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Related papers: A New Model for the Milky Way Bar

200 papers

Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models of the Galactic structure. More efforts to build dynamical…

Astrophysics of Galaxies · Physics 2018-07-18 Tatiana A. Michtchenko , Jacques R. D. Lépine , Douglas A. Barros , Ronaldo S. S. Vieira

We present gas flow models for the Milky Way based on high-resolution grid-based hydrodynamical simulations. The basic galactic potential we use is from a N-body model constrained by the density of red clump giants in the Galactic bulge. We…

Astrophysics of Galaxies · Physics 2016-06-15 Zhi Li , Ortwin Gerhard , Juntai Shen , Matthieu Portail , Christopher Wegg

Schwarzschild's orbit-superposition technique is the most developed and well-tested method available for constraining the detailed mass distributions of equilibrium stellar systems. Here I provide a very short overview of the method and its…

Astrophysics of Galaxies · Physics 2015-05-19 Julio Chanamé

Previous work has related the Galactic bar to structure in the local stellar velocity distribution. Here we show that the bar also influences the spatial gradients of the velocity vector via the Oort constants. By numerical integration of…

Astrophysics of Galaxies · Physics 2010-02-10 Ivan Minchev , Jason Nordhaus , Alice Quillen

We present an analytic model of the stellar mass distribution of the Milky Way bar. The model is obtained by fitting a multi-component parametric density distribution to a made-to-measure N-body model of Portail et al., constructed to match…

Astrophysics of Galaxies · Physics 2022-05-25 Mattia C. Sormani , Ortwin Gerhard , Matthieu Portail , Eugene Vasiliev , Jonathan Clarke

We describe an experiment to measure the mass of the Milky Way galaxy. The experiment is based on calculated light travel times along orthogonal directions in the Schwarzschild metric of the Galactic center. We show that the difference is…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Munawar Karim , Angelo Tartaglia , Ashfaque H. Bokhari

The Milky Way (MW) hosts a central bar whose pattern speed, orientation, and length remain uncertain, largely due to observational biases and selection effects, despite the transformative data provided by the Gaia mission. We aim to…

Gas morphology and kinematics in the Milky Way contain key information for understanding the formation and evolution of our Galaxy. We present a high resolution hydrodynamical simulation based on a realistic barred Milky Way potential…

Astrophysics of Galaxies · Physics 2022-02-02 Zhi Li , Juntai Shen , Ortwin Gerhard , Jonathan P. Clarke

We present an axisymmetric, equilibrium model for late-type galaxies which consists of an exponential disk, a Sersic bulge, and a cuspy dark halo. The model is specified by a phase space distribution function which, in turn, depends on the…

Astrophysics · Physics 2010-04-21 Lawrence M. Widrow , Brent Pym , John Dubinski

The Milky Way has a barred bulge. This article summarizes the current understanding of the main structural parameters and pattern speed of the bar, and compares predicted values for the microlensing optical depth with the bulge microlensing…

Astrophysics · Physics 2008-11-26 Ortwin Gerhard

We review the Schwarzschild orbit-superposition approach and present a new implementation of this method, which can deal with a large class of systems, including rotating barred disk galaxies. We discuss two conceptuals problems in this…

Astrophysics of Galaxies · Physics 2020-05-20 Eugene Vasiliev , Monica Valluri

We have derived absolute proper motions of the entire Galactic bulge region from VIRAC and Gaia. We present these as both integrated on-sky maps and, after isolating standard candle red clump (RC) stars, as a function of distance using RC…

Astrophysics of Galaxies · Physics 2019-12-06 Jonathan P. Clarke , Christopher Wegg , Ortwin Gerhard , Leigh C. Smith , Phil W. Lucas , Shola M. Wylie

We present an implementation of the Schwarzschild orbit superposition method which can be used for constructing self-consistent equilibrium models of barred or non-barred disc galaxies, or of elliptical galaxies with figure rotation. This…

Astrophysics of Galaxies · Physics 2015-05-14 Eugene Vasiliev , E. Athanassoula

We compute a microlensing map for the Galactic bar. The predicted event rate and event duration distribution are consistent with the $55$ events recently reported by the MACHO and OGLE collaborations. Most of the events are due to lensing…

Astrophysics · Physics 2015-06-24 HongSheng Zhao , R. M. Rich , D. N. Spergel

The distance to the Galactic center $R_0$ is a fundamental parameter for understanding the Milky Way, because all observations of our Galaxy are made from our heliocentric reference point. The uncertainty in $R_0$ limits our knowledge of…

Astrophysics of Galaxies · Physics 2022-12-14 Henry W. Leung , Jo Bovy , J. Ted Mackereth , Jason A. S. Hunt , Richard R. Lane , John C. Wilson

This paper presents an equilibrium model of a Milky Way-like spiral galaxy that supports open, mostly 2- and 3-arm spiral patterns but does not form a bar. It is suggested as a more realistic alternative model to that employed by the Agora…

Astrophysics of Galaxies · Physics 2025-11-05 J A Sellwood

We use low-amplitude, long period variable (LA-LPV) candidates in \textit{Gaia} DR3 to trace the kinematics and dynamics of the Milky Way bar. LA-LPVs, like other LPVs, are intrinsically bright and follow a tight period-luminosity relation,…

Astrophysics of Galaxies · Physics 2024-12-20 Hanyuan Zhang , Vasily Belokurov , N. Wyn Evans , Sarah G. Kane , Jason L. Sanders

Non-axisymmetries in the Galactic potential (spiral arms and bar) induce kinematic groups such as the Hercules stream. Assuming that Hercules is caused by the effects of the Outer Lindblad Resonance of the Galactic bar, we model…

We discuss the results of the first model of the gas dynamics in the Milky Way in the presence of two bars: the large scale primary bar or boxy bulge and a secondary bar in the Galactic center region. We have obtained an accurate potential…

Astrophysics of Galaxies · Physics 2009-01-21 N. J. Rodriguez-Fernandez

We present a simple method for fitting parametrized mass models of the Milky Way to observational constraints. We take a Bayesian approach which allows us to take into account input from photometric and kinematic data, and expectations from…

Astrophysics of Galaxies · Physics 2015-05-27 Paul J. McMillan