The Smaller Alignment Index (SALI) applied in a study of stellar orbits in barred galaxies potential models using the LP-VIcode

New Astronomy ◽  
2018 ◽  
Vol 60 ◽  
pp. 48-60 ◽  
Author(s):  
Lucas Antonio Caritá ◽  
Irapuan Rodrigues ◽  
Ivânio Puerari ◽  
Luiz Eduardo Camargo Aranha Schiavo
Keyword(s):  
Potential Models ◽  
Stellar Orbits ◽  
Barred Galaxies

scholarly journals Stellar Orbits in Barred Galaxies with Nuclear Rings

1996 ◽  
Vol 157 ◽  
pp. 467-469
Author(s):  
Clayton H. Heller ◽  
Isaac Shlosman
Keyword(s):  
Large Range ◽  
Symmetric Pair ◽  
Dynamical Response ◽  
Instability Strip ◽  
Stellar Orbits ◽  
Barred Galaxies ◽  
Jacobi Integral ◽  
Elliptical Ring ◽  
Lindblad Resonance ◽  
Inner Lindblad Resonance

AbstractWe investigate the dynamical response of stellar orbits in a rotating barred galaxy potential to the perturbation by a nuclear gaseous ring. The change in 3D periodic orbit families is examined as the gas accumulates near the inner Lindblad resonance. It is found that the x2/x3 loop extends to higher Jacobi energy and a vertical instability strip forms in each family. These strips are connected by a symmetric/anti-symmetric pair of 2:2:1 3D orbital families. A significant distortion of the x1 orbits is observed in the vicinity of the ring, which leads to the intersection between orbits over a large range of the Jacobi integral. We also find that a moderately elliptical ring oblique to the stellar bar produces significant phase shifts in the x1 orbital response.

scholarly journals Stellar Orbits in Doubly-Barred Galaxies

1996 ◽  
Vol 157 ◽  
pp. 464-466
Author(s):  
H. Hasan
Keyword(s):  
Galactic Center ◽  
Observational Evidence ◽  
Stellar Kinematics ◽  
Stellar Orbits ◽  
Barred Galaxies ◽  
Secular Evolution

The question of bars within bars has been reviewed by Friedli and Martinet (1993), who have also performed N-body simulations to produce nested bars. They propose that if a system of embedded bars is effective in transporting gas to the galactic center (Shlosman et al. 1989), then it is perhaps a step in the secular evolution of barred galaxies. In order to pursue this interesting proposition, and also because observational evidence for the existence of secondary bars is mounting (e.g. Buta & Crocker 1993; Shaw et al. 1993, Wozniak et al. 1995), it is important to understand the stellar kinematics in such systems.

scholarly journals Gas-driven evolution of stellar orbits in barred galaxies

1998 ◽  
Vol 300 (1) ◽  
pp. 49-63 ◽  
Author(s):  
I. Berentzen ◽  
C. H. Heller ◽  
I. Shlosman ◽  
K. J. Fricke
Keyword(s):  
Stellar Orbits ◽  
Barred Galaxies

The galactic habitable zone in barred galaxies

2006 ◽  
Vol 5 (4) ◽  
pp. 325-326 ◽  
Author(s):  
M. Sundin
Keyword(s):  
Angular Momentum ◽  
Milky Way ◽  
Habitable Zone ◽  
Escape Velocity ◽  
Stellar Orbits ◽  
Barred Galaxies ◽  
The Galaxy ◽  
Pattern Speed ◽  
Disc Galaxies ◽  
High Metallicity

One of the criteria for the concept of a galactic habitable zone (GHZ) is that the pattern speed of the stars in the GHZ should be close to the pattern speed of the spiral arms. Another criteria is that the stars in it should have a high enough metallicity. In a barred galaxy, the GHZ will be more complicated to define since the bar can change stellar orbits. Many disc galaxies, including the Milky Way, are barred galaxies. The stars in the bar move in a number of fairly complicated orbits. However, the bar will also influence the orbits of stars in the whole galaxy. Stars passing close to the bar can either gain or lose angular momentum, due to a positive or negative torque by the bar. Some stars will therefore be captured by the bar while some stars eventually may reach the escape velocity from the galaxy. The bar will hence be able to relocate stars, and stars with low or high metallicity could be found far away from their original orbits. The ordinary evolution of a bar is to grow in length out to the co-rotation radius for the pattern speed of the bar. As the galaxy ages, and the bar grows in length, the bar will influence a larger part of the galaxy. The effect of moving stars inwards or outwards is greatest just outside the bar, and this region can eventually lose a high percentage of the stars.

