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Related papers: Triaxial Orbit-based Models Of Elliptical Galaxies

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We discuss some recent integral field spectroscopy using the SAURON instrument of a sample consisting of 24 early-type spirals, part of the SAURON Survey, and 18 late-type spirals. Using 2-dimensional maps of their stellar radial velocity,…

We show how to construct families of stationary hydrodynamical configurations that reproduce the observed vertical gradient of the rotation velocity of the extra-planar gas in spiral galaxies. We then present a simple model for the lagging…

Astrophysics · Physics 2007-05-23 M. Barnabe' , L. Ciotti , F. Fraternali , R. Sancisi

We present the results from a wide-field imaging study of globular cluster (GC) systems in three early-type galaxies. Combinations of Subaru/Suprime-Cam, CFHT/MegaCam and HST/WFPC2/ACS data were used to determine the GC system properties of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Sreeja S. Kartha , Duncan A. Forbes , Lee R. Spitler , Aaron J. Romanowsky , Jacob A. Arnold , Jean P. Brodie

We present a method for fitting orbit-superposition models to the kinematics of discrete stellar systems when the available stellar sample has been filtered by a known selection function. The fitting method can be applied to any model in…

Astrophysics of Galaxies · Physics 2019-01-23 John Magorrian

A variety of modeling techniques is used with surface photometry from the literature and recently acquired high-accuracy stellar kinematic data to constrain the three-dimensional mass distribution in the luminous cuspy elliptical galaxy NGC…

Astrophysics · Physics 2009-10-31 Thomas S. Statler , Herwig Dejonghe , Tammy Smecker-Hane

I present various projects to study the halo dynamics of elliptical galaxies. This allows one to study the outer mass and orbital distributions of ellipticals in different environments, and the inner distributions of groups and clusters…

Astrophysics · Physics 2015-06-24 Aaron J. Romanowsky

We present direct observational constraints on the orbital distribution of the stars in the giant elliptical NGC 2320. Long-slit spectra along multiple position angles are used to derive the stellar line-of-sight velocity distribution…

Astrophysics · Physics 2009-10-31 Nicolas Cretton , Hans-Walter Rix , Tim de Zeeuw

Using the orbit method we attempt to reveal geometric and algebraic meaning of separation of variables for the integrable systems on coadjoint orbits in an $\mathfrak{sl}(3)$ loop algebra. We consider two types of generic orbits embedded…

Exactly Solvable and Integrable Systems · Physics 2016-11-03 Julia Bernatska , Petro Holod

The 3D mass distributions of galaxy clusters are generally triaxial, a geometry that is difficult to constrain from projected observations. In this work, we measure the projected halo shapes of clusters from their weak lensing signatures…

Diffusion-based generative models represent the current state-of-the-art for image generation. However, standard diffusion models are based on Euclidean geometry and do not translate directly to manifold-valued data. In this work, we…

Machine Learning · Computer Science 2023-12-20 Yesukhei Jagvaral , Francois Lanusse , Rachel Mandelbaum

Tests of cosmological models via measurements of galaxy correlations will require increasing modeling accuracy, given the high precision of measurements promised by forthcoming galaxy surveys. In this work we investigate the biases…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-06 Francesco Spezzati , Alvise Raccanelli

We determine the values of parameters of an N-body model for the Galaxy developed by Fux via comparison with an unbiased, homogeneous sample of OH/IR stars. Via Monte-Carlo simulation, we find the plausibilities of the best-fitting models,…

Astrophysics · Physics 2009-10-31 M. Sevenster , P. Saha , D. Valls-Gabaud , R. Fux

A new potential is presented for spherical galaxies. The technique of the construction of our model is similar to that given by An and Evans. In a special case, its mass density becomes a special one of the Hernquist model. Another special…

Astrophysics of Galaxies · Physics 2025-03-11 Zhenglu Jiang , Zanchen Zhuo

As a large-scale overdensity collapses, it affects the orientation and shape of galaxies that form, by exerting tidal shear along their axes. Therefore, the shapes of elliptical galaxies align with the tidal field of cosmic structures. This…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-10 Eleni Tsaprazi , Nhat-Minh Nguyen , Jens Jasche , Fabian Schmidt , Guilhem Lavaux

In this paper, a surface geometric constraint approach is used in designing the orbits of a solar sail. We solve the solar sail equation of motion by obtaining a generalized Laplace-Runge-Lenz (LRL) vector with the assumption that the cone…

Instrumentation and Methods for Astrophysics · Physics 2023-05-03 Jeric Garrido , Jose Perico Esguerra

The images of relativistic jets from extragalactic sources produced by gravitational lensing by galaxies with different mass surface density distributions are modeled. In particular, the following models of the gravitational lens mass…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 T. I. Larchenkova , A. A. Lutovinov , N. S. Lyskova

We analyse the orbital distribution of E and S0 galaxies using SAURON integral-field stellar kinematics. We construct the anisotropy (V/sigma,epsilon) diagram, for the 48 E/S0 galaxies from the SAURON survey. For a subsample of 24 galaxies…

In the first paper of this series we used the N--body method to build a dozen cuspy (gamma ~ 1) triaxial models of stellar systems, and we showed that they were highly stable over time intervals of the order of a Hubble time, even though…

Astrophysics of Galaxies · Physics 2015-06-11 J. C. Muzzio , H. D. Navone , A. F. Zorzi

In this paper, we overlay a continuum of analytical relations which essentially serve to compute the arc-length described by a celestial body in an elliptic orbit within a stipulated time interval. The formalism is based upon a…

Computational Physics · Physics 2019-11-26 Aayush Jha , Ashim B. Karki

{Abridged} We show that the surface brightness (SB) profiles of elliptical galaxies can be parametrized using a linear superposition of 2-3 components, described by functions developed in Dhar & Williams as the 2D projections of a 3D…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Barun Kumar Dhar , Liliya L. R. Williams