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Related papers: A New Model for the Milky Way Bar

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In this paper we analyse the methodology to derive the bar pattern speed from dynamical simulations. The results are robust to the changes in the vertical-scale height and in the mass-to-light (M/L) ratios. There is a small range of…

Astrophysics of Galaxies · Physics 2010-02-08 I. Perez , K. C. Freeman , R. Fux , A. Zurita

Action-based dynamical modelling, using stars as dynamical tracers, is an excellent diagnostic to estimate the underlying axisymmetric matter distribution of the Milky Way. However, the Milky Way's bar causes non-axisymmetric resonance…

Astrophysics of Galaxies · Physics 2023-06-27 Soumavo Ghosh , Wilma H. Trick , Gregory M. Green

We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the…

Astrophysics · Physics 2009-11-10 M. Martos , X. Hernandez , M. Yanez , E. Moreno , B. Pichardo

Both the three-dimensional density of red clump giants and the gas kinematics in the inner Galaxy indicate that the pattern speed of the Galactic bar could be much lower than previously estimated. Here, we show that such slow bar models are…

Astrophysics of Galaxies · Physics 2016-12-21 Giacomo Monari , Benoit Famaey , Arnaud Siebert , Aurore Duchateau , Thibault Lorscheider , Olivier Bienaymé

The arguments in favor of the unified formation mechanism for both slow (Lynden-Bell's) bars and common fast bars are given. This mechanism consists in a certain instability that is akin to the well-known radial orbit instability; it is…

Astrophysics · Physics 2007-05-23 E. V. Polyachenko , V. L. Polyachenko

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

We present a new method for fitting simple hydrodynamical models to the (l,v) distribution of atomic and molecular gas observed in the Milky Way. The method works by matching features found in models and observations. It is based on the…

Astrophysics of Galaxies · Physics 2015-06-23 Mattia C. Sormani , John Magorrian

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

We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and an NFW halo with parameters relevant to the Milky Way Galaxy is subject to bar formation. Taking into account the…

Astrophysics of Galaxies · Physics 2016-08-17 Evgeny Polyachenko , Peter Berczik , Andreas Just

We examine the idea that dynamical parameters can be estimated by identifying locations in the solar neighbourhood where simulated velocity distributions match the observed local distribution. Here, the dynamical influence of both the…

Astrophysics · Physics 2009-11-13 Dalia Chakrabarty

We present a 3D N-body simulation of the Milky Way including 4*10^5 star- and dark-like particles and 2*10^4 gas particles, initially distributed according to an axisymmetric, observationally constrained, mass model. The whole system is…

Astrophysics · Physics 2008-02-03 R. Fux , D. Friedli

This article describes the Schwarzschild orbit superposition method. It is the state-of-the-art dynamical modelling tool for early-type galaxies. Tests with analytic models show that masses and orbital anisotropies of not too face-on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jens Thomas

This paper examines the reliability of the Tremaine-Weinberg (TW) method in measuring the pattern speed of barred galaxies at high redshifts. Measuring pattern speeds at high redshift may help to shed light on the time evolution of…

We present an investigation into the morphological features of the Milky Way. We use smoothed particle hydrodynamics (SPH) to simulate the interstellar medium (ISM) in the Milky Way under the effect of a number of different gravitational…

Astrophysics of Galaxies · Physics 2015-06-22 Alex R. Pettitt , Clare L. Dobbs , David M. Acreman , Daniel J. Price

Red clump giant stars can be used as distance indicators to trace the mass distribution of the Galactic bar. We use RCG stars from 44 bulge fields from the OGLE-II microlensing collaboration database to constrain analytic tri-axial models…

Astrophysics · Physics 2009-06-23 Nicholas J. Rattenbury , Shude Mao , Takahiro Sumi , Martin C. Smith

A new method for determining the nature of the orbital motion (chaotic or regular) of globular clusters in the central region of the Galaxy with a radius of 3.5 kpc, which are most affected by the bar, is proposed. The method is based on…

Astrophysics of Galaxies · Physics 2025-04-30 Anisa Bajkova , Anton Smirnov , Vadim Bobylev

We build a stellar-dynamical model of the Milky Way barred bulge and disk, using a newly implemented adaptive particle method. The underlying mass model has been previously shown to match the Galactic near-infrared surface brightness as…

Astrophysics · Physics 2009-11-10 Nicolai Bissantz , Victor P. Debattista , Ortwin Gerhard

To advance our understanding of the evolution of the interstellar medium (ISM) of our Galaxy, numerical models of Milky Way (MW) type galaxies are widely used. However, most models only vaguely resemble the MW (e.g. in total mass), and…

In this paper, the redshift evolution of the galactic bar properties, like the bar length, pattern speed, and bar fraction, has been investigated for simulated galaxies at stellar masses $M_*>10^{10}\, M_{\odot}$ in the cosmological…

We use Schwarzschild's orbit superposition method to build self-consistent models of elliptical galaxies with scale-free potentials. Our exhaustive study of all physical shapes and central densities for galaxies with scale-free potentials…

Astrophysics · Physics 2007-05-23 Balsa Terzic