An X-Ray–Selected Galaxy Cluster at [CLC][ITAL]z[/ITAL][/CLC] = 1.26

AbstractXDCPJ0044.0-2033 is one of the most massive galaxy cluster at z ∼1.6, for which a wealth of multi-wavelength photometric and spectroscopic data have been collected during the last years. I have reported on the properties of the galaxy members in the very central region (∼ 70kpc × 70kpc) of the cluster, derived through deep HST photometry, SINFONI and KMOS IFU spectroscopy, together with Chandra X-ray, ALMA and JVLA radio data.In the core of the cluster, we have identified two groups of galaxies (Complex A and Complex B), seven of them confirmed to be cluster members, with signatures of ongoing merging. These galaxies show perturbed morphologies and, three of them show signs of AGN activity. In particular, two of them, located at the center of each complex, have been found to host luminous, obscured and highly accreting AGN (λ = 0.4−0.6) exhibiting broad Hα line. Moreover, a third optically obscured type-2 AGN, has been discovered through BPT diagram in Complex A. The AGN at the center of Complex B is detected in X-ray while the other two, and their companions, are spatially related to radio emission. The three AGN provide one of the closest AGN triple at z > 1 revealed so far with a minimum (maximum) projected distance of 10 kpc (40 kpc). The discovery of multiple AGN activity in a highly star-forming region associated to the crowded core of a galaxy cluster at z ∼ 1.6, suggests that these processes have a key role in shaping the nascent Brightest Cluster Galaxy, observed at the center of local clusters. According to our data, all galaxies in the core of XDCPJ0044.0-2033 could form a BCG of M* ∼ 1012Mȯ hosting a BH of 2 × 108−109Mȯ, in a time scale of the order of 2.5 Gyrs.

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Reconciling galaxy cluster shapes, measured by theorists versus observers

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3193 ◽

2020 ◽

Vol 500 (2) ◽

pp. 2627-2644

Author(s):

David Harvey ◽

Andrew Robertson ◽

Sut-Ieng Tam ◽

Mathilde Jauzac ◽

Richard Massey ◽

...

Keyword(s):

Hubble Space Telescope ◽

Orientation Angle ◽

Galaxy Cluster ◽

Galactic Nuclei ◽

Weak Lensing ◽

Strongly Correlated ◽

The Bahamas ◽

Cluster Galaxy ◽

Moments Of Inertia ◽

X Ray

ABSTRACT If properly calibrated, the shapes of galaxy clusters can be used to investigate many physical processes: from feedback and quenching of star formation, to the nature of dark matter. Theorists frequently measure shapes using moments of inertia of simulated particles’. We instead create mock (optical, X-ray, strong-, and weak-lensing) observations of the 22 most massive ($\sim 10^{14.7}\, \mathrm{ M}_\odot$) relaxed clusters in the BAHAMAS simulations. We find that observable measures of shape are rounder. Even when moments of inertia are projected into 2D and evaluated at matched radius, they overestimate ellipticity by 56 per cent (compared to observable strong lensing) and 430 per cent (compared to observable weak lensing). Therefore, we propose matchable quantities and test them using observations of eight relaxed clusters from the Hubble Space Telescope (HST) and Chandra X-Ray Observatory. We also release our HST data reduction and lensing analysis software to the community. In real clusters, the ellipticity and orientation angle at all radii are strongly correlated. In simulated clusters, the ellipticity of inner (<rvir/20) regions becomes decoupled: for example, with greater misalignment of the central cluster galaxy. This may indicate overly efficient implementation of feedback from active galactic nuclei. Future exploitation of cluster shapes as a function of radii will require better understanding of core baryonic processes. Exploitation of shapes on any scale will require calibration on simulations extended all the way to mock observations.

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Weak lensing calibration of mass bias in the REFLEX+BCS X-ray galaxy cluster catalogue

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stw3322 ◽

2016 ◽

Vol 466 (3) ◽

pp. 3663-3673 ◽

Cited By ~ 12

Author(s):

Melanie Simet ◽

Nicholas Battaglia ◽

Rachel Mandelbaum ◽

Uroš Seljak

Keyword(s):

Galaxy Cluster ◽

Weak Lensing ◽

X Ray ◽

Mass Bias

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Anisotropy of the galaxy cluster X-ray luminosity–temperature relation

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731222 ◽

2018 ◽

Vol 611 ◽

pp. A50 ◽

Cited By ~ 5

Author(s):

Konstantinos Migkas ◽

Thomas H. Reiprich

Keyword(s):

