically emitting filaments. We compare these measurements with electron densities derived from deep Chandra X-ray observations of the intracluster medium (ICM) to determine if any correlations in density can be found. We report the detection of a clear dichotomy between the outer filaments, displaying on average lower [S ii ] emission-line ratios of ∼1.1, and the inner filaments, displaying higher ratios of ∼1.3. These results indicate that most of the gaseous filaments lie close to the low-density threshold for the density measurement of ∼10 2 cm −3 . Using radial profiles, we find that the inner filaments have a roughly constant density, whereas the ICM density decreases with radius. In the outer filaments, we observe hints of local connections between the densities of the ICM and optical filaments, but no clear correlation seems to be observed overall. We also combined these density measurements with cold molecular CO gas observations to derive a relationship between temperature, density, and pressure for the multiphase environment surrounding NGC 1275. Finally, we investigated potential models to explain the observed density measurements and explored similar studies of filamentary nebulae around other central galaxies of cool-core galaxy clusters.

2026-08-24

Astrophysical Journal (publié)

JWST Reveals How Black Holes are Fed: Kiloparsec-scale Multiphase Filaments Feed Subkiloparsec Circumnuclear Disks

Hyunseop Choi

Minghao Guo

Mathieu Marquis

Olivia Pereira

G. Mark Voit

Loïc Albert

J. K. Barrera-Ballesteros

Rebecca Canning

Francesco D’Eugenio

Megan E. Donahue

A. C. Fabian

G. J. Ferland

John S. Gallagher

Marie-Lou Gendron-Marsolais

P. Guillard

Nina Hatch

Ralf Kotulla

Yuan Li

R. Maiolino … (voir 18 de plus)

Allison W. S. Man

M. McDonald

B R McNamara

Valeria Olivares

Marine Prunier

Michael Reefe

Christopher S. Reynolds

Carter Lee Rhea

A. Richard-Laferrière

H. R. Russell

P. Salomé

Ming Sun

Prathamesh Tamhane

Greg B Taylor

Auriane Thilloy

Grant R Tremblay

S A Walker

Abstract The Centaurus cluster is one of the most important archetypes of radio-mode active galactic nucleus (AGN) feedback, with its centra… (voir plus)l galaxy, NGC 4696, launching powerful jets that inflate X-ray cavities and regulate cooling and star formation. NGC 4696 lies within a spectacular multiphase nebula of filaments extending over tens of kiloparsecs and spanning 6 decades in temperature, from hot (10 8 K) X-ray-emitting plasma to cold molecular gas. Owing to its proximity, Hubble Space Telescope H α imaging reveals a striking S-shaped ionized-gas swirl within the black hole’s sphere of influence—the first such structure identified in a cluster core. Here we present the first JWST observations of NGC 4696 with NIRSpec, probing the inner 618 × 618 pc at 10 pc resolution. These data reveal that the ionized swirl is a rotating, multiphase circumnuclear disk (CND) physically and kinematically connected to the larger-scale filamentary network. This provides the long-sought missing link between kiloparsec-scale cooling flows and black hole accretion on 100 pc scales. Strikingly, the observed morphology and kinematics are reproduced by tailored magnetohydrodynamic simulations, in which fila

2026-07-13

Astrophysical Journal Letters (publié)

The Cluster Evolutionary Reference Ensemble at Low- <i>z</i> (CEREAL) Sample of Galaxy Clusters. I. X-Ray Morphological Properties and Demographics

L. V. White

Michael McDonald

S. J. Allen

Marshall W. Bautz

Michael S. Calzadilla

G. P. Garmire

Ralph Kraft

Adam B. Mantz

Taweewat Somboonpanyakul

Alexey Vikhlinin

Abstract With rapid improvements in the assembly of large samples of galaxy clusters, we are approaching the ability to study clusters at z … (voir plus)≳ 2. Evolutionary studies comparing these distant clusters to the clusters in our local Universe depend heavily on the reliability of low-redshift cluster samples, most of which are subject to X-ray selection effects, biasing them to relaxed, cool-core clusters. Here, we introduce the Cluster Evolutionary Reference Ensemble at Low- z (CEREAL) sample, composed of Chandra X-ray observations of 169 galaxy clusters that have been selected from the Planck Sunyaev–Zel’dovich catalog. CEREAL has a simple and well-understood selection function, spans an order of magnitude in mass at z ∼ 0.15, and has uniform, high-resolution X-ray follow-up. We present the full sample and provide results based on X-ray surface brightness properties, finding significantly more non-cool-core systems than in X-ray-selected samples. We use surface brightness concentration ( c SB ) as a proxy for cool-core strength and centroid shift ( w ) to measure dynamical state. Over the full sample, we find a cool-core ( c SB > 0.075) fraction of 0.3 9 − 0.04 + 0.04 , a strong cool-core ( c SB > 0.155) fraction of 0.1 3 − 0.03 + 0.03 , and a dynamically relaxed ( w < 0.01) frac

