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Related papers: Triaxial Orbit-based Models Of Elliptical Galaxies

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In a previous paper, using ergodic theory, Lo [1] derived a simple definite integral that provided an estimate of the view periods of ground stations to satellites. This assumes the satellites are in circular orbits with non-repeating…

Earth and Planetary Astrophysics · Physics 2020-10-14 Andrew J. Graven , Martin W. Lo

Accurate modeling of gravitational interactions is fundamental to the analysis, prediction, and control of space systems. While the Newtonian point-mass approximation suffices for many preliminary studies, real celestial bodies exhibit…

Earth and Planetary Astrophysics · Physics 2026-01-27 Felipe Arenas-Uribe

(abridged) We present a statistical study of the low-mass X-ray binary (LMXB) populations of three nearby, old elliptical galaxies: NGC 3379, NGC 4278, and NGC 4697. With a cumulative ~1 Ms Chandra ACIS observing time, we detect 90-170…

In our previous paper, we developed an orbit-superposition method for edge-on barred galaxies and constructed a set of dynamical models based on different mock observations of three galaxies from the Auriga simulations. In this study, we…

Astrophysics of Galaxies · Physics 2026-03-10 Yunpeng Jin , Ling Zhu , Behzad Tahmasebzadeh , Shude Mao , Glenn van de Ven , Timothy A. Davis

We have constructed fully self-consistent models of triaxial galaxies with central density cusps. The triaxial generalizations of Dehnen's spherical models are presented, which have densities that vary as 1/r^gamma near the center and 1/r^4…

Astrophysics · Physics 2009-10-28 David Merritt , Tema Fridman

We built three models for the gravitational field of the Galactic bar. These models are an inhomogeneous ellipsoid, an inhomogeneous prolate spheroid, and a superposition of four inhomogeneous ellipsoids. Among the three models, the…

Astrophysics · Physics 2009-11-10 Barbara Pichardo , Marco Martos , Edmundo Moreno

Made-to-measure methods such as the parallel code NMAGIC are powerful tools to build galaxy models reproducing observational data. They work by adapting the particle weights in an N-body system until the target observables are well matched.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Lucia Morganti , Ortwin Gerhard

We describe a technique that uses radial color gradients in disk galaxies to detect the presence of bulk non-circular motion or elliptical orbits. In a disk galaxy with both a radial color gradient and non-circular motion, isochromes or…

Astrophysics · Physics 2016-08-15 A. C. Quillen , Solange V. Ramírez , Jay A. Frogel

We propose a physically motivated and self-consistent prescription for the modeling of transient neutron star (NS) low-mass X-ray binary (LMXB) properties, such as duty cycle (DC), outburst duration and recurrence time. We apply this…

Self-consistent solutions for triaxial mass models are highly non-unique. In general, some of these solutions might be dynamically unstable, making them inappropriate as descriptions of steady-state galaxies. Here we demonstrate for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Fabio Antonini , Roberto Capuzzo-Dolcetta , David Merritt

We study a possible formation mechanism for elliptical/S0 galaxies using N-body simulations with GRAPE. A close galaxy encounter which does not lead to a merger can induce a strong bar in an initially axisymmetric disk. This bar is unstable…

Astrophysics · Physics 2007-05-23 Thorsten Naab , Andreas Burkert

Context. The potential field source surface model is frequently used as a basis for further scientific investigations where a comprehensive coronal magnetic field is of importance. Its parameters, especially the position and shape of the…

Solar and Stellar Astrophysics · Physics 2020-07-01 Martin Kruse , Verena Heidrich-Meisner , R. F. Wimmer-Schweingruber , Michael Hauptmann

The dynamics of an elliptical galaxy within a couple of effective radii can be probed effectively by stars. However, at larger distances planetary nebulae (PNe) replace stars as the tracer of the dynamics. Making use of the motion of PNe,…

Astrophysics of Galaxies · Physics 2016-07-15 Yong Tian , Chung-Ming Ko

We present results from a new and unique integral-field spectrograph, SAURON. It has a large field of view and high throughput and is primarily built for the study of stellar & gaseous kinematics and stellar populations in galaxies. Its aim…

In this work we offer an approach to enlarge the number of exactly solvable models with two real scalar fields in (1+1)D. We build some new two-field models, and obtain their exact orbits and exact or numerical field configurations. It is…

High Energy Physics - Theory · Physics 2015-06-19 G. P. de Brito , A. de Souza Dutra

Very high quality light curves are now available for thousands of detached eclipsing binary stars and transiting exoplanet systems as a result of surveys for transiting exoplanets and other large-scale photometric surveys. I have developed…

Instrumentation and Methods for Astrophysics · Physics 2016-06-22 P. F. L. Maxted

We study generalization of median triangles on the plane with two complex parameters. By specialization of the parameters, we produce periodical motion of a triangle whose vertices trace each other on a common closed orbit.

Metric Geometry · Mathematics 2020-09-15 Hiroaki Nakamura , Hiroyuki Ogawa

We explore the use of the tangential component of weak lensing shear to characterize the ellipticity of clusters of galaxies. We introduce an ellipticity estimator, and quantify its properties for isolated clusters from LCDM N-body…

Astrophysics · Physics 2009-11-13 A. E. Schulz , Joseph Hennawi , Martin White

Gauss-Hermite and Gauss-Laguerre ("shapelet") decompositions of images have become important tools in galaxy modeling, particularly for the purpose of extracting ellipticity and morphological information from astronomical data. However, the…

Instrumentation and Methods for Astrophysics · Physics 2010-08-24 James Bosch

In hierarchical models of galaxy formation, ellipticals form from the merging of disk galaxies drawn together by gravity as their surrounding dark halos coalesce. Using semi-analytic techniques, we are able to follow the merging, star…

Astrophysics · Physics 2007-05-23 Guinevere Kauffmann , Stephane Charlot