scholarly journals X-ray bright active galactic nuclei in massive galaxy clusters – I. Number counts and spatial distribution

2012 ◽  
Vol 428 (4) ◽  
pp. 3509-3525 ◽  
Author(s):  
S. Ehlert ◽  
S. W. Allen ◽  
W. N. Brandt ◽  
Y. Q. Xue ◽  
B. Luo ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Galactic Nuclei ◽  
X Ray ◽  
Number Counts ◽  
Massive Galaxy

scholarly journals X-ray bright active galactic nuclei in massive galaxy clusters – II. The fraction of galaxies hosting active nuclei

2013 ◽  
Vol 437 (2) ◽  
pp. 1942-1949 ◽  
Author(s):  
S. Ehlert ◽  
A. von der Linden ◽  
S. W. Allen ◽  
W. N. Brandt ◽  
Y. Q. Xue ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Galactic Nuclei ◽  
X Ray ◽  
Massive Galaxy

The Fall of Active Galactic Nuclei and the Rise of Star-forming Galaxies: A Close Look at the Chandra Deep Field X-Ray Number Counts

2004 ◽  
Vol 128 (5) ◽  
pp. 2048-2065 ◽  
Author(s):  
F. E. Bauer ◽  
D. M. Alexander ◽  
W. N. Brandt ◽  
D. P. Schneider ◽  
E. Treister ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
X Ray ◽  
Star Forming ◽  
Number Counts

scholarly journals The impact of disturbed galaxy clusters on the kinematics of active galactic nuclei

2020 ◽  
Vol 499 (3) ◽  
pp. 3792-3805
Author(s):  
Lawrence E Bilton ◽  
Kevin A Pimbblet ◽  
Yjan A Gordon
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Velocity Dispersion ◽  
Signal To Noise Ratio ◽  
Galactic Nuclei ◽  
Sloan Digital Sky Survey ◽  
X Ray ◽  
Cluster Galaxies ◽  
Sky Survey ◽  
The Impact

ABSTRACT We produce a kinematic analysis of AGN-hosting cluster galaxies from a sample of 33 galaxy clusters selected using the X-ray Clusters Database (BAX) and populated with galaxies from the Sloan Digital Sky Survey Data Release 8. The 33 galaxy clusters are delimited by their relative intensity of member galaxy substructuring as a proxy to core merging to derive two smaller sub-samples of 8 dynamically active (merging) and 25 dynamically relaxed (non-merging) states. The AGN were selected for each cluster sub-sample by employing the WHAN diagram to the strict criteria of log10([N ii]/Hα) ≥ −0.32 and EWHα ≥ 6 Å, providing pools of 70 mergings and 225 non-merging AGN sub-populations. By co-adding the clusters to their respective dynamical states to improve the signal-to-noise ratio of our AGN sub-populations we find that merging galaxy clusters on average host kinematically active AGN between 0–1.5r200 as r200 → 0, where their velocity dispersion profile (VDP) presents a significant deviation from the non-AGN sub-population VDP by ≳3σ. This result is indicative that the AGN-hosting cluster galaxies have recently coalesced on to a common potential. Further analysis of the composite distributions illustrates non-merging AGN-hosting sub-populations have, on average, already been accreted and predominantly lie within backsplash regions of the projected phase-space. This suggests merging cluster dynamical states hold relatively younger AGN sub-populations kinematically compared with those found in non-merging cluster dynamical states.

X-ray Luminosity function of Active Galactic Nuclei in Galaxy clusters

2009 ◽  
Author(s):  
Yuxuan Yang ◽  
Joseph J. Mohr ◽  
Tim O’Hara ◽  
Sebastian Heinz ◽  
Eric Wilcots
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Luminosity Function ◽  
Galactic Nuclei ◽  
X Ray

scholarly journals THENuSTAREXTRAGALACTIC SURVEYS: THE NUMBER COUNTS OF ACTIVE GALACTIC NUCLEI AND THE RESOLVED FRACTION OF THE COSMIC X-RAY BACKGROUND

