Induced energy polarization of the vacuum and the rotational curve for the Galaxy

2013 ◽  
Vol 91 (2) ◽  
pp. 126-133 ◽  
Author(s):  
A. Raymond Penner
Keyword(s):  
Mass Distribution ◽  
Rotational Velocity ◽  
Theoretical Curve ◽  
Orbital Velocity ◽  
The Galaxy ◽  
Rotational Curve ◽  
Baryonic Mass ◽  
Good Agreement

The theory of an induced energy polarized vacuum, as previously presented by the author (Penner. Can. J. Phys. 90, 315 (2012)), is used to generate a theoretical rotational curve for the Galaxy. The theoretical curve generated is found to be in good agreement with Sofue's (Publ. Astron. Soc. Jpn. 64, (In press) (2012)) compilation of observations. For the baryonic mass distribution and baryonic Tully–Fisher relationship that is used, the theoretical orbital velocity at the Sun's location is found to be (235 ± 15) km s−1. The galactic rotational velocity is then found to slowly fall from this value as it asymptotically approaches the value of (192 ± 15) km s−1.

scholarly journals PROBING THE CLUSTER MASS DISTRIBUTION USING SUBARU WEAK LENSING DATA

2007 ◽  
Vol 22 (25n28) ◽  
pp. 2099-2106 ◽  
Author(s):  
KEIICHI UMETSU ◽  
MASAHIRO TAKADA ◽  
TOM BROADHURST
Keyword(s):  
Mass Distribution ◽  
Galaxy Cluster ◽  
Entropy Method ◽  
Weak Lensing ◽  
Wide Field ◽  
Imaging Data ◽  
The Galaxy ◽  
Dimensional Reconstruction ◽  
Mass Profile ◽  
Good Agreement

We present results from a weak lensing analysis of the galaxy cluster A1689 (z = 0.183) based on deep wide-field imaging data taken with Suprime-Cam on Subaru telescope. A maximum entropy method has been used to reconstruct directly the projected mass distribution of A1689 from combined lensing distortion and magnification measurements of red background galaxies. The resulting mass distribution is clearly concentrated around the cD galaxy, and mass and light in the cluster are similarly distributed in terms of shape and orientation. The azimuthally-averaged mass profile from the two-dimensional reconstruction is in good agreement with the earlier results from the Subaru one-dimensional analysis of the weak lensing data, supporting the assumption of quasi-circular symmetry in the projected mass distribution of the cluster.

scholarly journals Planetary nebulae in the inner Milky Way

2009 ◽  
Vol 5 (S265) ◽  
pp. 354-355
Author(s):  
Oscar Cavichia ◽  
Roberto D. D. Costa ◽  
Walter J. Maciel
Keyword(s):  
Statistical Analysis ◽  
Milky Way ◽  
Planetary Nebulae ◽  
Galactic Bulge ◽  
Intermediate Mass ◽  
Disk Interface ◽  
The Galaxy ◽  
Outer Border ◽  
Good Agreement

AbstractNew abundances of planetary nebulae located towards the bulge of the Galaxy are derived based on observations made at LNA (Brazil). We present accurate abundances of the elements He, N, S, O, Ar, and Ne for 56 PNe located towards the galactic bulge. The data shows a good agreement with other results in the literature, in the sense that the distribution of the abundances is similar to those works. From the statistical analysis performed, we can suggest a bulge-disk interface at 2.2 kpc for the intermediate mass population, marking therefore the outer border of the bulge and inner border of the disk.

scholarly journals The effect of the Magellanic Clouds on the mass distribution in the galaxy

1991 ◽  
Vol 148 ◽  
pp. 487-488
Author(s):  
G. X. Song
Keyword(s):  
Mass Distribution ◽  
Milky Way ◽  
Galactic Disk ◽  
Initial Position ◽  
Tidal Effect ◽  
Magellanic Clouds ◽  
The Galaxy

The disk of the Milky Way suffered from the tidal effect as the Magellanic Clouds were passing by. Numerical stimulations were performed to study the evolution of the mass distribution in this disk. These simulations were run with the galactic disk initially flat, and different sets of the initial position and velocity of the Magellanic Clouds were considered. One of the most conspicuous observational facts is the warp of the disk of the Milky Way. Results show that the characteristics of this warp are related to the orbit of the Magellanic Clouds.

scholarly journals Modelling the Structure of the Ringed Spiral NGC 4736

1996 ◽  
Vol 157 ◽  
pp. 253-255
Author(s):  
Wim van Driel ◽  
Pieter Mulder ◽  
Françoise Combes
Keyword(s):  
Mass Distribution ◽  
Spiral Structure ◽  
Optical Spectra ◽  
Spectral Lines ◽  
Time Interval ◽  
Limited Time ◽  
The Galaxy ◽  
Dynamical Simulations ◽  
Pattern Speed ◽  
Limited Time Interval

