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相关论文: Spiral structure in the outer Galactic disk. I. Th…

200 篇论文

We present a new face-on map of dense neutral atomic hydrogen (HI) gas in the outer Galaxy. Our map has been produced from the Leiden/Argentine/Bonn (LAB) HI 21-cm line all-sky survey by finding intensity maxima along every line of sight…

星系天体物理 · 物理学 2017-08-02 Bon-Chul Koo , Geumsook Park , Woong-Tae Kim , Myung Gyoon Lee , Dana S. Balser , Trey V. Wenger

In the third Galactic quadrant (180 < l < 270) of the Milky Way, the Galactic thin disk exhibits a significant warp ---shown both by gas and young stars--- bending down a few kpc below the formal Galactic plane (b=0). This warp shows its…

星系天体物理 · 物理学 2015-06-22 Giovanni Carraro , Ruben A. Vazquez , Edgardo Costa , Javier A. Ahumada , Edgar E. Giorgi

We present a map of the spiral structure of the Galaxy, as traced by molecular CS emission associated with IRAS sources which are believed to be compact HII regions. The CS line velocities are used to determine the kinematic distances of…

星系天体物理 · 物理学 2015-05-20 J. R. D. Lepine , A. Roman-Lopes , Zulema Abraham , T. C. Junqueira , Yu. N. Mishurov

The Outer Scutum-Centaurus arm (OSC) is the most distant molecular spiral arm known in the Milky Way. The OSC may be the very distant end of the well-known Scutum-Centaurus arm, which stretches from the end of the Galactic bar to the outer…

Spiral arms shown by different components may not be spatially coincident, which can constrain formation mechanisms of spiral structure in a galaxy. We reassess the spiral arm tangency directions in the Milky Way through identifying the…

星系天体物理 · 物理学 2015-09-30 L. G. Hou , J. L. Han

Using data from the Southern Galactic Plane Survey we present a possible distant spiral arm in the fourth quadrant of the Milky Way. The very distinct and cohesive feature can be traced for over 70 deg as the most extreme positive velocity…

天体物理学 · 物理学 2009-11-10 N. M. McClure-Griffiths , J. M. Dickey , B. M. Gaensler , A. J. Green

We investigate the morphology and kinematics of the Galactic spiral structure based on a new sample of O- and early B-type stars. We select 6,858 highly confident OB star candidates from the combined data of the VST Photometric H$\alpha$…

星系天体物理 · 物理学 2019-06-11 Chen Bingqiu , Huang Yang , Hou Ligang , Tian Hao , Li Guangxing , Yuan Haibo , Wang Haifeng , Wang Chun , Tian Zhijia , Liu Xiaowei

We aim to explore the actions of the new Gaia DR3 astrometry to find structures in the Galactic disc. We compute the actions and the orbital parameters of the Gaia DR3 stars with full astrometry and velocities assuming an axisymmetric model…

星系天体物理 · 物理学 2023-02-01 P. A. Palicio , A. Recio-Blanco , E. Poggio , T. Antoja , P. J. McMillan , E. Spitoni

In this contribution we summarize recent achievements by our group on the understanding of the structure of the outer Galactic disk, with particular emphasis to the outer disk extent, and the spiral structure beyond the solar circle.

星系天体物理 · 物理学 2013-10-08 G. Carraro , G. Perren , R. A. Vázquez , A. Moitinho

The spiral structure of the Milky Way is not conclusive, even for the disc regions in the solar neighbourhood. Especially, the arm-like structures uncovered from the over-density maps of evolved stars are inconsistent with the commonly…

星系天体物理 · 物理学 2025-04-09 X. J. Shen , L. G. Hou , H. L. Liu , X. Y. Gao

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…

星系天体物理 · 物理学 2015-06-17 Vadim V. Bobylev , Anisa 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…

天体物理学 · 物理学 2015-06-24 Hiroyuki Nakanishi , Yoshiaki Sofue

The spiral structure of the Milky Way is not yet well determined. The keys to understanding this structure are to increase the number of reliable spiral tracers and to determine their distances as accurately as possible. HII regions, giant…

星系天体物理 · 物理学 2014-10-15 L. G. Hou , J. L. Han

The observed gas dynamics in the Milky Way can only be explained by a bar in the galactic center. Such a bar is directly visible in the near-IR maps of the bulge, where it causes a distinctive asymmetric light distribution pattern. Another…

天体物理学 · 物理学 2007-05-23 Peter Englmaier

Knowledge about the distribution of CO emission in the Milky Way is essential to understand the impact of Galactic environment on the formation and evolution of structures in the interstellar medium. However, currently our insight about the…

星系天体物理 · 物理学 2020-08-19 M. Riener , J. Kainulainen , J. D. Henshaw , H. Beuther

This study extends to the structure of the Galaxy. Our main goal is to focus on the first spiral arm beyond the Perseus arm, often called the Cygnus arm or the Outer Norma arm, by appraising the distributions of the masers near the Cygnus…

星系天体物理 · 物理学 2020-04-15 Jacques P Vallée

Context. The astrometric satellite Gaia is expected to significantly increase our knowledge as to the properties of the Milky Way. The Gaia Early Data Release 3 (Gaia EDR3) provides the most precise parallaxes for many OB stars, which can…

星系天体物理 · 物理学 2021-01-20 Y. Xu , L. G. Hou , S. B. Bian , C. J. Hao , D. J. Liu , J. J. Li , Y. J. Li

We examine the outer Galactic HI disk for deviations from the b=0 plane by constructing maps of disk surface density, mean height, and thickness. We find that the Galactic warp is well described by a vertical offset plus two Fourier modes…

天体物理学 · 物理学 2007-05-23 E. S. Levine , Leo Blitz , Carl Heiles , Martin Weinberg

An up-to-date overview of the recent history is given, aiming to present a helpful working guide to the literature and at the same time introduce key systems and observational results, starting from the Sun and going towards the Galactic…

星系天体物理 · 物理学 2017-11-28 Jacques P Vallee

We present a new catalogue of spectrophotometric distances and line-of-sight systemic velocities to 103 HII regions between 90$^{\circ}\leq \ell \leq~$195$^{\circ}$ (longitude quadrants II and part of III). Two new velocities for each…

星系天体物理 · 物理学 2015-10-21 Tyler J. Foster , Christopher M. Brunt