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Related papers: On the Galactic Spiral Patterns: Stellar and Gaseo…

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We present the kinematics of the molecular gas in the barred spiral galaxy M83 (NGC5236). The study is based on ^{12}CO(J=1--0 and 2--1) observations with the Swedish-ESO Submillimetre Telescope (SEST). Iso-velocity maps of the entire…

Astrophysics · Physics 2009-11-10 A. A. Lundgren , H. Olofsson , T. Wiklind , G. Rydbeck

We report the existence of spiral arms in the recently formed gaseous and dusty disk of the closest giant elliptical, NGC 5128 (Centaurus A), using high resolution 12CO(2-1) observations of the central 3 arcmin (3 kpc) obtained with the…

Astrophysics of Galaxies · Physics 2015-06-11 D. Espada , S. Matsushita , A. B. Peck , C. Henkel , F. Israel , D. Iono

We propose a new dynamical picture of galactic stellar and gas spirals, based on hydrodynamic simulations in a `live' stellar disk. We focus especially on spiral structures excited in a isolated galactic disk without a stellar bar. Using…

Astrophysics of Galaxies · Physics 2015-05-27 Keiichi Wada , Junichi Baba , Takayuki R. Saitoh

With the Plateau de Bure interferometer, we have measured the C, N, O and S isotopic abundance ratios in the arm of a spiral galaxy with a redshift of 0.89. The galaxy is seen face-on according to HST images. Its bulge intercepts the line…

Astrophysics · Physics 2009-11-11 Sebastien Muller , Michel Guelin , Michael Dumke , Robert Lucas , Francoise Combes

We present a new model for the gas dynamics in the galactic disk inside the Sun's orbit. Quasi-equilibrium flow solutions are determined in the gravitational potential of the deprojected COBE NIR bar and disk, complemented by a central cusp…

Astrophysics · Physics 2009-10-31 Peter Englmaier , Ortwin Gerhard

The rotation velocity of the spiral pattern of the Galaxy is determined by direct observation of the birthplaces of open clusters of stars in the galactic disk as a function of their age. Our measurement does not depend on any specific…

Astrophysics · Physics 2009-11-10 W. S. Dias , J. R. D. Lépine

The density wave theory predicted some physical offsets among different tracers of star formation. To test this prediction, here we compiled data on 40 galaxies searched observationally for a physical offset between spiral arm tracers, and…

Astrophysics of Galaxies · Physics 2019-11-21 Jacques P Vallee

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

We have studied a sample containing about 6000 OB stars with proper motions and trigonometric parallaxes from the Gaia DR2 catalogue. The following parameters of the angular velocity of Galactic rotation have been found:…

Astrophysics of Galaxies · Physics 2019-06-26 V. V. Bobylev , A. T. Bajkova

There are two theories of stellar spiral arms in isolated disc galaxies that model stellar spiral arms with different longevities: quasi-stationary density wave theory, which characterises spirals as rigidly rotating, long-lived patterns…

Astrophysics of Galaxies · Physics 2016-05-04 Junichi Baba , Kana Morokuma-Matsui , Yusuke Miyamoto , Fumi Egusa , Nario Kuno

The generation of spiral arms and the mechanisms controlling their properties within a realistic cosmological framework - the complete understanding is still beyond our grasp. Using a statistically significant sample of Milky Way- and…

Astrophysics of Galaxies · Physics 2025-10-31 Soumavo Ghosh , Elena D'Onghia

We present a revised method for simultaneous determination of the pattern speed and star formation timescale of spiral galaxies, its application, and results for CO and Ha images of nearby spiral galaxies. Out of 13 galaxies, we were able…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Fumi Egusa , Kotaro Kohno , Yoshiaki Sofue , Hiroyuki Nakanishi , Shinya Komugi

To study the peculiarities of the Galactic spiral density wave, we have analyzed the space velocities of Galactic Cepheids with proper motions from the Hipparcos catalog and line-of-sight velocities from various sources. First, based on the…

Astrophysics of Galaxies · Physics 2012-12-20 V. V. Bobylev , A. T. Bajkova

We created a three-dimensional distribution map of molecular gas throughout the Milky Way Galaxy using the latest $^{12}$CO($J=$1--0) survey data cube and rotation curve based on the kinematic distance. The radial distribution of the…

Astrophysics · Physics 2015-06-24 Hiroyuki Nakanishi , Yoshiaki Sofue

To estimate the parameters of the Galactic spiral structure - namely, the pitch angle i and the number of spiral arms,- data on Galactic masers with known trigonometric parallaxes were used. We applied the well-known method based on…

Astrophysics of Galaxies · Physics 2015-06-17 Vadim V. Bobylev , Anisa T. Bajkova

Identifying the structure of our Galaxy has always been fraught with difficulties, and while modern surveys continue to make progress building a map of the Milky Way, there is still much to understand. The arm and bar features are important…

Astrophysics of Galaxies · Physics 2020-01-08 Alex R. Pettitt , Sarah E. Ragan , Martin C. Smith

The kinematical features of the Sagittarius (R=5.7 kpc), Carina (R=6.5 kpc), Cygnus (R=6.8 kpc), and Perseus (R=8.2 kpc) arm fragments suggest the existence of two spiral patterns rotating at different angular velocities in the Galaxy. The…

Astrophysics · Physics 2007-05-23 A. M. Mel'nik

Star clusters provide unique advantages for investigating Galactic spiral arms, particularly due to their precise ages, positions, and kinematic properties, which are further enhanced by ongoing updates from the astrometric data. In this…

Astrophysics of Galaxies · Physics 2025-01-27 Xiaochen Liu , Zhihong He , Yangping Luo , Kun Wang

We present a suite of direct $N$-body simulations of the Hyades open cluster and its tidal stream in a Milky Way potential that includes a rotating bar and spiral arms. Using the high-resolution code PETAR and an AGAMA-based multi-component…

Astrophysics of Galaxies · Physics 2026-04-01 Zi-yi Zhou , Long Wang , Tereza Jerabkova , Zhenghao He

In this paper we introduce a new method for analysing Milky Way phase-space which allows us to reveal the imprint left by the Milky Way bar and spiral arms on the stars with full phase-space data in Gaia Data Release 2. The unprecedented…

Astrophysics of Galaxies · Physics 2020-02-05 S. Khoperskov , O. Gerhard , P. Di Matteo , M. Haywood , D. Katz , S. Khrapov , A. Khoperskov , M. Arnaboldi