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Related papers: A Plausible Galactic Spiral Pattern and its Rotati…

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The position of the Sun inside the Milky Way's disc hampers the study of the spiral arm structure. We aim to analyse the spiral arms along the line-of-sight towards the Galactic centre (GC) to determine their distance, extinction, and…

Astrophysics of Galaxies · Physics 2021-09-08 Francisco Nogueras-Lara , Rainer Schödel , Nadine Neumayer

We applied the currently most comprehensive version of the statistical-parallax technique to derive kinematical parameters of the maser sample with 136 sources. Our kinematic model comprises the overall rotation of the Galactic disk and the…

Astrophysics of Galaxies · Physics 2017-06-21 A. S. Rastorguev , N. D. Utkin , M. V. Zabolotskikh , A. K. Dambis , A. T. Bajkova , V. V. Bobylev

We estimate the mass of the inner ($<20$ kpc) Milky Way and the axis ratio of its dark matter halo using globular clusters as tracers. At the same time, we constrain the phase-space distribution of the globular cluster system. We use the…

Astrophysics of Galaxies · Physics 2019-01-09 Lorenzo Posti , Amina Helmi

Using the RAVE survey, we recently brought to light a gradient in the mean galactocentric radial velocity of stars in the extended solar neighbourhood. This gradient likely originates from non-axisymmetric perturbations of the potential,…

In this work, we derive a spatially resolved map of the line-of-sight velocity of the interstellar medium and use it, along with a second map of line-of-sight velocity from Paper I of this series, to determine the nature of gaseous spiral…

Astrophysics of Galaxies · Physics 2018-11-14 Kirill Tchernyshyov , J. E. G. Peek , Gail Zasowski

The parameters of an axisymmetric model for the gravitational potential of the Galaxy have been refined. The basic curve of the Galaxy's rotation in a distance interval of $R:0-190$ kpc was constructed using the velocities of masers,…

Astrophysics of Galaxies · Physics 2026-01-14 V. V. Bobylev , A. T. Bajkova , A. A. Smirnov

Using realistic cosmological simulations of Milky Way sized haloes, we study their dynamical state and the accuracy of inferring their mass profiles with steady-state models of dynamical tracers. We use a new method that describes the…

Astrophysics of Galaxies · Physics 2016-01-13 Jiaxin Han , Wenting Wang , Shaun Cole , Carlos S. Frenk

Predictions from a Galactic Structure and Kinematic model are compared to the absolute proper-motions of about 30,000 randomly selected stars with $9 < B_{\rm J} \le 19$ derived from the Southern Proper-Motion Program (SPM) toward the South…

We determine the influence of the Milky Way's warp on the kinematics of stars across the disc, and therefore measure its precession rate and line of nodes under different assumptions. We do this by applying Jeans' first equation to a model…

Astrophysics of Galaxies · Physics 2024-07-31 Viktor Hrannar Jónsson , Paul J. McMillan

Starting from an axisymmetric equilibrium distribution function (DF) in action space, representing a Milky Way thin disc stellar population, we use the linearized Boltzmann equation to explicitly compute the response to a three-dimensional…

Astrophysics of Galaxies · Physics 2016-06-23 Giacomo Monari , Benoit Famaey , Arnaud Siebert

We analyzed the regularity/chaoticity of the orbits of 45 globular clusters in the central region of the Galaxy with a radius of 3.5 kpc, which are subject to the greatest influence from an elongated rotating bar. Various analysis methods…

Astrophysics of Galaxies · Physics 2024-06-25 Anisa Bajkova , Anton Smirnov , Vadim Bobylev

Context: The Milky Way's history of recent disturbances is vividly demonstrated by a structure in the vertical phase-space distribution known as the Gaia phase spiral. A one-armed phase spiral has been seen widely across the Milky Way disc,…

Astrophysics of Galaxies · Physics 2024-10-02 Simon Alinder , Paul McMillan , Thomas Bensby

We present evidence for a ring of stars in the plane of the Milky Way, extending at least from l = 180 deg to l = 227 deg with turnoff magnitude $g \sim 19.5$; the ring could encircle the Galaxy. We infer that the low Galactic latitude…

We built models for low bulge mass spiral galaxies (late type as defined by the Hubble classification) using a 3-D self-gravitating model for spiral arms, and analyzed the orbital dynamics as a function of pitch angle, going from 10$\deg$…

Astrophysics of Galaxies · Physics 2015-06-03 Angeles Perez-Villegas , Barbara Pichardo , Edmundo Moreno , Antonio Peimbert , Hector M. Velazquez

Using the cross-matched data of Gaia EDR3 and the 2MASS Point Source Catalog, a sample of RC stars with parallax accuracies better than 20% is identified and used to reveal the nearby spiral pattern traced by old stars. As shown in the…

Astrophysics of Galaxies · Physics 2022-06-01 Zehao Lin , Ye Xu , Ligang Hou , Dejian Liu , Yingjie Li , Chaojie Hao , Jingjing Li , Shuaibo Bian

Context. The physical processes driving the formation of Galactic spiral arms are still under debate. Studies using open clusters favour the description of the Milky Way spiral arms as long-lived structures following the classical density…

One of the scenarios for the formation of grand-design spiral arms in disky galaxies involves their interactions with a satellite or another galaxy. Here we consider another possibility, where the perturbation is instead due to the…

Astrophysics of Galaxies · Physics 2016-12-28 Marcin Semczuk , Ewa L. Lokas , Andres del Pino

The pattern speeds of spiral galaxies are closely related to the flow of material in their disks. Flows that follow the `precessing ellipses' paradigm (see e.g., Kalnajs 1973) are likely associated with slowly rotating spirals, which have…

Astrophysics of Galaxies · Physics 2010-02-08 P. A. Patsis , C. Kalapotharakos

Here we present a kinematic study of the Galactic halo out to a radius of $\sim$ 60 kpc, using 4664 blue horizontal branch (BHB) stars selected from the SDSS/SEGUE survey, to determine key dynamical properties. Using a maximum likelihood…

Astrophysics of Galaxies · Physics 2012-12-04 Prajwal R. Kafle , Sanjib Sharma , Geraint F. Lewis , Joss Bland-Hawthorn

We introduce a new methodology to robustly determine the mass profile, as well as the overall distribution, of Local Group satellite galaxies. Specifically we employ a statistical multilevel modelling technique, Bayesian hierarchical…

Astrophysics of Galaxies · Physics 2015-06-23 Gregory D. Martinez