The solution of poisson's equation for isolated source distributions

James, R. A.

doi:10.1016/0021-9991(77)90013-4

Cited by 122 publications

(81 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both scenarios are known to form polar structures (see Reshetnikov & Sotnikova 1997;Bekki 1997Bekki , 1998. The numerical code computes the gravitational potential via a fast Fourier transform (FFT) method (James 1977) and includes stickyparticle gasdynamics (Schwarz 1981) and star formation that is assumed to obey a generalized Schmidt law (Schmidt 1959). Both scenarios for formation of polar rings give similar results for the kinematics of the ring after its formation.…”

Section: Figsupporting

confidence: 51%

Polar Ring Galaxies and the Tully‐Fisher Relation: Implications for the Dark Halo Shape

Iodice¹,

Arnaboldi²,

Bournaud³

et al. 2003

ApJ

View full text Add to dashboard Cite

We have investigated the Tully-Fisher relation for polar ring galaxies (PRGs), based on near-infrared, optical, and H i data available for a sample of these peculiar objects. The total K-band luminosity, which mainly comes from the central host galaxy, and the measured H i line width at 20% of the peak line flux density, which traces the potential in the polar plane, place most polar rings in the sample far from the TullyFisher relation defined for spiral galaxies, with many PRGs showing larger H i line widths than expected for the observed K-band luminosity. This result is confirmed by a larger sample of objects, based on B-band data. This observational evidence may be related to the dark halo shape and orientation in these systems, which we study by numerical modeling of PRG formation and dynamics: the larger rotation velocities observed in PRGs can be explained by a flattened polar halo, aligned with the polar ring.

show abstract

Section: Figsupporting

confidence: 51%

Polar Ring Galaxies and the Tully‐Fisher Relation: Implications for the Dark Halo Shape

Iodice¹,

Arnaboldi²,

Bournaud³

et al. 2003

ApJ

View full text Add to dashboard Cite

show abstract

“…The gravitational potential is calculated at the nodes of a three-dimensional 128 × 128 ×64 cartesian grid, providing a resolution of 1 kpc. Effective use is made of the entire grid, rather than of only one eighth in standard Fourier algorithms, through implementation of a method described by James (1977).…”

Section: The Modelmentioning

confidence: 99%

Stars and gas in the very large interacting galaxy NGC 6872

Horellou¹,

Koribalski²

2006

A&A

View full text Add to dashboard Cite

The dynamical evolution of the large (>100 kpc), barred spiral galaxy NGC 6872 and its small companion IC 4970 in the southern group Pavo is investigated. We present N-body simulations with stars and gas and 21 cm Hi observations carried out with the Australia Telescope Compact Array of the large-scale distribution and kinematics of atomic gas. Hi is detected toward the companion, corresponding to a gas mass of ∼1.3 × 10 9 M . NGC 6872 contains ∼1.4 × 10 10 M of Hi gas, distributed in an extended rotating disk. Massive concentrations of gas (∼10 9 M ) are found at the tip of both tidal tails and towards the break seen in the optical northern arm near the companion. We detect no Hi counterpart to the X-ray trail between NGC 6872 and NGC 6876, the dominant elliptical galaxy in the Pavo group located ∼8 to the southeast. At the sensitivity and the resolution of the observations, there is no sign in the overall Hi distribution that NGC 6876 has affected the evolution of NGC 6872. There is no evidence of ram pressure stripping either. The X-ray trail could be due to gravitational focusing of the hot gas in the Pavo group behind NGC 6872 as the galaxy moves supersonically through the hot medium. The simulations of a gravitational interaction with a small nearby companion on a low-inclination prograde passage are able to reproduce most of the observed features of NGC 6872, including the general morphology of the galaxy, the inner bar, the extent of the tidal tails and the thinness of the southern tail.

show abstract

“…The N-body code used is an FFT algorithm, using the method of James (1977) to avoid the periodic images. With N = 150,000 particles, it required 2.7 seconds of CPU per time step on a Cray-C94.…”

Section: Numerical Simulationsmentioning

confidence: 99%

Internal dynamics of globular clusters

Meylan

Heggie

1997

Astronomy and Astrophysics Review

421

394

View full text Add to dashboard Cite

Galactic globular clusters are ancient building blocks of our Galaxy. They represent a very interesting family of stellar systems in which some fundamental dynamical processes have been taking place for more than 10 Gyr, but on time scales shorter than the age of the universe. In contrast with galaxies, these star clusters represent unique laboratories for learning about two-body relaxation, mass segregation from equipartition of energy, stellar collisions, stellar mergers, core collapse, and tidal disruption. This review briefly summarizes some of the tremendous developments that have taken place during the last two decades. It ends with some recent results on tidal tails around galactic globular clusters and on a very massive globular cluster in M31. IntroductionThere are about 150 globulars orbiting in the halo of our Galaxy. They look like huge swarms of stars, characterized by symmetry and apparent smoothness. Fig. 1 below displays an image of NGC 5139 ≡ ω Centauri, the brightest and most massive galactic globular cluster. This 40 ′ by 40 ′ image from the Digital Sky Survey does not reach, in spite of its rather large angular size, the outer parts of the cluster. With its tidal radius of about 40-50 ′ , the apparent diameter of ω Centauri on the plane of the sky is significantly larger than the apparent 30 ′ diameter of the full moon. Globular clusters are old stellar systems, made of one single generation of stars. Although still somewhat uncertain, their individual ages range between about 10 and 15 Gyr, with possible significant differences, up to a few gigayears, from one cluster to the other. Other properties of globular clusters exhibit significant variations: e.g., their integrated absolute magnitudes range from M int V = -1.7 to -10.1 mag; their total masses from M tot = 10 3 to 5 × 10 6 M ⊙ ; their galactocentric distances from 2 to 120 kpc. 2A few dynamical time scalesThe dynamics of any stellar system may be characterized by the following three dynamical time scales: (i) the crossing time t cr , which is the time needed by a star to move across the system; (ii) the relaxation time t rlx , which is the meylanreview:

show abstract

The solution of poisson's equation for isolated source distributions

Cited by 122 publications

References 10 publications

Polar Ring Galaxies and the Tully‐Fisher Relation: Implications for the Dark Halo Shape

Polar Ring Galaxies and the Tully‐Fisher Relation: Implications for the Dark Halo Shape

Stars and gas in the very large interacting galaxy NGC 6872

Internal dynamics of globular clusters

Contact Info

Product

Resources

About