Article
Astronomy & Astrophysics
Uri Keshet, Itay Raveh, Yossi Naor
Summary: A clump moving through the intracluster medium of a galaxy cluster can create a bow shock trailed by a bullet-like core. The presence of dark matter can explain certain features seen in X-ray imaging, providing a unique probe for studying offset, collisionless dark matter.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
D. Eckert, S. Ettori, A. Robertson, R. Massey, E. Pointecouteau, D. Harvey, I. G. McCarthy
Summary: The distribution of dark matter in the cold dark matter paradigm fits well with the Einasto profile, while self-interacting dark matter leads to flatter mass density profiles. Researchers measured the structural properties of massive galaxy clusters and found that the measurements are consistent with the predictions of the cold dark matter paradigm. The self-interaction cross section of dark matter is found to be lower than what is required to solve the core-cusp problem in dwarf spheroidal galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Uri Keshet, Itay Raveh, Arka Ghosh
Summary: Well-resolved galaxy clusters often exhibit a large-scale quasi-spiral structure in density and temperature fields, characterized by a tangential discontinuity called a cold front, superimposed on a universal radial entropy profile. This spiral structure provides a natural solution for the mixed intracluster medium, confining the buoyant or heavy plasma phases. The solution persists even in the presence of rotation and can accommodate both inflow and outflow.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Efrain Gatuzz, J. S. Sanders, R. Canning, K. Dennerl, A. C. Fabian, C. Pinto, H. Russell, T. Tamura, S. A. Walker, J. ZuHone
Summary: We present a detailed analysis of the velocity structure of the Centaurus cluster using XMM-Newton observations. The velocity structure of the intracluster medium is similar to the velocity structure of the main galaxies, and the cold fronts likely move in a plane perpendicular to our line of sight with low velocity. Additionally, the kinetic component contributes less than 25% to the total energetic budget for a radius larger than 30 kpc.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. Andreon, C. Romero, H. Aussel, T. Bhandarkar, M. Devlin, S. Dicker, B. Ladjelate, I Lowe, B. Mason, T. Mroczkowski, A. Raichoor, C. Sarazin, G. Trinchieri
Summary: In this study, we investigate the properties of the intracluster medium (ICM) in the galaxy cluster JKCS 041 at z = 1.803. By conducting a 28-hour Sunyaev-Zel'dovich (SZ) observation using the MUSTANG-2 instrument, we are able to detect JKCS 041, despite its intrinsic faintness compared to other SZ-detected clusters. The SZ peak of this cluster is found to be offset from the X-ray center, indicating the effect of a major merger. Moreover, JKCS 041 exhibits a lower central pressure and Compton Y compared to local ICM-selected clusters, which can be attributed to its ongoing assembly process and potential biases in the local samples.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
E. W. Upsdell, P. A. Giles, A. K. Romer, R. Wilkinson, D. J. Turner, M. Hilton, E. Rykoff, A. Farahi, S. Bhargava, T. Jeltema, M. Klein, A. Bermeo, C. A. Collins, L. Ebrahimpour, D. Hollowood, R. G. Mann, M. Manolopoulou, C. J. Miller, P. J. Rooney, Martin Sahlen, J. P. Stott, P. T. P. Viana, S. Allam, O. Alves, D. Bacon, E. Bertin, S. Bocquet, D. Brooks, D. L. Burke, M. Carrasco Kind, J. Carretero, M. Costanzi, L. N. da Costa, M. E. S. Pereira, J. De Vicente, S. Desai, H. T. Diehl, J. P. Dietrich, S. Everett, I Ferrero, J. Frieman, J. Garcia-Bellido, D. W. Gerdes, G. Gutierrez, S. R. Hinton, K. Honscheid, D. J. James, K. Kuehn, N. Kuropatkin, M. Lima, J. L. Marshall, J. Mena-Fernandez, F. Menanteau, R. Miquel, J. J. Mohr, R. L. C. Ogando, A. Pieres, M. Raveri, M. Rodriguez-Monroy, E. Sanchez, V Scarpine, I Sevilla-Noarbe, M. Smith, E. Suchyta, M. E. C. Swanson, G. Tarle, C. To, N. Weaverdyck, J. Weller, P. Wiseman
Summary: We compare two samples of galaxy clusters from different sky surveys and techniques. One sample is optically selected using the redMaPPer algorithm from Dark Energy Survey observations, while the other is X-ray selected from XMM observations. The two samples show consistent results in the scaling relations of X-ray luminosity-temperature, X-ray luminosity-richness, and X-ray temperature-richness. However, there is tentative evidence for a steepening slope of the relation in low richness systems for the X-ray-selected sample.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Philipp Kempski, Eliot Quataert, Jonathan Squire
Summary: Active Galactic Nuclei (AGN) are believed to prevent gas cooling in galaxy clusters, but the transport and thermalization of this energy in the Intracluster Medium (ICM) is unclear. Recent research shows that cosmic ray streaming destabilizes sound waves and pressure-balanced waves in dilute ICM plasmas, which is termed as the CR buoyancy instability (CRBI). This instability, along with heat-flux-driven buoyancy instability (HBI) and magneto-thermal instability (MTI), contributes to the observed sound waves, weak shocks, and turbulence in galaxy clusters. The results suggest that CR-driven instabilities may play a role in redistributing AGN energy throughout the clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jacob Svensmark, Steen H. Hansen, Davide Martizzi, Ben Moore, Romaine Tessier
