THE ORIGIN OF LARGE PECULIAR MOTIONS OF STAR-FORMING REGIONS AND SPIRAL STRUCTURES OF OUR GALAXY

被引：85

作者：

Baba, Junichi ^{[1
]}

Asaki, Yoshiharu ^{[2
,3
]}

Makino, Junichiro ^{[1
,4
,5
]}

Miyoshi, Makoto ^{[6
]}

Saitoh, Takayuki R. ^{[1
]}

Wada, Keiichi ^{[1
,4
,5
]}

机构：

[1] Natl Inst Nat Sci, Natl Astron Observ Japan, Div Theoret Astron, Mitaka, Tokyo 1818588, Japan

[2] Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan

[3] Grad Univ Adv Studies SOKENDAI, Sch Phys Sci, Dept Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan

[4] Grad Univ Adv Studies SOKENDAI, Sch Phys Sci, Dept Astron Sci, Mitaka, Tokyo 1818588, Japan

[5] Natl Inst Nat Sci, Natl Astron Observ Japan, Ctr Computat Astrophys, Mitaka, Tokyo 1818588, Japan

[6] Natl Inst Nat Sci, Natl Astron Observ Japan, Div Radio Astron, Mitaka, Tokyo 1818588, Japan

来源：

ASTROPHYSICAL JOURNAL | 2009年 / 706卷 / 01期

基金：

日本学术振兴会;

关键词：

galaxies: kinematics and dynamics; galaxies: spiral; galaxies: structure; Galaxy: kinematics and dynamics; Galaxy: structure; ISM: kinematics and dynamics; ISM: structure; masers; methods: numerical; MILKY-WAY-GALAXY; TRIGONOMETRIC PARALLAXES; INTERSTELLAR-MEDIUM; 3-DIMENSIONAL DISTRIBUTION; DISK GALAXIES; 1ST-PRINCIPLE SIMULATIONS; MOLECULAR GAS; DISTANCE; VERA; STABILITY;

D O I：

10.1088/0004-637X/706/1/471

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Recent Very Long Baseline Interferometer (VLBI) observations determined the distances and proper motions of star-forming regions in spiral arms directly. They showed that star-forming regions and young stars have large peculiar motions as large as 30 km s(-1) with complex structures. Such a large peculiar motion is incompatible with the prediction of the standard theory of quasi-stationary spiral arms. We use a high-resolution, self-consistent N-body+hydrodynamical simulation to explore how the spiral arms are formed and maintained, and how star-forming regions move. We found that arms are not quasi-stationary but transient and recurrent, as suggested in alternative theories of spiral structures. Because of this transient nature of the spiral arms, star-forming regions exhibit a trend of large and complex non-circular motions, which is qualitatively consistent with the VLBI observations. Owing to this large non-circular motion, a kinematically estimated gas map of our Galaxy has large systematic errors of similar to 2-3 kpc in the distance from the Sun.

引用

页码：471 / 481

页数：11

共 70 条

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