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Related papers: A New Model for the Milky Way Bar

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We present an update to the frequency analysis method for measuring the properties of a galactic bar. The method involves computing the fundamental frequencies of orbits in rotating, N-body-derived potential models, classifying the stars as…

Astrophysics of Galaxies · Physics 2026-05-13 Zachary Langford , Robyn Sanderson , Madeline Lucey , Jason A. S. Hunt

Recent GLIMPSE data have further confirmed the hypothesis of the existence of an in-plane long bar different from the bulge of the Milky Way with the same characteristics as emphasized some years ago by our team. In this paper, we present…

We provide a purely dynamical global map of the non-axisymmetric structure of the Milky Way disk. For this, we exploit the information contained within the in-plane motions of disk stars from Gaia DR3 to adjust a model of the Galactic…

Astrophysics of Galaxies · Physics 2025-07-16 Y. R. Khalil , B. Famaey , G. Monari , M. Bernet , A. Siebert , R. Ibata , G. F. Thomas , P. Ramos , T. Antoja , C. Li , S. Rozier , M. Romero-Gómez

We developed an orbit-superposition method for edge-on barred galaxies and evaluated its capability to recover the bar pattern speed $\rm\Omega_p$. We selected three simulated galaxies (Au-18, Au-23, and Au-28) with known pattern speeds…

Astrophysics of Galaxies · Physics 2025-08-27 Yunpeng Jin , Ling Zhu , Behzad Tahmasebzadeh , Shude Mao , Glenn van de Ven , Rui Guo , Runsheng Cai

We study the late-time evolution of the central regions of two Milky Way-like simulations of galaxies formed in a cosmological context, one hosting a fast bar and the other a slow one. We find that bar length, R_b, measurements fluctuate on…

Our recent studies of axial-symmetry breaking in the nearby ($d <3 \,{\rm kpc}$) star counts are sensitive to the distortions of stellar orbits perpendicular and parallel to the orientation of the bar just within and beyond the outer…

Astrophysics of Galaxies · Physics 2020-08-20 Austin Hinkel , Susan Gardner , Brian Yanny

We present mass models of the Milky Way created to fit observational constraints and to be consistent with expectations from theoretical modelling. The method used to create these models is that demonstrated in McMillan (2011), and we…

Astrophysics of Galaxies · Physics 2016-12-07 Paul J. McMillan

I provide a model rotation curve for the Milky Way that matches the details of the terminal velocity curve normalized to the Galactocentric distance $R_0 = 8.122$ kpc obtained by the GRAVITY collaboration and the corresponding circular…

Astrophysics of Galaxies · Physics 2018-08-29 Stacy McGaugh

The Laser Interferometer Space Antenna (LISA) will enable Galactic gravitational wave (GW) astronomy by individually resolving $ > 10^4$ signals from double white dwarf (DWD) binaries throughout the Milky Way. In this work we assess for the…

Astrophysics of Galaxies · Physics 2025-10-03 Maite J. C. Wilhelm , Valeriya Korol , Elena M. Rossi , Elena D'Onghia

Like the majority of spiral galaxies, the Milky Way contains a central non-axisymmetric bar component. Our position in the Galactic plane renders it rather hard to see, but also allows us to make measurements of the bar that are completely…

Astrophysics · Physics 2008-11-26 M. R. Merrifield

Tremendous progress has been made recently in modelling the morphology and kinematics of centers of galaxies. Increasingly realistic models are built for central bar, bulge, nucleus and black hole of galaxies, including our own. The newly…

Astrophysics · Physics 2009-10-31 HongSheng Zhao

Using $N$-body simulations we study the buckling instability in a galactic bar forming in a Milky Way-like galaxy. The galaxy is initially composed of an axisymmetric, exponential stellar disk embedded in a spherical dark matter halo. The…

Astrophysics of Galaxies · Physics 2019-09-04 Ewa L. Lokas

We use Gaia DR3 to explore how well equilibrium dynamical models based on the Jeans equations and the Schwarzschild orbit superposition method are able to describe LMC's 5-dimensional phase-space distribution and line-of-sight (LOS)…

Astrophysics of Galaxies · Physics 2024-12-04 Nikolay Kacharov , Behzad Tahmasebzadeh , Maria-Rosa L. Cioni , Glenn van de Ven , Ling Zhu , Sergey Khoperskov

We have modelled 38 barred galaxies by using near-IR and optical data from the Ohio State University Bright Spiral Galaxy Survey. We constructed the gravitational potentials of the galaxies from $H$-band photometry, assuming constant…

Astrophysics · Physics 2009-11-13 P. Rautiainen , H. Salo , E. Laurikainen

The Galactic bulge and bar are critical to our understanding of the Milky Way. However, due to the lack of reliable stellar distances, the structure and kinematics of the bulge/bar beyond the Galactic center have remained largely…

The bar pattern speed ($\Omega_{\rm b}$) is defined as the rotational frequency of the bar, and it determines the bar dynamics. Several methods have been proposed for measuring $\Omega_{\rm b}$. The non-parametric method proposed by…

Longitude-velocity (l-V) diagrams of H I and CO gas in the inner Milky Way have long been known to be inconsistent with circular motion in an axisymmetric potential. Several lines of evidence suggest that the Galaxy is barred, and gas flow…

Astrophysics · Physics 2008-11-26 Benjamin J. Weiner , J. A. Sellwood

We present a study of the luminosity density distribution of the Galactic bar using number counts of red clump giants (RCGs) from the OGLE-III survey. The data were recently published by Nataf et al. (2013) for 9019 fields towards the bulge…

Astrophysics of Galaxies · Physics 2013-09-24 Liang Cao , Shude Mao , David Nataf , Nicholas J. Rattenbury , Andrew Gould

Accurate observational data on the rotation curve of the Milky Way galaxy (MW) are very well understood using the gravitational potentials of the baryonic matter (Pouliasis et al., 2017) and the interpolating function presented by McGaugh…

Astrophysics of Galaxies · Physics 2024-07-18 Jozef Klačka , Michal Šturc , Emil Puha

We define a physically-motivated measure for galactic bar length, called the dynamical length. The dynamical length of the bar corresponds to the radial extent of the orbits that are the backbone supporting the bar feature. We propose a…

Astrophysics of Galaxies · Physics 2023-05-24 Michael S. Petersen , Martin D. Weinberg , Neal Katz