scholarly journals Gravitational Lensing Of Quasar 0957+561 And The Determination Of H0

1996 ◽  
Vol 173 ◽  
pp. 49-50 ◽  
Author(s):  
George Rhee ◽  
Gary Bernstein ◽  
Tony Tyson ◽  
Phil Fischer
Keyword(s):  
Gravitational Lensing ◽  
Galaxy Cluster ◽  
Cluster Center ◽  
Center Location ◽  
Multiple Imaging ◽  
Unique Model ◽  
The Galaxy

The double quasar 0957+561 was the first discovered instance of multiple imaging via gravitational lensing. The galaxy cluster is an important deflector as well as the first ranked galaxy. This has so far precluded construction of a unique model of the lens, reducing the accuracy of the derived H0 value. We have obtained deep images of the system at CFHT. The cluster is sufficiently massive to cause distortions on distant background galaxy images. We have used a mass map derived from lensing distortions to improve the accuracy of the cluster center location and place new limits on H0.

scholarly journals Revising the merger scenario of the galaxy cluster Abell 1644: a new gas poor structure discovered by weak gravitational lensing

2020 ◽  
Vol 495 (2) ◽  
pp. 2007-2021 ◽  
Author(s):  
R Monteiro-Oliveira ◽  
L Doubrawa ◽  
R E G Machado ◽  
G B Lima Neto ◽  
M Castejon ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Elliptical Galaxy ◽  
Galaxy Cluster ◽  
X Ray ◽  
The North ◽  
Density Maps ◽  
Hydrodynamical Simulation ◽  
The Galaxy ◽  
Maximum Separation ◽  
Comprehensive Study

ABSTRACT The galaxy cluster Abell 1644 ($\bar{z}=0.047$) is known for its remarkable spiral-like X-ray emission. It was previously identified as a bimodal system, comprising the subclusters, A1644S and A1644N, each one centred on a giant elliptical galaxy. In this work, we present a comprehensive study of this system, including new weak lensing and dynamical data and analysis plus a tailor-made hydrodynamical simulation. The lensing and galaxy density maps showed a structure in the North that could not be seen on the X-ray images. We, therefore, rename the previously known northern halo as A1644N1 and the new one as A1644N2. Our lensing data suggest that those have fairly similar masses: $M_{200}^{\rm N1}=0.90_{-0.85}^{+0.45} \times 10^{14}$ and $M_{200}^{\rm N2}=0.76_{-0.75}^{+0.37} \times 10^{14}$ M⊙, whereas the southern structure is the main one: $M_{200}^{\rm S}=1.90_{-1.28}^{+0.89}\times 10^{14}$ M⊙. Based on the simulations, fed by the observational data, we propose a scenario where the remarkable X-ray characteristics in the system are the result of a collision between A1644S and A1644N2 that happened ∼1.6 Gyr ago. Currently, those systems should be heading to a new encounter, after reaching their maximum separation.

scholarly journals Galaxies and clusters of galaxies as peak patches of the density field

2019 ◽  
Vol 490 (2) ◽  
pp. 1693-1696 ◽  
Author(s):  
Masataka Fukugita ◽  
Hans Böhringer
Keyword(s):  
Gravitational Lensing ◽  
Mass Density ◽  
Galaxy Cluster ◽  
Mass Range ◽  
Mass Function ◽  
Clusters Of Galaxies ◽  
Density Fraction ◽  
The Galaxy ◽  
Consistent Picture ◽  
Low Mass

ABSTRACT The mass function of galaxies and clusters of galaxies can be derived observationally based on different types of observations. In this study we test if these observations can be combined to a consistent picture which is also in accord with structure formation theory. The galaxy data comprise the optical galaxy luminosity function and the gravitational lensing signature of the galaxies, while the galaxy cluster mass function is derived from the X-ray luminosity distribution of the clusters. We show the results of the comparison in the form of the mass density fraction that is contained in collapsed objects relative to the mean matter density in the Universe. The mass density fraction in groups and clusters of galaxies extrapolated to low masses agrees very well with that of the galaxies: both converge at the low mass limit to a mass fraction of about 28 per cent if the outer radii of the objects are taken to be r200. Most of the matter contained in collapsed objects is found in the mass range $M_{200} \sim 10^{12}\!-\!10^{14}\, h^{-1}_{70} \, \mathrm{M}_\odot$, while a larger amount of the cosmic matter resides outside of r200 of collapsed objects.