2016 ◽  
Vol 831 (2) ◽  
pp. 185 ◽  
Author(s):  
F. A. Harrison ◽  
J. Aird ◽  
F. Civano ◽  
G. Lansbury ◽  
J. R. Mullaney ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
X Ray ◽  
X Ray Background ◽  
Number Counts

scholarly journals The XXL Survey

2018 ◽  
Vol 620 ◽  
pp. A6 ◽  
Author(s):  
O. Melnyk ◽  
A. Elyiv ◽  
V. Smolčić ◽  
M. Plionis ◽  
E. Koulouridis ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Small Scale ◽  
Radio Sources ◽  
Large Area ◽  
Distance Method ◽  
X Ray ◽  
Structure Information

Context. This work is part of a series of studies focusing on the environment and the properties of the X-ray selected active galactic nuclei (AGN) population from the XXL survey. The present survey, given its large area, continuity, extensive multiwavelength coverage, and large-scale structure information, is ideal for this kind of study. Here, we focus on the XXL-South (XXL-S) field. Aims. Our main aim is to study the environment of the various types of X-ray selected AGN and investigate its possible role in AGN triggering and evolution. Methods. We studied the large-scale (>1 Mpc) environment up to redshift z = 1 using the nearest neighbour distance method to compare various pairs of AGN types. We also investigated the small-scale environment (<0.4 Mpc) by calculating the local overdensities of optical galaxies. In addition, we built a catalogue of AGN concentrations with two or more members using the hierarchical clustering method and we correlated them with the X-ray galaxy clusters detected in the XXL survey. Results. It is found that radio detected X-ray sources are more obscured than non-radio ones, though not all radio sources are obscured AGN. We did not find any significant differences in the large-scale clustering between luminous and faint X-ray AGN, or between obscured and unobscured ones, or between radio and non-radio sources. At local scales (<0.4 Mpc), AGN typically reside in overdense regions, compared to non-AGN; however, no differences were found between the various types of AGN. A majority of AGN concentrations with two or more members are found in the neighbourhood of X-ray galaxy clusters within <25–45 Mpc. Our results suggest that X-ray AGN are typically located in supercluster filaments, but they are also found in over- and underdense regions.

scholarly journals High density of active galactic nuclei in the outskirts of distant galaxy clusters

2019 ◽  
Vol 623 ◽  
pp. L10 ◽  
Author(s):  
E. Koulouridis ◽  
I. Bartalucci
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Statistical Significance ◽  
Galactic Nuclei ◽  
Average Density ◽  
Point Sources ◽  
Source Surface ◽  
Essential Property ◽  
X Ray ◽  
Massive Clusters

We present a study of the distribution of X-ray detected active galactic nuclei (AGN) in the five most massive, M500SZ > 1014 M⊙, and distant, z ∼ 1, galaxy clusters in the Planck and South Pole Telescope (SPT) surveys. The spatial and thermodynamic individual properties of each cluster have been defined with unprecedented accuracy at this redshift using deep X-ray observations. This is an essential property of our sample in order to precisely determine the R500Yx radius of the clusters. For our purposes, we computed the X-ray point-like source surface density in 0.5 R500Yx wide annuli up to a clustercentric distance of 4 R500Yx, statistically subtracting the background and accounting for the respective average density of optical galaxies. We found a significant excess of X-ray point sources between 2 and 2.5 R500Yx at the 99.9% confidence level. The results clearly display for the first time strong observational evidence of AGN triggering in the outskirts of high-redshift massive clusters with such a high statistical significance. We argue that the particular conditions at this distance from the cluster centre increase the galaxy merging rate, which is probably the dominant mechanism of AGN triggering in the outskirts of massive clusters.

scholarly journals LIFTING THE VEIL ON OBSCURED ACCRETION: ACTIVE GALACTIC NUCLEI NUMBER COUNTS AND SURVEY STRATEGIES FOR IMAGING HARD X-RAY MISSIONS

2011 ◽  
Vol 736 (1) ◽  
pp. 56 ◽  
Author(s):  
D. R. Ballantyne ◽  
A. R. Draper ◽  
K. K. Madsen ◽  
J. R. Rigby ◽  
E. Treister
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
X Ray ◽  
The Veil ◽  
Number Counts ◽  
Nuclei Number
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