Galaxy Clusters ◽

Statistical Significance ◽

Cosmological Parameters ◽

Galaxy Cluster ◽

Luminosity Distance ◽

Temperature Relation ◽

X Ray ◽

Two Samples ◽

The Galaxy ◽

Group A

We introduce a new test to study the cosmological principle with galaxy clusters. Galaxy clusters exhibit a tight correlation between the luminosity and temperature of the X-ray-emitting intracluster medium. While the luminosity measurement depends on cosmological parameters through the luminosity distance, the temperature determination is cosmology-independent. We exploit this property to test the isotropy of the luminosity distance over the full extragalactic sky, through the normalization a of the LX–T scaling relation and the cosmological parameters Ωm and H0. To this end, we use two almost independent galaxy cluster samples: the ASCA Cluster Catalog (ACC) and the XMM Cluster Survey (XCS-DR1). Interestingly enough, these two samples appear to have the same pattern for a with respect to the Galactic longitude. More specifically, we identify one sky region within l ~ (−15°, 90°) (Group A) that shares very different best-fit values for the normalization of the LX–T relation for both ACC and XCS-DR1 samples. We use the Bootstrap and Jackknife methods to assess the statistical significance of these results. We find the deviation of Group A, compared to the rest of the sky in terms of a, to be ~2.7σ for ACC and ~3.1σ for XCS-DR1. This tension is not significantly relieved after excluding possible outliers and is not attributed to different redshift (z), temperature (T), or distributions of observable uncertainties. Moreover, a redshift conversion to the cosmic microwave background (CMB) frame does not have an important impact on our results. Using also the HIFLUGCS sample, we show that a possible excess of cool-core clusters in this region, is not able to explain the obtained deviations. Furthermore, we tested for a dependence of the results on supercluster environment, where the fraction of disturbed clusters might be enhanced, possibly affecting the LX–T relation. We indeed find a trend in the XCS-DR1 sample for supercluster members to be underluminous compared to field clusters. However, the fraction of supercluster members is similar in the different sky regions, so this cannot explain the observed differences, either. Constraining Ωm and H0 via the redshift evolution of LX–T and the luminosity distance via the flux–luminosity conversion, we obtain approximately the same deviation amplitudes as for a. It is interesting that the general observed behavior of Ωm for the sky regions that coincide with the CMB dipole is similar to what was found with other cosmological probes such as supernovae Ia. The reason for this behavior remains to be identified.

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Constraining the dark energy with galaxy cluster x-ray data

Physical Review D ◽

10.1103/physrevd.68.023510 ◽

2003 ◽

Vol 68 (2) ◽

Cited By ~ 86

Author(s):

J. A. S. Lima ◽

J. V. Cunha ◽

J. S. Alcaniz

Keyword(s):

Dark Energy ◽

Galaxy Cluster ◽

X Ray

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An improved deprojection and PSF-deconvolution technique for galaxy-cluster X-ray surface-brightness profiles

Astronomy and Astrophysics ◽

10.1051/0004-6361:20065795 ◽

2006 ◽

Vol 459 (3) ◽

pp. 1007-1019 ◽

Cited By ~ 35

Author(s):

J. H. Croston ◽

M. Arnaud ◽

E. Pointecouteau ◽

G. W. Pratt

Keyword(s):

Surface Brightness ◽

Galaxy Cluster ◽

X Ray ◽

Deconvolution Technique

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LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations

Astronomy and Astrophysics ◽

10.1051/0004-6361:20079103 ◽

2008 ◽

Vol 482 (2) ◽

pp. 451-472 ◽

Cited By ~ 140

Author(s):

Y.-Y. Zhang ◽

A. Finoguenov ◽

H. Böhringer ◽

J.-P. Kneib ◽

G. P. Smith ◽

...

Keyword(s):

Galaxy Cluster ◽

Scaling Relations ◽

X Ray

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Radio and X-ray Observations of the Restarted Radio Galaxy in the Galaxy Cluster CL 0838+1948

Galaxies ◽

10.3390/galaxies9040108 ◽

2021 ◽

Vol 9 (4) ◽

pp. 108

Author(s):

Simona Giacintucci ◽

Tracy Clarke ◽

Namir E. Kassim ◽

Wendy Peters ◽

Emil Polisensky

Keyword(s):

Radio Source ◽

Survey Data ◽

Radio Galaxy ◽

Galaxy Cluster ◽

Gas Emission ◽

Low Frequencies ◽

Nuclear Activity ◽

X Ray ◽

Hot Gas ◽

The Galaxy

We present VLA Low-band Ionosphere and Transient Experiment (VLITE) 338 MHz observations of the galaxy cluster CL 0838+1948. We combine the VLITE data with Giant Metrewave Radio Telescope 610 MHz observations and survey data. The central galaxy hosts a 250 kpc source whose emission is dominated by two large lobes at low frequencies. At higher frequencies, a pair of smaller lobes (∼30 kpc) is detected within the galaxy optical envelope. The observed morphology is consistent with a restarted radio galaxy. The outer lobes have a spectral index αout=1.6, indicating that they are old, whereas the inner lobes have αinn=0.6, typical for an active source. Spectral modeling confirms that the outer emission is a dying source whose nuclear activity switched off not more than 110 Myr ago. Using archival Chandra X-ray data, we compare the radio and hot gas emission. We find that the active radio source is contained within the innermost and X-ray brightest region, possibly a galactic corona. Alternatively, it could be the remnant of a larger cool core whose outer layers have been heated by the former epoch of activity that has generated the outer lobes.

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