2026-03-26

Astrophysical Journal (publié)

SPT-CL J0417–4748: A Deep Chandra Study of a Relaxed Galaxy Cluster without Central Star Formation

Taweewat Somboonpanyakul

A. Mantz

S. W. Allen

Anthony M. Flores

R. Glenn Morris

Haley R. Stueber

L. E. Bleem

B. Floyd

Keunho Kim

Abstract We present an in-depth Chandra X-ray analysis of the galaxy cluster SPT-CL J0417−4748 (hereafter SPT J0417) at z = 0.58 with a fo… (voir plus)cus on its thermodynamic properties and the apparent absence of central star formation. Utilizing a total Chandra exposure of 103 ks, we find that the large-scale X-ray morphology is consistent with a dynamically relaxed cool-core system. The intracluster medium shows a central density of 0.08 ± 0.01 cm −3 , a central pseudoentropy of 2 6 − 5 + 6 keV cm 2 , and a central cooling time of 51 5 − 75 + 96 Myr, values typical of massive cool-core clusters. Despite these conditions, no evidence of recent or ongoing star formation is detected in the brightest cluster galaxy (BCG). Spectral energy di

2026-03-10

Astrophysical Journal (publié)

Probabilistic Interpolation of Sagittarius A*’s Multiwavelength Light Curves Using Diffusion Models

Gabriel Sasseville

Daryl Haggard

Alexandre Adam

Hadrien Paugnat

Gunther Witzel

Abstract Understanding the variability of Sagittarius A* (Sgr A*) requires coordinated, multiwavelength observations that span the electroma… (voir plus)gnetic spectrum. In this work, we focus on data from four key observatories: Chandra in the X-ray (2–8 keV), GRAVITY on the Very Large Telescope in the near-infrared (2.2 μ m), Spitzer in the infrared (4.5 μ m), and the Atacama Large Millimeter/submillimeter Array in the submillimeter (340 GHz). These multiband observations are essential for probing the physics of accretion and emission near the black hole’s event horizon, yet they suffer from irregular sampling, band-dependent noise, and substantial data gaps. These limitations complicate efforts to robustly identify flares and measure cross-band time lags, key diagnostics of the physical processes driving variability. To address this challenge, we introduce a diffusion-based generative model, for interpolating sparse, multivariate astrophysical time series. This represents the first application of score-based diffusion models to astronomical time series. We also present the first transformer-based model for light-curve reconstruction that includes calibrated uncertainty estimates. The models are trained on simulated light curves constructed to match the statistical and observational characteristics of real Sgr A* data. These simulations capture correlated multiband variability, realistic observation cadences, and wavelength-specific noise. We compare our models against a multi-output Gaussian process. The diffusion model achieves superior accuracy and competitive calibration across both simulated and real datasets, demonstrating the promise of diffusion models for high-fidelity, uncertainty-aware reconstruction of multiwavelength variability in Sgr A*.

2026-02-02

Astrophysical Journal (publié)

Mapping the Perseus galaxy cluster with XRISM

Congyao Zhang

Irina Zhuravleva

Hannah McCall

Elena Bellomi

Nhut Truong

John ZuHone

Eugene Churazov

Megan E. Eckart

Yutaka Fujita

Yuto Ichinohe

Maxim Markevitch

Kyoko Matsushita

François Mernier

Eric D. Miller

Koji Mori

Hiroshi Nakajima

Anna Ogorzalek

Frederick S. Porter

Ayşegül Tümer … (voir 3 de plus)