Mass Discrepancy in the Galaxy Cluster RBS 864 Derived from X-rays and Gravitational Lensing

2006 ◽  
Vol 20 ◽  
pp. 281-282
Author(s):  
M. Gitti ◽  
W. Kausch ◽  
T. Erben ◽  
S. Schindler
Keyword(s):  
Gravitational Lensing ◽  
Galaxy Cluster ◽  
X Rays ◽  
The Galaxy

scholarly journals The Multiply Imaged Strongly Lensed Supernova Refsdal

2015 ◽  
Vol 11 (A29B) ◽  
pp. 822-824
Author(s):  
Patrick Kelly
Keyword(s):  
Rest Frame ◽  
Hubble Space Telescope ◽  
Galaxy Cluster ◽  
Supernova Explosion ◽  
Gravitational Lens ◽  
Cluster Center ◽  
Arrival Times ◽  
The Galaxy ◽  
Multiple Paths ◽  
Massive Galaxy

AbstractIn 1964, Sjur Refsdal first considered the possibility that the light from a background supernova could traverse multiple paths around a strong gravitational lens towards us. He showed that the arrival times of the supernova's light would depend on the cosmic expansion rate, as well as the distribution of matter in the lens. I discussed the discovery of the first such multiply imaged supernova, which exploded behind the MACS J1149.6+2223 galaxy cluster. We have obtained Hubble Space Telescope grism and ground-based spectra of the four images of the supernova, which form an Einstein Cross configuration around an elliptical cluster member. These spectra as well as rest-frame optical light curves have allowed us to learn about the properties of the peculiar core-collapse supernova explosion, which occurred 4.3 Gyr after the Bang Bang, and contain information about the lenses matter distribution as well as their stellar populations. A delayed image of the supernova is expected close to the galaxy cluster center as early as this Fall, and will serve as an unprecedented probe of the potential of a massive galaxy cluster.

scholarly journals Tightening the constraints on the mass distribution of the Frontier Fields MACSJ0416.1-2403 with VLT/MUSE spectroscopy

2015 ◽  
Vol 11 (A29B) ◽  
pp. 781-782
Author(s):  
Benjamin Clément ◽  
Johan Richard ◽  
Guillaume Mahler ◽  
Vera Patrício ◽  
David Lagattuta ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Gravitational Lensing ◽  
Previous Analysis ◽  
Galaxy Cluster ◽  
Field Of View ◽  
Cluster Core ◽  
Large Field ◽  
Mass Model ◽  
Optical Wavelength ◽  
The Galaxy

AbstractWe have combined the performances of the VLT/MUSE spectrograph together with the power of gravitational lensing by Frontier Fields galaxy clusters to offer a unique magnified view of the distant universe. The large field of view over a wide optical wavelength domain enables redshift measurements of numerous lensed galaxies in the cluster core. Spectroscopically-confirmed multiple-imaged systems are further used as strong constraints to improve the cluster mass model. Here, we focus on the galaxy cluster MACSJ0416.1-2403 and compare the revised magnification map with results from previous analysis.

scholarly journals Diffuse galaxy cluster emission at 168 MHz within the Murchison Widefield Array Epoch of Reionization 0-h field

2021 ◽  
Vol 38 ◽  
Author(s):  
S. W. Duchesne ◽  
M. Johnston-Hollitt ◽  
A. R. Offringa ◽  
G. W. Pratt ◽  
Q. Zheng ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Galaxy Cluster ◽  
Scaling Relations ◽  
Cluster Emission ◽  
X Ray ◽  
Diffuse Sources ◽  
Radio Halo ◽  
The Galaxy ◽  
Murchison Widefield Array

