Cosmological hydrodynamical simulations of galaxy clusters: X-ray scaling relations and their evolution

AbstractRecent advances in X-ray and microwave observations have provided unprecedented insights into the structure and evolution of the hot X-ray emitting plasma from their cores to the virialization region in outskirts of galaxy clusters. Recent Sunyaev-Zel'dovich (SZ) surveys (ACT, Planck, SPT) have provided new cluster catalogs, significantly expanding coverage of the mass-redshift plane, whileChandraandXMM-NewtonX-ray follow-up programs have improved our understanding of cluster physics and evolution as well as the surveys themselves. However, the current cluster-based cosmological constraints are still limited by uncertainties in cluster astrophysics. In order to exploit the statistical power of the current and upcoming X-ray and microwave cluster surveys, it is critical to improve our understanding of the structure and evolution of the hot X-ray emitting intracluster medium (ICM). In this session, we discussed recent advances in observations and simulations of galaxy clusters, with highlights on (i) the evolution of ICM profiles and scaling relations, (ii) physical processes operating in the outskirts of galaxy clusters, and (iii) impact of mergers on the ICM structure in groups and clusters.

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The relation between the diffuse X-ray luminosity and the radio power of the central AGN in galaxy groups

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2049 ◽

2020 ◽

Vol 497 (2) ◽

pp. 2163-2174

Author(s):

T Pasini ◽

M Brüggen ◽

F de Gasperin ◽

L Bîrzan ◽

E O’Sullivan ◽

...

Keyword(s):

Radio Emission ◽

Galaxy Clusters ◽

Active Galactic Nucleus ◽

Statistical Tests ◽

Control Sample ◽

Radio Galaxies ◽

Very Large Array ◽

X Ray ◽

Galaxy Groups ◽

Hydrodynamical Simulations

ABSTRACT Our understanding of how active galactic nucleus feedback operates in galaxy clusters has improved in recent years owing to large efforts in multiwavelength observations and hydrodynamical simulations. However, it is much less clear how feedback operates in galaxy groups, which have shallower gravitational potentials. In this work, using very deep Very Large Array and new MeerKAT observations from the MIGHTEE survey, we compiled a sample of 247 X-ray selected galaxy groups detected in the COSMOS field. We have studied the relation between the X-ray emission of the intra-group medium and the 1.4 GHz radio emission of the central radio galaxy. For comparison, we have also built a control sample of 142 galaxy clusters using ROSAT and NVSS data. We find that clusters and groups follow the same correlation between X-ray and radio emission. Large radio galaxies hosted in the centres of groups and merging clusters increase the scatter of the distribution. Using statistical tests and Monte Carlo simulations, we show that the correlation is not dominated by biases or selection effects. We also find that galaxy groups are more likely than clusters to host large radio galaxies, perhaps owing to the lower ambient gas density or a more efficient accretion mode. In these groups, radiative cooling of the intra-cluster medium could be less suppressed by active galactic nucleus heating. We conclude that the feedback processes that operate in galaxy clusters are also effective in groups.

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X-ray calibration of Sunyaev-Zel’dovich scaling relations with the ACCEPT catalogue of galaxy clusters observed by Chandra

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2011.19562.x ◽

2011 ◽

Vol 418 (2) ◽

pp. 1089-1101 ◽

Cited By ~ 19

Author(s):

B. Comis ◽

M. De Petris ◽

A. Conte ◽

L. Lamagna ◽

S. De Gregori

Keyword(s):

Galaxy Clusters ◽

Scaling Relations ◽

X Ray

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Athena X-IFU synthetic observations of galaxy clusters to probe the chemical enrichment of the Universe

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833927 ◽

2018 ◽

Vol 620 ◽

pp. A173 ◽

Cited By ~ 12

Author(s):

E. Cucchetti ◽

E. Pointecouteau ◽

P. Peille ◽

N. Clerc ◽

E. Rasia ◽

...

Keyword(s):