AbstractWe studied the ringed RSab(r)-type spiral NGC 4736, which has a probably slightly oval disk and a very small bar. We mapped the galaxy in the HI and Hα spectral lines and we obtained long-slit optical spectra. These data were modeled using a 2-D gas dynamical code. The 2-D potential used is axisymmetric in the inner and outer regions and oval (b/a=0.8) at intermediate radii only. The oval component rotates at a pattern speed of 40 km s–1 kpc–1, close to the observed value. Inner and outer rings, like those observed, form at the inner and outer Lindblad resonances, though they co-exist only during a limited time interval in the simulations. The morphology and kinematics of the inner ring and spiral structure as observed in neutral and ionized hydrogen can be well understood in terms of gas dynamical simulations, given the form of the (stellar) potential. What remains to be explained is the origin of the nonaxisymmetric features in the mass distribution defining the potential.

Studying the Patterns of the Universe

2011 ◽  
Vol 20 (2) ◽  
Author(s):  
T. Sepp ◽  
E. Tempel ◽  
M. Gramann ◽  
P. Nurmi ◽  
M. Haupt
Keyword(s):  
Dark Matter ◽  
Galaxy Cluster ◽  
Analytical Models ◽  
Matter Distribution ◽  
Galaxy Groups ◽  
The Galaxy ◽  
Dark Matter Distribution ◽  
Distribution Studies ◽  
The Universe ◽  
Good Agreement

AbstractThe SDSS galaxy catalog is one of the best databases for galaxy distribution studies. The SDSS DR8 data is used to construct the galaxy cluster catalog. We construct the clusters from the calculated luminosity density field and identify denser regions. Around these peak regions we construct galaxy clusters. Another interesting question in cosmology is how observable galaxy structures are connected to underlying dark matter distribution. To study this we compare the SDSS DR7 galaxy group catalog with galaxy groups obtained from the semi-analytical Millennium N-Body simulation. Specifically, we compare the group richness, virial radius, maximum separation and velocity dispersion distributions and find a relatively good agreement between the mock catalog and observations. This strongly supports the idea that the dark matter distribution and galaxies in the semi-analytical models and observations are very closely linked.

scholarly journals An Upper Limit to the Mass Loss from the Centre of the Galaxy

1974 ◽  
Vol 64 ◽  
pp. 36-36
Author(s):  
Arcadio Poveda ◽  
Christine Allen
Keyword(s):  
Mass Loss ◽  
Gravitational Waves ◽  
Mass Distribution ◽  
Globular Clusters ◽  
Loss Rate ◽  
Galactic Centre ◽  
Isotropic Source ◽  
The Past ◽  
Upper Limit ◽  
The Galaxy

A mass loss of 200 M⊙ per year, as conservatively suggested if Weber is detecting gravitational waves from an isotropic source at the galactic centre, is shown to be incompatible with the existence of (a) globular clusters, (b) old wide binaries, if this loss rate has been constant over the past 1010 yr.From the orbit of ω Centauri in the galactic field and its observed mass distribution and tidal radius an upper limit to the mass loss from the galactic centre is found to be 1 M⊙ yr-1 over the past 1010 yr.

scholarly journals The Dark Blue Compact Dwarf Galaxy NGC 2915

1997 ◽  
Vol 14 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Gerhardt R. Meurer
Keyword(s):  
Dark Matter ◽  
Mass Distribution ◽  
Dwarf Galaxy ◽  
Dark Matter Halo ◽  
High Mass ◽  
Mass Star ◽  
Normal Galaxies ◽  
The Galaxy ◽  
Dark Blue ◽  
Blue Compact Dwarf Galaxy

AbstractRecent results on NGC 2915, the first blue compact dwarf galaxy to have its mass distribution modelled, are summarised. NGC 2915 is shown to have HI well beyond its detected optical extent. Its rotation curve is well determined and fit with maximum disk mass models. The dark matter halo dominates the mass distribution at nearly all radii, and has a very dense core compared to those of normal galaxies. High-mass star formation energises the HI in the centre of the galaxy, but appears to be maintained in viriai equilibrium with the dark matter halo. The implications of these results are briefly discussed.

Constraining Galaxy Formation Epoch

2005 ◽  
Vol 201 ◽  
pp. 536-537
Author(s):  
Sukyoung. Yi ◽  
T. Brown ◽  
S. Heap ◽  
I. Hubeny ◽  
W. Landsman ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
High Redshift ◽  
Population Synthesis ◽  
High Redshift Galaxies ◽  
The Galaxy ◽  
The Difference ◽  
Age Estimates ◽  
Good Agreement ◽  
Redshift Galaxies

Pinning down the ages of high redshift galaxies is the most direct way of constraining the galaxy formation epoch. There has been a debate on the age of LBDS 53W091, a red galaxy at z=1.5. The discrepancy in the age estimates of various groups is due to the difference in the population synthesis model. However, there is generally a good agreement among popular models. Polishing the models and assessing their internal uncertainties are crucial in the analysis of high redshift galaxies.

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