scholarly journals Abell 3627: A Nearby, X-Ray Bright, and Massive Galaxy Cluster

1996 ◽  
Vol 467 ◽  
pp. 168 ◽  
Author(s):  
H. Boehringer ◽  
D. M. Neumann ◽  
S. Schindler ◽  
R. C. Kraan-Korteweg
Keyword(s):  
Galaxy Cluster ◽  
X Ray ◽  
Massive Galaxy

scholarly journals The massive galaxy cluster XMMU J1230.3+1339 at z ∼ 1: colour-magnitude relation, Butcher-Oemler effect, X-ray and weak lensing mass estimates★

2011 ◽  
Vol 411 (4) ◽  
pp. 2667-2694 ◽  
Author(s):  
M. Lerchster ◽  
S. Seitz ◽  
F. Brimioulle ◽  
R. Fassbender ◽  
M. Rovilos ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray ◽  
Massive Galaxy

scholarly journals Interaction of Cygnus A with its environment

2014 ◽  
Vol 10 (S313) ◽  
pp. 236-241
Author(s):  
Paul E. J. Nulsen ◽  
Andrew J. Young ◽  
Ralph P. Kraft ◽  
Brian R. McNamara ◽  
Michael W. Wise
Keyword(s):  
Energy Flow ◽  
Radio Galaxy ◽  
Galaxy Cluster ◽  
Solar Mass ◽  
X Ray ◽  
Radio Jets ◽  
Cygnus A ◽  
Radio Lobe ◽  
Massive Galaxy ◽  
Powerful Radio Galaxy

AbstractCygnus A, the nearest truly powerful radio galaxy, resides at the centre of a massive galaxy cluster. Chandra X-ray observations reveal its cocoon shocks, radio lobe cavities and an X-ray jet, which are discussed here. It is argued that X-ray emission from the outer regions of the cocoon shocks is nonthermal. The X-ray jets are best interpreted as synchrotron emission, suggesting that they, rather than the radio jets, are the path of energy flow from the nucleus to the hotspots. In that case, a model shows that the jet flow is non-relativistic and carries in excess of one solar mass per year.

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

1999 ◽  
Vol 118 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Piero Rosati ◽  
S. A. Stanford ◽  
Peter R. Eisenhardt ◽  
Richard Elston ◽  
Hyron Spinrad ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
X Ray

scholarly journals The role of AGN activity in the building up of the BCG at z ∼ 1.6

2019 ◽  
Vol 15 (S356) ◽  
pp. 280-284
Author(s):  
Angela Bongiorno ◽  
Andrea Travascio
Keyword(s):  
Galaxy Cluster ◽  
Cluster Galaxy ◽  
X Ray ◽  
Groups Of Galaxies ◽  
Star Forming ◽  
The Core ◽  
The Galaxy ◽  
Multi Wavelength

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.

scholarly journals Reconciling galaxy cluster shapes, measured by theorists versus observers

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.

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

2016 ◽  
Vol 466 (3) ◽  
pp. 3663-3673 ◽  
Author(s):  
Melanie Simet ◽  
Nicholas Battaglia ◽  
Rachel Mandelbaum ◽  
Uroš Seljak
Keyword(s):  
Galaxy Cluster ◽  
Weak Lensing ◽  
X Ray ◽  
Mass Bias

scholarly journals IDCS J1426.5+3508: THE MOST MASSIVE GALAXY CLUSTER ATz> 1.5

2016 ◽  
Vol 817 (2) ◽  
pp. 122 ◽  
Author(s):  
Mark Brodwin ◽  
Michael McDonald ◽  
Anthony H. Gonzalez ◽  
S. A. Stanford ◽  
Peter R. Eisenhardt ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Massive Galaxy

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

2018 ◽  
Vol 611 ◽  
pp. A50 ◽  
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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