Summary: This study introduces a new method to infer the dynamical property of dark matter, namely velocity anisotropy. The results show that the velocity anisotropy of DM in bright galaxy clusters is consistent with numerical simulations, supporting the collisionless nature of DM.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Veronica Biffi, John A. ZuHone, Tony Mroczkowski, Esra Bulbul, William Forman
Summary: High-resolution X-ray spectroscopy enables the measurement of gas velocities in galaxy clusters and the detection of multiple velocity components or gradients. X-ray calorimeters can detect non-Gaussian features in X-ray emission lines, but larger collecting areas and high signal-to-noise ratios are required for measurements in low surface brightness regions. Simulations can be used to study temperature and velocity gradients in galaxy clusters, but the uncertainty in velocity dispersion is significant.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Hideki Tanimura, Marian Douspis, Nabila Aghanim, Joseph Kuruvilla
Summary: In this study, we explored possible solutions to the S-8 tension by extending the standard ΛCDM cosmological model to include decay of dark matter. We tested two decay scenarios: decay into noninteracting dark radiation and decay into warm dark matter and dark radiation. By combining high and low-redshift measurements, our analysis showed that the second decay scenario provides a slightly better resolution to the S-8 tension, with a lower bound on the decay lifetime of approximately 24 Gyr at 95% confidence level.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Chong Ge, Rongxin Luo, Ming Sun, Masafumi Yagi, Pavel Jachym, Alessandro Boselli, Matteo Fossati, Paul E. J. Nulsen, Craig Sarazin, Tim Edge, Giuseppe Gavazzi, Massimo Gaspari, Jin Koda, Yutaka Komiyama, Michitoshi Yoshida
Summary: Recent studies have highlighted the significance of intracluster medium (ICM) clumping and discovered an isolated cloud in the nearby A1367 cluster, suggesting that stripped interstellar medium (ISM) can induce ICM inhomogeneities. This example indicates that ICM clumps may be multiphase in nature and can be traced in H alpha, implying potential for future investigations using H alpha surveys to probe ICM clumping and turbulence.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
X. Zhang, A. Simionescu, F. Gastaldello, D. Eckert, L. Camillini, R. Natale, M. Rossetti, G. Brunetti, H. Akamatsu, A. Botteon, R. Cassano, V. Cuciti, L. Bruno, T. W. Shimwell, A. Jones, J. S. Kaastra, S. Ettori, M. Brueggen, F. de Gasperin, A. Drabent, R. J. van Weeren, H. J. A. Roettgering
Summary: By analyzing the data from the LOFAR Two-metre Sky Survey (LoTSS-DR2), the study investigates the relationship between extended radio sources and the dynamic states of galaxy clusters. It finds a correlation between intracluster medium turbulence and radio halos, supporting the turbulent (re)acceleration scenario. Additionally, a new quantity [k(B)T center dot Y-X](rRH) is introduced, which is strongly correlated with radio halo power.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Micheli T. Moura, Rubens E. G. Machado, Rogerio Monteiro-Oliveira
Summary: Cluster mergers are important for studying dark matter and intracluster gas behavior, with dissociative collisions being able to separate gas from dark matter. Abell 2034, at z = 0.114, consists of two substructures with a mass ratio of about 1:2.2, showing clear dissociative features observed through X-rays and gravitational lensing, with the X-ray emission peak offcentered from the dark matter peak.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Physics, Multidisciplinary
Antonio Ambrosone, Marco Chianese, Damiano F. G. Fiorillo, Antonio Marinelli, Gennaro Miele
Summary: Starburst galaxies are potential sources of high-energy gamma rays, and their cosmic-ray spectrum distortion can be indirectly observed. Current data provide tight bounds on the cross section between protons and dark matter, while future measurements are expected to significantly improve these limits.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Moritz S. Fischer, Nils-Henrik Durke, Katharina Hollingshausen, Claudius Hammer, Marcus Brueggen, Klaus Dolag
Summary: Mergers of galaxy clusters are useful for studying dark matter physics, and we investigated the influence of the intracluster medium (ICM) on dark matter-galaxy offsets in self-interacting dark matter models. Our simulations showed that the ICM has little effect on initial offsets, but can amplify them at later stages. We also found that different dark matter models affect the distribution of dark matter, as well as galaxies and the ICM.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)