scholarly journals The nature of orbits in a prolate elliptical galaxy model with a bulge and a dense nucleus

2011 ◽  
Vol 11 (12) ◽  
pp. 1449-1456 ◽  
Author(s):  
Nicolaos D. Caranicolas ◽  
Euaggelos E. Zotos
Keyword(s):  
Elliptical Galaxy ◽  
Galaxy Model ◽  
Dense Nucleus

scholarly journals A New Dynamical Parameter for the Study of Sticky Orbits in a 3D Galactic Model

2011 ◽  
Vol 20 (3) ◽  
Author(s):  
Euaggelos E. Zotos
Keyword(s):  
Dynamical System ◽  
Classical Method ◽  
Elliptical Galaxy ◽  
Dynamical Model ◽  
Dynamical Parameter ◽  
2D System ◽  
Galactic Model ◽  
Dense Nucleus

AbstractA 3D dynamical model is used to study the motion in the central parts of an elliptical galaxy, hosting a massive and dense nucleus. Our aim is to investigate the regular or chaotic character of the motion, with emphasis in the different chaotic components, as well as the sticky regions of the dynamical system. In order to define the character of the motion in the 2D system, we use the classical method of the Poincaré x − p

scholarly journals The Chemodynamical Evolution of Spheroidal Systems and the Resultant Stellar Abundance Distribution Function

1996 ◽  
Vol 169 ◽  
pp. 425-426
Author(s):  
T. Tsujimoto ◽  
T. Shigeyama ◽  
K. Nomoto
Keyword(s):  
Galaxy Formation ◽  
Thermal Energy ◽  
Elliptical Galaxy ◽  
Three Dimensional ◽  
Galactic Bulge ◽  
Interstellar Gas ◽  
Sph Method ◽  
Relative Ratio ◽  
Galaxy Model ◽  
Formation And Evolution

We construct a chemo-dynamical model for galaxy formation using a three dimensional SPH method. We simulate the formation of two spheroidal systems, i.e., the elliptical galaxy and the Galactic bulge, based on the collapse scenario for protogalaxies. We obtain the chemodynamical formation and evolution models for the two systems during the first ∼ 1 Gyr. The relative ratio of kinetic to thermal energy of supernovae is found to heavily determine the outcome. By giving the explosion energy of supernovae to the interstellar gas with a physically meaningful relative ratio of kinetic to thermal energy, the elliptical galaxy model has the hot halo and the galactic wind, but it is not the case for the Galactic bulge model.

Integrals of Motion in an Elliptical Galaxy Model

1987 ◽  
Vol 127 ◽  
pp. 485-486
Author(s):  
Althea Wilkinson ◽  
Tim de Zeeuw
Keyword(s):  
Distribution Function ◽  
Phase Space ◽  
Numerical Integration ◽  
Spectral Decomposition ◽  
Elliptical Galaxy ◽  
Space Distribution ◽  
Integrals Of Motion ◽  
Phase Space Distribution ◽  
Body Model ◽  
Galaxy Model

The structure of a galaxy model is described completely by its phase–space distribution function f. By Jeans' Theorem f can be written as a function of the integrals of motion admitted by the potential of the model. Various independent combinations of the integrals may be used as arguments of f; in many cases the action integrals are to be preferred. For a general N–body model, these can be obtained by numerical integration and subsequent spectral decomposition of each orbit (Binney and Spergel 1984).

Modeling the Evolution of Disk Galaxies. I. The Chemodynamical Method and the Galaxy Model

1997 ◽  
Vol 476 (2) ◽  
pp. 544-559 ◽  
Author(s):  
M. Samland ◽  
G. Hensler ◽  
Ch. Theis
Keyword(s):  
Disk Galaxies ◽  
The Galaxy ◽  
Galaxy Model

scholarly journals In‐DepthChandraStudy of the AGN Feedback in Virgo Elliptical Galaxy M84

2008 ◽  
Vol 686 (2) ◽  
pp. 911-917 ◽  
Author(s):  
A. Finoguenov ◽  
M. Ruszkowski ◽  
C. Jones ◽  
M. Brüggen ◽  
A. Vikhlinin ◽  
...  
Keyword(s):  
Elliptical Galaxy

scholarly journals WISDOM project – VII. Molecular gas measurement of the supermassive black hole mass in the elliptical galaxy NGC 7052

2021 ◽  
Vol 503 (4) ◽  
pp. 5984-5996
Author(s):  
Mark D Smith ◽  
Martin Bureau ◽  
Timothy A Davis ◽  
Michele Cappellari ◽  
Lijie Liu ◽  
...  
Keyword(s):  
Black Hole ◽  
Hubble Space Telescope ◽  
Elliptical Galaxy ◽  
Continuum Emission ◽  
Molecular Gas ◽  
Supermassive Black Hole ◽  
Gas Kinematics ◽  
Long Baseline ◽  
Gas Measurement ◽  
Strong Gradient