Shutaro Ueda

Norbert Werner

Annie Heinrich

We present extended gas kinematic maps of the Perseus cluster based on a combination of five new XRISM/Resolve pointings observed in 2025 wi… (voir plus)th four performance verification datasets from 2024, totaling a net exposure of 745 ks. To date, Perseus remains the only cluster that has been extensively mapped out to ≃0.7 r 2500 by XRISM/Resolve, while simultaneously offering sufficient spatial resolution to resolve gaseous substructures driven by mergers and active galactic nucleus (AGN) feedback. Our observations cover multiple radial directions and a broad range of dynamical scales, enabling us to characterize the kinematic properties of the intracluster medium up to a scale of ∼500 kpc. In the measurements, we detected high-velocity dispersions (≃300km s −1 ) in the eastern region of the cluster that are spatially coincident with the extended X-ray surface brightness excess and correspond to a nonthermal pressure fraction of ≃7 − 13%. The velocity field outside the AGN-dominant region can be effectively described by a single, large-scale kinematic driver based on the velocity structure function, which statistically favors an energy injection scale of at least a few hundred kpc. The estimated turbulent dissipation energy is comparable to the gravitational potential energy released by a recent merger, implying a significant role of turbulent cascade in the merger energy conversion. In the bulk velocity field, we observed a dipole-like pattern along the east-west direction with an amplitude of ≃ ± 200 − 300 km s −1 , indicating rotational motions induced by the recent merger event. This feature constrains the viewing direction to ≃30° −50° relative to the normal of the merger plane. Our hydrodynamic simulations suggest that Perseus has experienced at least two energetic mergers since redshift z ∼ 1, the most recent of which is associated with the radio galaxy IC310, in agreement with recent SRG/eROSITA findings. This study showcases exciting scientific opportunities for future missions with high-resolution spectroscopic capabilities (e.g., HUBS, LEM, and NewAthena).

2026-01-18

Astronomy & Astrophysics (publié)

Disentangling AGN Feedback and Sloshing in the Perseus Cluster with XRISM: Insights from Simulations

Elena Bellomi

John A. ZuHone

Nhut Truong

Irina Zhuravleva

Rainer Weinberger

Christoph Pfrommer

Congyao Zhang

Annie Heinrich

Mateusz Ruszkowski

Brian McNamara

M. Gendron-Marsolais

High-resolution X-ray spectroscopy with XRISM has revealed complex, non-monotonic velocity dispersion profiles in the Perseus cluster, point… (voir plus)ing to a complex interplay between at least two physical drivers of motions caused by dynamical processes within the intracluster medium (ICM). To further explore this conclusion, we perform a suite of idealized, controlled simulations targeting the relative roles of merger-induced sloshing and active galactic nucleus (AGN) feedback. Our models systematically isolate and combine these mechanisms to predict observable velocity profiles and X-ray line shapes, providing direct comparison to XRISM and Hitomi data. We find that neither sloshing nor AGN activity alone can reproduce the observed velocity dispersion profile; only their combined action matches the elevated dispersions both at the cluster core and outskirts. Power-spectrum analysis reveals distinct spatial signatures: sloshing generates large-scale coherent motions, while AGN feedback injects turbulence and broadens the velocity spectrum at small scales, especially in the core. By forward-modeling spectral line profiles, we show how these dynamics imprint unique observational signatures on X-ray emission. Our results underscore the necessity of accounting for both large-scale and small-scale drivers of gas motions in the ICM when interpreting high-resolution spectroscopic data, and provide guidance for the analysis of forthcoming XRISM observations.

2025-12-13

arXiv (prépublication)

Observations of AGN-driven feedback: dynamics and ionization of the filaments in M87

Camille Poitras

Marie-Lou Gendron-Marsolais

Valeria Olivares

Yuan Li

Adrien Picquenot

Aurora Simionescu

Matteo Fossati

Alessandro Boselli

Laura Hermosa Muñoz

Sara Cazzoli

Annabelle Richard-Laferrière

We present a comprehensive kinematic and ionization analysis of the warm ionized filaments (…

2025-11-10

Monthly Notices of the Royal Astronomical Society (publié)

Massive Extremely High-velocity Outflow in the Quasar J164653.72+243942.2

Paola Rodríguez Hidalgo

Hyunseop Choi (최현섭)

Patrick B. Hall

Karen M. Leighly

Liliana Flores

Mikel M. Charles

Cora DeFrancesco

Laurence Perreault-Levasseur

We present the analysis of one of the most extreme quasar outflows found to date in our survey of extremely high velocity outflows (EHVO). J… (voir plus)164653.72+243942.2 (z ~ 3.04) shows variable CIV1548,1551 absorption at speeds larger than 0.1c, accompanied by SiIV, NV and Lya, and disappearing absorption at lower speeds. We perform absorption measurements using the Apparent Optical Depth method and SimBAL. We find the absorption to be very broad (Δv ~35,100 km/s in the first epoch and ~13,000 km/s in the second one) and fast (vmax ~ -50,200 km/s and -49,000 km/s, respectively). We measure large column densities (

2025-09-03

The Astrophysical Journal (publié)