- ID:
- ivo://CDS.VizieR/J/MNRAS/425/1215
- Title:
- Multiwavelength survey of AGNs
- Short Name:
- J/MNRAS/425/1215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to study the effect of environment on the presence and fuelling of active galactic nuclei (AGNs) in massive galaxy clusters. We explore the use of different AGN detection techniques with the goal of selecting AGN across a broad range of luminosities, AGN/host galaxy flux ratios and obscuration levels. From a sample of 12 galaxy clusters at redshifts 0.5<z<0.9, we identify AGN candidates using optical variability from multi-epoch Hubble Space Telescope imaging, X-ray point sources in Chandra images and mid-infrared (IR) spectral energy distribution power-law fits through the Spitzer Infrared Array Camera channels. We find 178 optical variables, 74 X-ray point sources and 64 IR power-law sources, resulting in an average of ~25 AGN per cluster.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/663
- Title:
- MUSE and HFFs Photometry of A2744
- Short Name:
- J/MNRAS/473/663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of Multi Unit Spectroscopic Explorer (MUSE) observations obtained on the massive Frontier Fields (FFs) cluster A2744. This new data set covers the entire multiply imaged region around the cluster core. The combined catalogue consists of 514 spectroscopic redshifts (with 414 new identifications). We use this redshift information to perform a strong-lensing analysis revising multiple images previously found in the deep FF images, and add three new MUSE-detected multiply imaged systems with no obvious Hubble Space Telescope counterpart. The combined strong-lensing constraints include a total of 60 systems producing 188 images altogether, out of which 29 systems and 83 images are spectroscopically confirmed, making A2744 one of the most well-constrained clusters to date. Thanks to the large amount of spectroscopic redshifts, we model the influence of substructures at larger radii, using a parametrization including two cluster-scale components in the cluster core and several group scale in the outskirts. The resulting model accurately reproduces all the spectroscopic multiple systems, reaching an rms of 0.67-arcsec in the image plane. The large number of MUSE spectroscopic redshifts gives us a robust model, which we estimate reduces the systematic uncertainty on the 2D mass distribution by up to ~2.5 times the statistical uncertainty in the cluster core. In addition, from a combination of the parametrization and the set of constraints, we estimate the relative systematic uncertainty to be up to 9 per cent at 200kpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/772/131
- Title:
- Musket Ball Cluster redshift catalog
- Short Name:
- J/ApJ/772/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Merging galaxy clusters have become one of the most important probes of dark matter, providing evidence for dark matter over modified gravity and even constraints on the dark matter self-interaction cross-section. To properly constrain the dark matter cross-section it is necessary to understand the dynamics of the merger, as the inferred cross-section is a function of both the velocity of the collision and the observed time since collision. While the best understanding of merging system dynamics comes from N-body simulations, these are computationally intensive and often explore only a limited volume of the merger phase space allowed by observed parameter uncertainty. Simple analytic models exist but the assumptions of these methods invalidate their results near the collision time, plus error propagation of the highly correlated merger parameters is unfeasible. To address these weaknesses I develop a Monte Carlo method to discern the properties of dissociative mergers and propagate the uncertainty of the measured cluster parameters in an accurate and Bayesian manner. I introduce this method, verify it against an existing hydrodynamic N-body simulation, and apply it to two known dissociative mergers: 1ES 0657-558 (Bullet Cluster) and DLSCL J0916.2+2951 (Musket Ball Cluster).
- ID:
- ivo://CDS.VizieR/J/A+A/571/L4
- Title:
- MWC 349A Halpha lines with 14<n<24 spectra
- Short Name:
- J/A+A/571/L4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The UC-HII region of MWC 349A is the prototype of an ionized wind driven by a massive star surrounded by a disk. Recent high angular resolution observations of the millimeter recombination lines have shown that the disk rotates with a Keplerian law in its outer parts. However, the kinematics of innermost regions in the UC-HII region of MWC 349A is still unknown, in particular the radius where the wind is launched from the disk. We performed hydrogen recombination line observations with the Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory to study the kinematics of its innermost regions by studying their spectral features. In addition to the two laser peaks, we report the first detection of two new components that are blueshifted with respect to the laser peaks for all the recombination lines with principal quantum number n<22. These new spectral features originate from the region where the wind is ejected from the disk. We used our 3D non-LTE radiative transfer model for recombination lines (MORELI) to show that these features are consistent with the wind being ejected at a radius of about 24 AU from the star, which supports magnetohydrodynamic wind models.