Galaxy Clusters ◽

Chemical Elements ◽

Cosmic Time ◽

Initial Mass Function ◽

Metal Production ◽

X Ray ◽

Chemical Enrichment ◽

Spatially Resolved ◽

Hydrodynamical Simulations ◽

The Universe

Answers to the metal production of the Universe can be found in galaxy clusters, notably within their intra-cluster medium (ICM). The X-ray Integral Field Unit (X-IFU) on board the next-generation European X-ray observatory Athena (2030s) will provide the necessary leap forward in spatially-resolved spectroscopy required to disentangle the intricate mechanisms responsible for this chemical enrichment. In this paper, we investigate the future capabilities of the X-IFU in probing the hot gas within galaxy clusters. From a test sample of four clusters extracted from cosmological hydrodynamical simulations, we present comprehensive synthetic observations of these clusters at different redshifts (up to z ≤ 2) and within the scaled radius R500 performed using the instrument simulator SIXTE. Through 100 ks exposures, we demonstrate that the X-IFU will provide spatially resolved mapping of the ICM physical properties with little to no biases (⪅5%) and well within statistical uncertainties. The detailed study of abundance profiles and abundance ratios within R500 also highlights the power of the X-IFU in providing constraints on the various enrichment models. From synthetic observations out to z = 2, we have also quantified its ability to track the chemical elements across cosmic time with excellent accuracy, and thereby to investigate the evolution of metal production mechanisms as well as the link to the stellar initial mass-function. Our study demonstrates the unprecedented capabilities of the X-IFU of unveiling the properties of the ICM but also stresses the data analysis challenges faced by future high-resolution X-ray missions such as Athena.

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Probing cosmic isotropy with a new X-ray galaxy cluster sample through the LX–T scaling relation

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936602 ◽

2020 ◽

Vol 636 ◽

pp. A15 ◽

Cited By ~ 16

Author(s):

K. Migkas ◽

G. Schellenberger ◽

T. H. Reiprich ◽

F. Pacaud ◽

M. E. Ramos-Ceja ◽

...

Keyword(s):

Galaxy Clusters ◽

Statistical Significance ◽

Cosmological Parameters ◽

Galaxy Cluster ◽

Temperature Measurements ◽

Joint Analysis ◽

Scaling Relations ◽

Exact Nature ◽

X Rays ◽

X Ray

The isotropy of the late Universe and consequently of the X-ray galaxy cluster scaling relations is an assumption greatly used in astronomy. However, within the last decade, many studies have reported deviations from isotropy when using various cosmological probes; a definitive conclusion has yet to be made. New, effective and independent methods to robustly test the cosmic isotropy are of crucial importance. In this work, we use such a method. Specifically, we investigate the directional behavior of the X-ray luminosity-temperature (LX–T) relation of galaxy clusters. A tight correlation is known to exist between the luminosity and temperature of the X-ray-emitting intracluster medium of galaxy clusters. While the measured luminosity depends on the underlying cosmology through the luminosity distance DL, the temperature can be determined without any cosmological assumptions. By exploiting this property and the homogeneous sky coverage of X-ray galaxy cluster samples, one can effectively test the isotropy of cosmological parameters over the full extragalactic sky, which is perfectly mirrored in the behavior of the normalization A of the LX–T relation. To do so, we used 313 homogeneously selected X-ray galaxy clusters from the Meta-Catalogue of X-ray detected Clusters of galaxies. We thoroughly performed additional cleaning in the measured parameters and obtain core-excised temperature measurements for all of the 313 clusters. The behavior of the LX–T relation heavily depends on the direction of the sky, which is consistent with previous studies. Strong anisotropies are detected at a ≳4σ confidence level toward the Galactic coordinates (l, b) ∼ (280°, − 20°), which is roughly consistent with the results of other probes, such as Supernovae Ia. Several effects that could potentially explain these strong anisotropies were examined. Such effects are, for example, the X-ray absorption treatment, the effect of galaxy groups and low redshift clusters, core metallicities, and apparent correlations with other cluster properties, but none is able to explain the obtained results. Analyzing 105 bootstrap realizations confirms the large statistical significance of the anisotropic behavior of this sky region. Interestingly, the two cluster samples previously used in the literature for this test appear to have a similar behavior throughout the sky, while being fully independent of each other and of our sample. Combining all three samples results in 842 different galaxy clusters with luminosity and temperature measurements. Performing a joint analysis, the final anisotropy is further intensified (∼5σ), toward (l, b) ∼ (303°, − 27°), which is in very good agreement with other cosmological probes. The maximum variation of DL seems to be ∼16 ± 3% for different regions in the sky. This result demonstrates that X-ray studies that assume perfect isotropy in the properties of galaxy clusters and their scaling relations can produce strongly biased results whether the underlying reason is cosmological or related to X-rays. The identification of the exact nature of these anisotropies is therefore crucial for any statistical cluster physics or cosmology study.

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The cosmological analysis of X-ray cluster surveys

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731445 ◽

2018 ◽

Vol 614 ◽

pp. A72 ◽

Cited By ~ 1

Author(s):

A. Valotti ◽

M. Pierre ◽

A. Farahi ◽

A. Evrard ◽

L. Faccioli ◽

...