Abstract We detect and characterise extended, diffuse radio emission from galaxy clusters at 168 MHz within the Epoch of Reionization 0-h field: a $45^{\circ} \times 45^{\circ}$ region of the southern sky centred on R. A. ${}= 0^{\circ}$ , decl. ${}=-27^{\circ}$ . We detect 29 sources of interest; a newly detected halo in Abell 0141; a newly detected relic in Abell 2751; 4 new halo candidates and a further 4 new relic candidates; and a new phoenix candidate in Abell 2556. Additionally, we find nine clusters with unclassifiable, diffuse steep-spectrum emission as well as a candidate double relic system associated with RXC J2351.0-1934. We present measured source properties such as their integrated flux densities, spectral indices ( $\alpha$ , where $S_\nu \propto \nu^\alpha$ ), and sizes where possible. We find several of the diffuse sources to have ultra-steep spectra including the halo in Abell 0141, if confirmed, showing $\alpha \leq -2.1 \pm 0.1$ with the present data making it one of the steepest-spectrum haloes known. Finally, we compare our sample of haloes with previously detected haloes and revisit established scaling relations of the radio halo power ( $P_{1.4}$ ) with the cluster X-ray luminosity ( $L_{\textrm{X}}$ ) and mass ( $M_{500}$ ). We find that the newly detected haloes and candidate haloes are consistent with the $P_{1.4}$ – $L_{\textrm{X}}$ and $P_{1.4}$ – $M_{500}$ relations and see an increase in scatter in the previously found relations with increasing sample size likely caused by inhomogeneous determination of $P_{1.4}$ across the full halo sample. We show that the MWA is capable of detecting haloes and relics within most of the galaxy clusters within the Planck catalogue of Sunyaev–Zel’dovich sources depending on exact halo or relic properties.

scholarly journals ChandraObservations of the Galaxy Cluster A478: The Interaction of Hot Gas and Radio Plasma in the Core, and an Improved Determination of the Comptony‐Parameter

2003 ◽  
Vol 587 (2) ◽  
pp. 619-624 ◽  
Author(s):  
M. Sun ◽  
C. Jones ◽  
S. S. Murray ◽  
S. W. Allen ◽  
A. C. Fabian ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Hot Gas ◽  
The Core ◽  
The Galaxy

scholarly journals Probing Saraswati’s heart: evaluating the dynamical state of the massive galaxy cluster A2631 through a comprehensive weak-lensing and dynamical analysis

2020 ◽  
Vol 501 (1) ◽  
pp. 756-768
Author(s):  
R Monteiro-Oliveira ◽  
A C Soja ◽  
A L B Ribeiro ◽  
J Bagchi ◽  
S Sankhyayan ◽  
...  
Keyword(s):  
Galaxy Cluster ◽  
Dynamical Analysis ◽  
Weak Lensing ◽  
Data Sets ◽  
Dynamical State ◽  
Massive Structure ◽  
The Galaxy ◽  
Dynamics Of Galaxies ◽  
Massive Galaxy

ABSTRACT In this work, we investigate the dynamical state of the galaxy cluster Abell 2631, a massive structure located at the core of the Saraswati supercluster. To do this, we first solve a tension found in the literature regarding the weak-lensing mass determination of the cluster. We do this through a comprehensive weak-lensing analysis, exploring the power of the combination of shear and magnification data sets. We find $M_{200}^{\rm wl} = 8.7_{-2.9}^{+2.5} \times 10^{14}$ M⊙. We also determined the mass based on the dynamics of spectroscopic members, corresponding to $M_{200}^{\rm dy} = 12.2\pm 3.0 \times 10^{14}$ M⊙, consistent within a 68 per cent CL with the weak-lensing estimate. The scenarios provided by the mass distribution and dynamics of galaxies are reconciled with those provided by X-ray observations in a scenario where A2631 is observed at a late stage of merging.

Sign in / Sign up

Export Citation Format

Share Document