- ID:
- ivo://CDS.VizieR/J/ApJS/115/1
- Title:
- MX northern Abell cluster redshift survey
- Short Name:
- J/ApJS/115/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results from the COBE satellite show the existence of structure on scales ~ 10% or more of the horizon scale of the universe. Rich clusters of galaxies from the Abell/Abell, Corwin, & Olowin catalogs (Cat. <VII/110>) show evidence of structure on scales of 100h^-1^Mpc and hold the promise of confirming structure on the scale of the COBE results. An impediment to that promise has been that redshift information has been unavailable for a large percentage of these clusters, so knowledge of their three-dimensional distribution has had large uncertainties. We have been working to greatly expand the sample of Abell clusters with reliable redshifts. Our approach in this effort, through the MX Northern Abell Cluster Redshift Survey, has been to measure redshifts of at least 25 galaxies in each of 95 R>=1 Abell cluster fields with m_10_<=16.8 and zero or one previously measured redshift. Of these 95 observed Abell clusters, 88 new cluster redshifts were obtained with an average of nine cluster member galaxy redshifts per field. Two clusters were found to be chance projections of galaxies along the line of sight, while five cluster observations did not provide enough galaxy redshifts to make a positive identification. This work has resulted in a deeper, 98% complete, and more reliable sample of three-dimensional positions of rich Abell clusters in the northern hemisphere. The primary intent of this survey has been to produce a larger and more complete sample of rich Abell clusters that can be used as tracers for large-scale structure. Through analyses with tools such as the two-point correlation function, power spectrum, and velocity dispersions, this sample can be used to constrain theoretical models better for the formation of structure we see in the universe today.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1918
- Title:
- MX northern Abell cluster redshift survey. II.
- Short Name:
- J/AJ/124/1918
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The MX Northern Abell Cluster Survey II is the final stage of a program designed to observe rich Abell clusters with m10<=17.0. We present 1542 new galaxy redshifts within 117 R>=1 Abell cluster fields that have 16.9<=m10<=17.0, 0h<=RA<=24h, -17{deg}<=DE<=90{deg}, and |b|>=30{deg}. Of the 117 clusters observed for the MX Survey II, 105 new cluster redshifts were obtained with an average of eight cluster member galaxy redshifts.
- ID:
- ivo://CDS.VizieR/J/A+AS/94/327
- Title:
- Nearby clusters of galaxies. I.
- Short Name:
- J/A+AS/94/327
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of the properties of nearby clusters of galaxies has been undertaken. This paper describes the data, derived from automated scans of photographic plates. Different methods for the evaluation of cluster center, ellipticity and orientation are compared and errors are estimated by Monte Carlo simulations. We present the results of the analysis of 1256 galaxies brighter than m_3_+3 in eight Abell clusters. We find that different methods give consistent estimates of ellipticity and orientation, provided the radial dependence of these quantities is taken into account. We also find that central densities are consistent with isothermal fits if the center is selected as the baricenter of the cluster. For each galaxy, rectangular coordinates, magnitude, size, ellipticity and orientation are given. For each cluster we provide identification maps and contour maps of galaxy surface density.
- ID:
- ivo://CDS.VizieR/J/A+AS/125/459
- Title:
- Nearby clusters of galaxies properties. III.
- Short Name:
- J/A+AS/125/459
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is the third of a series (Trevese et al. 1992, Paper I, Cat. <J/A+AS/94/327>, Flin et al. 1995, Cat. <J/A+AS/110/313>, Paper II, presenting F band photometry, from digitized 48-inch Palomar plates, of the galaxies brighter than m_3_+3 in a clusters. For each galaxy, absolute coordinates, magnitude, size, ellipticity and orientation are given. For each cluster we provide finding charts and contour maps of the galaxy surface density. In the present paper we analyze 15 new clusters and provide the absolute alpha and delta coordinates of the galaxies of 8 Abell clusters, studied in pap. I, which were published with relative coordinates only. In the electronic version, the tables of the 8 clusters of pap. I are written in the same format of papers II and III.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/4990
- Title:
- Nearby galaxy clusters X-ray point sources
- Short Name:
- J/MNRAS/471/4990
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we studied 10 nearby (z<=0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the intra-cluster medium. We examined the spectral properties of a total of 391 X-ray point sources within each cluster's potential well. log N versus log S was studied in the energy range 2-10 keV to measure X-ray overdensities. Optical overdensities were also calculated to solve suppression/triggering phenomena for nearby galaxy clusters. X-ray and optical flux/luminosity properties (X/O, L_X_/L_B_ and L_X_/L_K_) were investigated for optically identified member galaxies. The X-ray luminosities of our point sources were found to be faint [40.08<=log(L_X_)<=42.39erg/s]. The luminosity range of point sources reveals possible contributions to X-ray emission from low-luminosity active galactic nuclei, X-ray binaries and star formation. We estimated ~2 times higher X-ray overdensities from galaxies within galaxy clusters compared to fields. Our results demonstrate that optical overdensities are much higher than X-ray overdensities at a cluster's centre, whereas X-ray overdensities increase through the outskirts of clusters. We conclude that high pressure from a cluster's centre affects the balance of galaxies and they lose a significant amount of their fuel. As a result, the clustering process quenches the X-ray emission of the member galaxies. We also find evidence that the existence of X-ray bright sources within a cluster environment can be explained by two main phenomena: contributions from off-nuclear sources and/or active galactic nucleus (AGN) triggering caused by galaxy interactions rather than AGN fuelling.
680. Nearby galaxy flows
- ID:
- ivo://CDS.VizieR/J/ApJS/80/479
- Title:
- Nearby galaxy flows
- Short Name:
- J/ApJS/80/479
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supporting material for an article in the main journal is presented. One table gives measured galaxy distances used to construct a map of observed peculiar velocities, and another table gives a grid of the distribution of light used to construct a map of expected peculiar velocities. A preferred model was developed which gave a best fit between these maps, and this model has been used to generate output kinematic distances which are recorded here for groups and individual galaxies with V_0_<3000km/s.