ABSTRACT Supermassive black hole (SMBH) masses can be measured by resolving the dynamical influences of the SMBHs on tracers of the central potentials. Modern long-baseline interferometers have enabled the use of molecular gas as such a tracer. We present here Atacama Large Millimeter/submillimeter Array observations of the elliptical galaxy NGC 7052 at 0${^{\prime\prime}_{.}}$11 ($37\,$pc) resolution in the 12CO(2-1) line and $1.3\,$ mm continuum emission. This resolution is sufficient to resolve the region in which the potential is dominated by the SMBH. We forward model these observations, using a multi-Gaussian expansion of a Hubble Space Telescope F814W image and a spatially constant mass-to-light ratio to model the stellar mass distribution. We infer an SMBH mass of $2.5\pm 0.3\times 10^{9}\, \mathrm{M_\odot }$ and a stellar I-band mass-to-light ratio of $4.6\pm 0.2\, \mathrm{M_\odot /L_{\odot ,I}}$ (3σ confidence intervals). This SMBH mass is significantly larger than that derived using ionized gas kinematics, which however appears significantly more kinematically disturbed than the molecular gas. We also show that a central molecular gas deficit is likely to be the result of tidal disruption of molecular gas clouds due to the strong gradient in the central gravitational potential.

Selection of M-dwarfs using Gaia, WISE, and 2MASS

2019 ◽  
Vol 490 (3) ◽  
pp. 4107-4120
Author(s):  
J Bentley ◽  
C G Tinney ◽  
S Sharma ◽  
D Wright
Keyword(s):  
Absolute Magnitude ◽  
Contamination Rate ◽  
M Dwarfs ◽  
Sky Survey ◽  
Model Predictions ◽  
Galaxy Model ◽  
M Dwarf ◽  
Different Sources ◽  
Sources Of Contamination ◽  
Selection Of

ABSTRACT We present criteria for the selection of M-dwarfs down to G < 14.5 using all-sky survey data, with a view to identifying potential M-dwarfs, to be confirmed spectroscopically by the FunnelWeb survey. Two sets of criteria were developed. The first, based on absolute magnitude in the Gaia G passband, with MG > 7.7, selects 76,392 stars, with 81.0 per cent expected to be M-dwarfs at a completeness of >97 per cent. The second is based on colour and uses Gaia, WISE, and 2MASS all-sky photometry. This criteria identifies 94,479 candidate M-dwarfs, of which between 29.4 per cent and 47.3 per cent are expected to be true M-dwarfs, and which contains 99.6 per cent of expected M-dwarfs. Both criteria were developed using synthetic galaxy model predictions, and a previously spectroscopically classified set of M- and K-dwarfs, to evaluate both M-dwarf completeness and false-positive detections (i.e. the non-M-dwarf contamination rate). Both criteria used in combination demonstrate how each excludes different sources of contamination. We therefore developed a final set of criteria that combines absolute magnitude and colour selection to identify 74,091 stars. All these sets of criteria select numbers of objects feasible for confirmation via massively multiplexed spectroscopic surveys like FunnelWeb.

scholarly journals Progress Report on the Southern Proper Motion Program

1995 ◽  
Vol 166 ◽  
pp. 357-357
Author(s):  
I. Platais ◽  
T. M. Girard ◽  
V. Kozhurina-Platais ◽  
R. A. Mendez ◽  
W. F. Van Altena ◽  
...  
Keyword(s):  
Reference Frame ◽  
Proper Motion ◽  
Systematic Errors ◽  
Progress Report ◽  
Model Choice ◽  
Plate Model ◽  
Field Independent ◽  
The Status ◽  
First Results ◽  
Galaxy Model

We present the status of the Yale/San Juan Southern Proper Motion program (SPM) which is the southern hemisphere extension of the Lick Observatory Northern Proper Motion program with respect to faint galaxies (Platais et al., 1993). To date, measurements and reductions in the South Galactic Pole region comprising ≈ 1000 square-degrees on the sky have been finished. At this stage of the SPM program particular attention has been paid to the plate model choice along with an assessment of and accounting for systematic errors. For our establishing of a secondary reference frame we have noticed the presence of a potentially dangerous effect, so–called field–independent coma which is caused by lens decentering. We acknowledge the superb Hipparcos preliminary positions without which such analysis would be virtually impossible. The SPM data at the SGP region have also been used to constrain a multi–component Galaxy model. First results of this analysis are presented.

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