11. Galactic Dynamics: Stellar Orbits

1988 ◽  
Vol 20 (01) ◽  
pp. 404-405
Keyword(s):  
Degrees Of Freedom ◽  
Elliptical Galaxies ◽  
Galactic Dynamics ◽  
Meridional Plane ◽  
Integrals Of Motion ◽  
Chaotic Motions ◽  
Stellar Orbits ◽  
Barred Galaxies ◽  
The Individual ◽  
Three Degrees Of Freedom

The interest in stellar orbits focussed on two areas: Firstly, on the existence of non-classical integrals of motion (“third integral”) and on the occurence of stochastic or chaotic motions in systems with two or three degrees of freedom. While the case of three degrees of freedom is the more realistic one, results on systems with only two degrees of freedom can be applied to situations such as the motions of stars in the co-moving meridional plane of axisymmetric galaxies or in the equatorial plane of spiral or barred galaxies. Secondly, there is continuing interest in the orbital motions of stars in triaxial systems, which may represent either triaxial elliptical galaxies or galactic bars. The ultimate aim of many of the studies on stellar orbits is to build self-consistent models of stellar systems on the basis of the individual orbits of the stars.

Semi-relativistic quark-antiquark potential models

1985 ◽  
Vol 10 (5) ◽  
pp. 475-522 ◽  
Author(s):  
J.L. Basdevant ◽  
S. Boukraa
Keyword(s):  
Potential Models

scholarly journals MONITORING STELLAR ORBITS AROUND THE MASSIVE BLACK HOLE IN THE GALACTIC CENTER

2009 ◽  
Vol 692 (2) ◽  
pp. 1075-1109 ◽  
Author(s):  
S. Gillessen ◽  
F. Eisenhauer ◽  
S. Trippe ◽  
T. Alexander ◽  
R. Genzel ◽  
...  
Keyword(s):  
Black Hole ◽  
Galactic Center ◽  
Massive Black Hole ◽  
Stellar Orbits

scholarly journals Birth sites of young stellar associations and recent star formation in a flocculent corrugated disc

2020 ◽  
Vol 499 (4) ◽  
pp. 5623-5640
Author(s):  
Alice C Quillen ◽  
Alex R Pettitt ◽  
Sukanya Chakrabarti ◽  
Yifan Zhang ◽  
Jonathan Gagné ◽  
...  
Keyword(s):  
Space Distribution ◽  
Solar Neighbourhood ◽  
Low Velocity ◽  
Stellar Association ◽  
Stellar Orbits ◽  
Pattern Speeds ◽  
Moving Groups ◽  
Orbit Integration ◽  
Stellar Associations ◽  
Spiral Arm

ABSTRACT With backwards orbit integration, we estimate birth locations of young stellar associations and moving groups identified in the solar neighbourhood that are younger than 70 Myr. The birth locations of most of these stellar associations are at a smaller galactocentric radius than the Sun, implying that their stars moved radially outwards after birth. Exceptions to this rule are the Argus and Octans associations, which formed outside the Sun’s galactocentric radius. Variations in birth heights of the stellar associations suggest that they were born in a filamentary and corrugated disc of molecular clouds, similar to that inferred from the current filamentary molecular cloud distribution and dust extinction maps. Multiple spiral arm features with different but near corotation pattern speeds and at different heights could account for the stellar association birth sites. We find that the young stellar associations are located in between peaks in the radial/tangential (UV) stellar velocity distribution for stars in the solar neighbourhood. This would be expected if they were born in a spiral arm, which perturbs stellar orbits that cross it. In contrast, stellar associations seem to be located near peaks in the vertical phase-space distribution, suggesting that the gas in which stellar associations are born moves vertically together with the low-velocity dispersion disc stars.

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