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Related papers: A New Method for Determining the Milky Way Bar Pat…

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We present a proper motion mini-survey of 35 fields in the vicinity of Baade window, (l, b) = (1 deg, -4 deg), sampling roughly a 5 x 2.5 deg region of the Galactic bar. Our second epoch observations collected with the ACS/HRC instrument on…

Astrophysics · Physics 2009-11-11 S. Kozlowski , P. R. Wozniak , S. Mao , M. C. Smith , T. Sumi , W. T. Vestrand , L. Wyrzykowski

Models of the Galaxy with analytical Ferrers bars can reproduce the residual velocities of OB-associations in the Sagittarius, Perseus and Local System stellar-gas complexes located within 3 kpc solar neighborhood. Ferrers ellipsoids with…

Astrophysics of Galaxies · Physics 2019-02-12 Anna M. Melnik

We use Fabry-Perot absorption line imaging spectroscopy to measure radial velocities using the Ca II 8542 line in 3360 stars towards three lines of sight in the Milky Way's bar: Baade's Window and offset position at (l,b) ~ (+-5.0, -3.5).…

Astrophysics · Physics 2011-02-11 Naseem Rangwala , T. B. Williams , K. Z. Stanek

The tumbling pattern of a bar is the main parameter characterising its dynamics. From numerical simulations, its evolution since bar formation is tightly linked to the dark halo in which the bar is formed through dynamical friction and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 I. Perez , J. A. L. Aguerri , J. Mendez-Abreu

Galaxy models have long predicted that galactic bars slow down by losing angular momentum to their postulated dark haloes. When the bar slows down, resonance sweeps radially outwards through the galactic disc while growing in volume,…

Astrophysics of Galaxies · Physics 2023-08-04 Rimpei Chiba , Ralph Schönrich

In this paper we develop a calculation code to account for the effects carried by fast rotation on the observed spectra of early-type stars. Stars are assumed to be in rigid rotation and the grid of plane-parallel model atmospheres used to…

Astrophysics · Physics 2007-05-23 Y. Fremat , J. Zorec , A. -M. Hubert , M. Floquet

We use an $N$-body+smoothed particle hydrodynamics simulation of an isolated barred galaxy to study the age dependence of bulge longitudinal proper motion ($\mu_l$) rotation curves. We show that close to the minor axis ($|l| \sim 0^\circ$)…

We have tested the method of determining the solar Galactocentric distance R_0 and Galactic rotation velocity $V_0$ modified by Sofue et al. using near-solar-circle objects. The motion of objects relative to the local standard of rest has…

Astrophysics of Galaxies · Physics 2013-01-01 V. V. Bobylev

We characterize empirically the radial diffusion of stars in the plane of a typical barred disk galaxy by calculating the local spatial diffusion coefficient and diffusion time-scale for bulge-disk-halo N-body self-consistent systems which…

Astrophysics of Galaxies · Physics 2015-05-30 Maura Brunetti , Cristina Chiappini , Daniel Pfenniger

We consider the model involving the oscillation of the effective gravitational constant that has been put forward in an attempt to reconcile the observed periodicity in the galaxy number distribution with the standard cosmological models.…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Marcelo Salgado , Daniel Sudarsky , Hernando Quevedo

We investigate the relations between the properties of bars and their host galaxies in a sample of 77 nearby barred galaxies, spanning a wide range of morphological types and luminosities, with 34 SB0-SBa and 43 SBab-SBc galaxies. The…

Astrophysics of Galaxies · Physics 2020-09-23 Virginia Cuomo , J. Alfonso L. Aguerri , Enrico Maria Corsini , Victor P. Debattista

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

An accurate knowledge of the dark matter distribution in the Milky Way is of crucial importance for galaxy formation studies and current searches for particle dark matter. In this paper we set new dynamical constraints on the Galactic dark…

Astrophysics of Galaxies · Physics 2015-12-03 Miguel Pato , Fabio Iocco , Gianfranco Bertone

With the steady increase of the sample size of observed microlenses towards the central regions of the Galaxy, the main source of the uncertainty in the lens mass will shift from the simple Poisson noise to the intrinsic non-uniqueness of…

Astrophysics · Physics 2009-10-30 HongSheng Zhao , P. Tim de Zeeuw

The effects of the Galactic bar on the velocity distribution of old disc stars in the Solar neighbourhood are investigated using high-resolution 2D test particle simulations. A detailed orbital analysis reveals that the structure of the U-V…

Astrophysics · Physics 2007-05-23 R. Fux

We report on an estimate of the bar pattern speed Omega_p for the low surface brightness spiral galaxy UGC 628. We applied the Tremaine-Weinberg method to high resolution Halpha velocity and integrated emission maps of this dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-11 Laurent Chemin , Olivier Hernandez

Context: The Large Magellanic Cloud (LMC) internal kinematics have been studied in unprecedented depth thanks to the excellent quality of the Gaia mission data, revealing the disc's non-axisymmetric structure. Aims: We want to constrain the…

Context: Using Gaia DR3 data, Jim\'enez-Arranz et al. (2024a) computed the LMC bar pattern speed using three different methods. One of them suggested that the LMC might be hosting a bar that barely rotates, and is slightly counter-rotating…

Astrophysics of Galaxies · Physics 2025-05-28 Óscar Jiménez-Arranz , Santi Roca-Fàbrega

We make use of recent estimates for the parameters of the Milky Way's halo globular clusters and study the influence of the galactic bar on the dynamics of these clusters by computing their orbits. We use both an axisymmetric and…

Astrophysics of Galaxies · Physics 2023-03-13 Roman Tkachenko , Vladimir Korchagin , Anna Jmailova , Giovanni Carraro , Boris Jmailov

We propose a method for measuring the cosmological density parameter $\Omega$ from the statistics of the divergence field, $\theta \equiv H^{-1} \div v$, the divergence of peculiar velocity, expressed in units of the Hubble constant, $H…

Astrophysics · Physics 2015-06-24 F. Bernardeau , R. Juszkiewicz , A. Dekel , F. R. bouchet