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Related papers: Axisymmetric Three-Integral Models for Galaxies

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We present a two-dimensional (2-D) fitting algorithm (GALFIT) designed to extract structural components from galaxy images, with emphasis on closely modeling light profiles of spatially well-resolved, nearby galaxies observed with the…

Astrophysics · Physics 2011-05-05 Chien Y. Peng , Luis C. Ho , Chris D. Impey , Hans-Walter Rix

Eigenmode analysis is one of the most promising methods of analyzing large data sets in ongoing and near-future galaxy surveys. In such analyses, a fast evaluation of the correlation matrix in arbitrary cosmological models is crucial. The…

Astrophysics · Physics 2009-11-10 Takahiko Matsubara , Alexander S. Szalay , Adrian C. Pope

Aims: We aim to develop an algorithm for constructing equilibrium initial conditions for simulations of disk galaxies with a triaxial halo and/or a gaseous component. This will pave the way for N-body simulations of realistic disk galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-16 S. A. Rodionov , E. Athanassoula

In this article we model a Global Navigation Satellite System (GNSS) in a Schwarzschild space-time, as a first approximation of the relativistic geometry around the Earth. The closed time-like and scattering light-like geodesics are…

General Relativity and Quantum Cosmology · Physics 2015-05-18 P. Delva , U. Kostic , A. Cadez

Observational astronomy relies on visual feature identification to detect critical astrophysical phenomena. While machine learning (ML) increasingly automates this process, models often struggle with generalization in large-scale surveys…

Astrophysics of Galaxies · Physics 2026-01-15 Chenrui Ma , Zechang Sun , Tao Jing , Zheng Cai , Yuan-Sen Ting , Song Huang , Mingyu Li

We construct numerical models of mildly triaxial elliptical galaxies with central density cusps. Using a technique we call ``adiabatic squeezing'', we begin with a spherical gamma=1 Hernquist model and apply a drag to the velocities of the…

Syer and Tremaine's made-to-measure method and Schwarzschild's orbit superposition method are well-known within the field of stellar dynamical modeling. This research is concerned with assessing and comparing the operational capabilities of…

Astrophysics of Galaxies · Physics 2026-01-22 Richard J. Long

We present an inverse method for designing a three-dimensional imaging system comprising of freeform optical surfaces. We impose an imaging condition on the optical map and combine it with the law of conservation of energy to conclude that…

We employ the minimal geometric deformation approach to gravitational decoupling (MGD-decoupling) in order to generate an exact anisotropic and non-uniform version of the ultracompact Schwarzschild star, or 'gravastar', proposed by Mazur…

General Relativity and Quantum Cosmology · Physics 2020-09-25 J. Ovalle , C. Posada , Z. Stuchlík

Context. Dynamically self-consistent galactic models are necessary for analysing and interpreting star counts, stellar density distributions, and stellar kinematics in order to understand the formation and the evolution of our Galaxy. Aims.…

Astrophysics of Galaxies · Physics 2018-12-12 Olivier Bienaymé , Jérome Leca , Annie C. Robin

We explore the capability of deep learning to classify cosmic structures. In cosmological simulations, cosmic volumes are segmented into voids, sheets, filaments and knots, according to the distribution and kinematics of dark matter (DM),…

Astrophysics of Galaxies · Physics 2022-08-03 Shigeki Inoue , Xiaotian Si , Takashi Okamoto , Moka Nishigaki

The study of strong-lensing systems conventionally involves constructing a mass distribution that can reproduce the observed multiply-imaging properties. Such mass reconstructions are generically non-unique. Here, we present an alternative…

Astrophysics of Galaxies · Physics 2021-06-30 Philipp Denzel , Sampath Mukherjee , Prasenjit Saha

Galaxy spectra are a rich source of kinematical information since the shapes of the absorption lines reflect the movement of stars along the line-of-sight. We present a technique to directly build a dynamical model for a galaxy by fitting…

Astrophysics · Physics 2009-10-30 S. De Rijcke , H. Dejonghe

Image simulations are essential tools for preparing and validating the analysis of current and future wide-field optical surveys. However, the galaxy models used as the basis for these simulations are typically limited to simple parametric…

Instrumentation and Methods for Astrophysics · Physics 2021-05-12 Francois Lanusse , Rachel Mandelbaum , Siamak Ravanbakhsh , Chun-Liang Li , Peter Freeman , Barnabas Poczos

Gas-poor galaxies can be modelled as composite collisionless stellar systems, with a dark matter halo and one or more stellar components, representing different stellar populations. The dynamical evolution of such composite systems is often…

Astrophysics of Galaxies · Physics 2021-03-24 Carlo Nipoti , Giacomo Cherchi , Giuliano Iorio , Francesco Calura

Cosmological galaxy formation simulations are powerful tools to understand the complex processes that govern the formation and evolution of galaxies. However, evaluating the realism of these simulations remains a challenge. The two common…

We introduce a diffusion-based generative model to describe the distribution of galaxies in our Universe directly as a collection of points in 3-D space (coordinates) optionally with associated attributes (e.g., velocities and masses),…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-24 Carolina Cuesta-Lazaro , Siddharth Mishra-Sharma

Among dynamical modeling techniques, the made-to-measure (M2M) method for modeling steady-state systems is among the most flexible, allowing non-parametric distribution functions in complex gravitational potentials to be modeled efficiently…

Astrophysics of Galaxies · Physics 2017-11-28 Jo Bovy , Daisuke Kawata , Jason A. S. Hunt

Fitting equilibrium dynamical models to observational data is an essential step in understanding the structure of the gaseous hot haloes that surround our own and other galaxies. However, the two main categories of models that are used in…

Astrophysics of Galaxies · Physics 2018-09-26 Mattia C. Sormani , Emanuele Sobacchi , Gabriele Pezzulli , James Binney , Ralf S. Klessen

We study the stellar response in a spectrum of potentials describing the barred spiral galaxy NGC 1300. These potentials have been presented in a previous paper and correspond to three different assumptions as regards the geometry of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 C. Kalapotharakos , P. A. Patsis , P. Grosbol