scholarly journals A Spectroscopic Redshift for the Cl 0024+16 Multiple Arc System: Implications for the Central Mass Distribution

2000 ◽  
Vol 534 (1) ◽  
pp. L15-L18 ◽  
Author(s):  
Tom Broadhurst ◽  
Xiaosheng Huang ◽  
Brenda Frye ◽  
Richard Ellis
Keyword(s):  
Mass Distribution ◽  
Central Mass

scholarly journals The Mass Distribution in the Central Few Parsecs of the Galaxy

1989 ◽  
Vol 136 ◽  
pp. 493-499
Author(s):  
John H. Lacy
Keyword(s):  
Mass Distribution ◽  
Gas Dynamics ◽  
Good Evidence ◽  
Ionized Gas ◽  
Massive Black Hole ◽  
Central Mass ◽  
Magnetic Forces ◽  
Gravitational Forces ◽  
The Galaxy

The determination of the mass distribution in the central few parsecs of the Galaxy, primarily from the ionized gas dynamics, is discussed. The gas motions are described and interpreted assuming that the orbits are determined by gravitational forces. It is shown that there is good evidence for a central mass of ~ 2 × 106 M⊙. The primary uncertainty in this conclusion results from the possibility of significant magnetic forces. In the absence of corroborating evidence, the case for a massive black hole cannot be considered proven.

scholarly journals Luminosity Distribution in CD Clusters

1994 ◽  
Vol 161 ◽  
pp. 629-631
Author(s):  
F.W. Baier
Keyword(s):  
Galaxy Clusters ◽  
Mass Distribution ◽  
Mass Concentration ◽  
Central Mass ◽  
Cooling Flows ◽  
Galaxy Distribution ◽  
Cd Galaxies ◽  
Cluster Properties ◽  
General Cluster

The ratio of contributions from cannibalism and from cooling flows to the final cD galaxies in diverse clusters seems to be different. It should be determined by some general cluster properties as for instance the central mass concentration. Assuming that mass distribution is tantamount to luminosity distribution we have analyzed the question of possible luminosity segregation in the radial galaxy distribution of galaxy clusters (Baier & Schmidt 1992; Baier & MacGillivray 1994).

scholarly journals The Mass Distribution in the Galactic Center

1989 ◽  
Vol 136 ◽  
pp. 501-501
Author(s):  
M. T. McGinn ◽  
K. Sellgren ◽  
E. E. Becklin ◽  
D. N. B. Hall
Keyword(s):  
Mass Distribution ◽  
Galactic Center ◽  
Major Constituent ◽  
Galactic Rotation ◽  
Core Radius ◽  
Central Mass ◽  
Stellar Cluster ◽  
The Galaxy ◽  
Stellar Velocity ◽  
Best Fitting

We present the results of a project to map the profile of the 2.3 μm CO V = 2–0 band-head in the integrated starlight in the central 10 pc of the Galaxy. This is the first detailed determination of the kinematics of the faint stars that are the major constituent of the mass of the stellar cluster. The stars exhibit systematic rotation in the same sense as Galactic rotation, with VLSR increasing with Galactocentric radius. The stellar velocity dispersion generally dominates the rotation and shows clear evidence for a radial gradient, in the sense of σ decreasing with Galactocentric radius. The data are consistent with the dynamical center of the Galaxy being located at IRS 16 (to an accuracy of ± 10″). The mass distribution has been derived via the theory of stellar hydrodynamics and is shown in Fig. 1. For an assumed core radius of 10″ (~0.4 pc), the best fitting model is a combination of a central mass of 2.5 × 106 M⊙ and a stellar cluster with a density dependence of r-2.1 (Fig. 1). If the core radius is small (~1″) then the mass distribution could be just due to a stellar cluster; a central condensed mass is not required to model the data in that case.

scholarly journals The Central Mass Distribution in Dwarf and Low Surface Brightness Galaxies

2003 ◽  
Vol 583 (2) ◽  
pp. 732-751 ◽  
Author(s):  
R. A. Swaters ◽  
B. F. Madore ◽  
Frank C. van den Bosch ◽  
M. Balcells
Keyword(s):  
Mass Distribution ◽  
Surface Brightness ◽  
Central Mass ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

scholarly journals Automatic Selection of Multiple Images in the Frontier Field Clusters

2015 ◽  
Vol 11 (A29B) ◽  
pp. 779-780
Author(s):  
Guillaume Mahler ◽  
Johan Richard ◽  
Benjamin Clément ◽  
David Lagattuta ◽  
Vera Patricio
Keyword(s):  
Galaxy Clusters ◽  
Mass Distribution ◽  
Gravitational Lensing ◽  
Matter Content ◽  
Central Mass ◽  
Multiple Images ◽  
Multiple Image ◽  
Inner Region ◽  
Selection Of

AbstractProbing the central mass distribution of massive galaxy clusters is an important step towards mapping the overall distribution of their dark matter content. Thanks to gravitational lensing and the appearance of multiple images, we can constrain the inner region of galaxy clusters with a high precision. The Frontier Fields (FF) provide us with the deepest HST data ever in such clusters. Currently, most multiple-image systems are found by eye, yet in the FF, we expect hundreds to exist. Thus, in order to deal with such huge amounts of data, we need to develop an automated detection method. I present a new tool to perform this task, MISE (Multiple Image SEarcher), a program which identifies multiple images by combining their specific properties. MISE allows us to confirm or reject multiple images identified visually, but also detect new multiple-image candidates in MACS0416 and A2744, giving us additional constraints on the mass distribution in these clusters. A spectroscopic follow-up of these candidates is currently underway with MUSE.

scholarly journals What we learn from the Frontier Fields cluster MACS J0416.1-2403

2015 ◽  
Vol 11 (A29B) ◽  
pp. 787-790
Author(s):  
S. H. Suyu ◽  
C. Grillo ◽  
P. Rosati
Keyword(s):  
Mass Distribution ◽  
Hubble Space Telescope ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Essential Elements ◽  
Central Mass ◽  
Great Opportunity ◽  
Space Telescope ◽  
James Webb Space Telescope ◽  
High Redshift Universe

AbstractThe Frontier Fields cluster MACS J0416.1-2403 with its extensive imaging and spectroscopic data sets provides a great opportunity to study the mass distribution of the galaxy cluster and members, the high-redshift Universe and cosmology. By taking advantage of the observations in the 16 Hubble Space Telescope imaging bands of the Cluster Lensing And Supernova survey with Hubble (CLASH) survey and our large spectroscopic follow-up program with the VIsible Multi-Object Spectrograph (VIMOS) on the Very Large Telescope (VLT), we have been able to identify and obtain the spectroscopic redshifts of 10 important strong lensing systems in this cluster. Furthermore, we have selected and modeled the mass distribution of ~200 candidate cluster members residing in the inner regions of the cluster. We present the results on the model-predicted central mass profile and subhalo population, which are detailed in Grillo et al. (2015). Work is underway to quantify the effects of line-of-sight structures. These are essential elements to make progress in our understanding of the dark matter distribution in massive galaxy clusters and of the distant Universe within the current Frontier Fields initiative and before the advent of the James Webb Space Telescope.

scholarly journals The effect of models of the interstellar media on the central mass distribution of galaxies

2014 ◽  
Vol 440 (3) ◽  
pp. 2843-2859 ◽  
Author(s):  
C. R. Christensen ◽  
F. Governato ◽  
T. Quinn ◽  
A. M. Brooks ◽  
S. Shen ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Central Mass ◽  
Interstellar Media

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Sign in / Sign up

Export Citation Format

Share Document