Keyword(s):

Cosmological Parameters ◽

Scaling Relations ◽

Temperature Relation ◽

Local Scaling ◽

X Ray ◽

Mass Size ◽

Final Error ◽

Hydrodynamical Simulations ◽

The Impact ◽

Size Relation

Context. This paper is the fourth of a series evaluating the ASpiX cosmological method, based on X-ray diagrams, which are constructed from simple cluster observable quantities, namely: count rate (CR), hardness ratio (HR), core radius (rc), and redshift. Aims. Following extensive tests on analytical toy catalogues (Paper III), we present the results of a more realistic study over a 711 deg2 template-based maps derived from a cosmological simulation. Methods. Dark matter haloes from the Aardvark simulation have been ascribed luminosities, temperatures, and core radii, using local scaling relations and assuming self-similar evolution. The predicted X-ray sky-maps were converted into XMM event lists, using a detailed instrumental simulator. The XXL pipeline runs on the resulting sky images, produces an observed cluster catalogue over which the tests have been performed. This allowed us to investigate the relative power of various combinations of the CR, HR, rc, and redshift information. Two fitting methods were used: a traditional Markov chain Monte Carlo (MCMC) approach and a simple minimisation procedure (Amoeba) whose mean uncertainties are a posteriori evaluated by means of synthetic catalogues. The results were analysed and compared to the predictions from the Fisher analysis (FA). Results. For this particular catalogue realisation, assuming that the scaling relations are perfectly known, the CR-HR combination gives σ8 and Ωm at the 10% level, while CR-HR-rc-z improves this to ≤3%. Adding a second HR improves the results from the CR-HR1-rc combination, but to a lesser extent than when adding the redshift information. When all coefficients of the mass-temperature relation (M-T, including scatter) are also fitted, the cosmological parameters are constrained to within 5–10% and larger for the M-T coefficients (up to a factor of two for the scatter). The errors returned by the MCMC, those by Amoeba and the FA predictions are in most cases in excellent agreement and always within a factor of two. We also study the impact of the scatter of the mass-size relation (M-Rc) on the number of detected clusters: for the cluster typical sizes usually assumed, the larger the scatter, the lower the number of detected objects. Conclusions. The present study confirms and extends the trends outlined in our previous analyses, namely the power of X-ray observable diagrams to successfully and easily fit at the same time, the cosmological parameters, cluster physics, and the survey selection, by involving all detected clusters. The accuracy levels quoted should not be considered as definitive. A number of simplifying hypotheses were made for the testing purpose, but this should affect any method in the same way. The next publication will consider in greater detail the impact of cluster shapes (selection and measurements) and of cluster physics on the final error budget by means of hydrodynamical simulations.

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Precessing AGN jets, bubbles and cooling flows

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311014839 ◽

2010 ◽

Vol 6 (S275) ◽

Author(s):

D. Falceta-Gonçalves ◽

A. Caproni ◽

Z. Abraham ◽

E. M. de Gouveia Dal Pino ◽

D. M. Teixeira

Keyword(s):

Galaxy Clusters ◽

Flow Problem ◽

X Rays ◽

Intracluster Medium ◽

X Ray ◽

Cooling Flows ◽

Cooling Flow ◽

Central Regions ◽

Multiple Bubbles ◽

Hydrodynamical Simulations

AbstractSeveral galaxy clusters are known to present multiple and misaligned pairs of cavities seen in X-rays, as well as twisted kiloparsec-scale jets at radio wavelengths. It suggests that the AGN precessing jets play a role in the formation of the misaligned bubbles. Also, X-ray spectra reveal that typically these systems are also able to supress cooling flows, predicted theoretically. The absence of cooling flows in galaxy clusters has been a mistery for many years since numerical simulations and analytical studies suggest that AGN jets are highly energetic, but are unable to redistribute it at all directions. We performed 3D hydrodynamical simulations of the interaction between a precessing AGN jet and the warm intracluster medium plasma, in which dynamics is coupled to a NFW dark matter gravitational potential. Radiative cooling has been taken into account and the cooling flow problem was studied. We found that precession is responsible for multiple pairs of bubbles, as observed. The misaligned bubbles rise up to scales of tens of kiloparsecs, where the thermal energy released by the jets are redistributed. After ~150 Myrs, the temperature of the gas within the cavities is kept of order of ~107 K, while the denser plasma of the intracluster medium at the central regions reaches T ~ 105 K. The existence of multiple bubbles, at diferent directions, results in an integrated temperature along the line of sight much larger than the simulations of non-precessing jets. This result is in agreement with the observations. The simulations reveal that the cooling flows cessed ~50–70 Myr after the AGN jets are started.

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