Fundamental Parameters of the Milky Way Galaxy Based on VLBI Astrometry

By M. Honma, T. Nagayama, K. Ando, T. Bushimata, Y. Choi, T. Handa, T. Hirota, H. Imai, T. Jike, Mi Kyoung Kim and 24 more. 2012

157 citations recorded by the source corpus.

We present analyses to determine the fundamental parameters of the Galaxy based on VLBI astrometry of 52 Galactic maser sources obtained with VERA, VLBA, and EVN. We model the Galaxy’s structure with a set of parameters, including the Galaxy center distance R0, the angular rotation velocity at the LSR Ω0, the mean peculiar motion of the sources with respect to Galactic rotation (Usrc, Vsrc, Wsrc), the rotation-curve shape index, and the V component of the Solar peculiar motions, Vˇ. Based on a Markov chain Monte-Carlo method, we find that the Galaxy center distance is constrained at a 5% level to be R0 = 8.05 ˙ 0.45 kpc, where the error bar includes both statistical and systematic errors. We also find that the two components of the source peculiar motion Usrc and Wsrc are fairly small compared to the Galactic rotation velocity, being Usrc = 1.0 ˙ 1.5 km s � 1 and Wsrc = � 1.4 ˙ 1.2 km s � 1 . Also, the rotation curve shape is found to be basically flat between Galacto-centric radii of 4 and 13 kpc. On the other hand,

Subfields: Astronomy and Astrophysics

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In Astronomy and Astrophysics

1. M. J. Reid
2. M. Honma
3. O. Gerhard
4. L. Hou
5. Jin Han
6. Joss Bland-Hawthorn
7. P. McMillan
8. T. Dame

Citations in the corpus

• The Galaxy in Context: Structural, Kinematic, and Integrated Properties (2016, methodology): “VLBI astrometry has provided accurate parallaxes and PMs for over 100 OH, SiO, and methanol masers in high-mass star-formation regions (HMSFRs) in the Galactic disk (Honma et al. 2007, 2012; Reid et al. 2009a, 2014; Sato et al. 2010).”
• Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc (2019, background): “– Fig 14 displays the locations of nearby masers from Reid et al. (2014), Xu et al. (2016) and Honma et al. (2012) that possess parallax distances and are located within 50 pc from the Plane.”
• Molecular Clouds in the Milky Way (2015, methodology): “…(BeSSeL) Very Long Baseline Array (VLBA) survey of water and methanol masers in high-mass star-forming regions throughout the Galaxy and a similar effort with the Japanese VLBI (very long baseline interferometry) Exploration of Radio Astrometry (VERA) array (Honma et al. 2012, Reid et al. 2014).”
• The observed spiral structure of the Milky Way (2014, methodology): “At present, the most reliable measur - ments come from the trigonometric parallax observations (e.g., Xu et al. 2006; Honma et al. 2012; Reid et al. 2014) and the photometric method (e.g., Russeil et al. 2007; Foster & Brunt 2014).”
• TRIGONOMETRIC PARALLAXES OF HIGH MASS STAR FORMING REGIONS: THE STRUCTURE AND KINEMATICS OF THE MILKY WAY (2014, methodology): “…issues associated with resolving the near/far distance ambiguities for sources in the first and fourth Galactic quadrants, we used the more conservative “velocity-only” fitting as done, for example, by others (Bovy et al. 2009; McMillan & Binney 2010; Bobylev & Bajkova 2010; Honma et al. 2012).”
• Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky Way (2019, background): “Reid et al. (2009b, 2014) and Honma et al. (2012) have summarized VLBI parallaxes available at the time.”
• Rotation Curve and Mass Distribution in the Galactic Center - From Black Hole to Entire Galaxy (2013, methodology): “The rotation curve from the inner disk to the dark halo and their mass distributions have been obtained with significant accuracy (Sofue et al 2009; Sofue 2012; Honma et al. 2012; and the literature therein).”
• The third realization of the International Celestial Reference Frame by very long baseline interferometry (2020, methodology): “Additional estimates can be inferred from measurements of parallax and proper motions of Galactic masers using VLBI phasereferenced techniques (Reid et al. 2009, 2014; Brunthaler et al. 2011; Honma et al. 2012).”
• Microarcsecond Radio Astrometry (2013, methodology): “Over 100 distances to high-mass star forming regions have been measured using the astronomical “gold standard” technique of trigonometric parallax (see Reid et al. (2009b); Honma et al. (2012); Reid et al. (2014) and references therein).”
• FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) I: Project Overview and Initial Results (2017, methodology): “…mainly due to the difference of the distance of the clouds, namely the latter is likely to be more distant than the relatively local emission in the 0-10 km s−1 interval, which can be estimated using kinematic distance derived from the Galactic rotation curve (Honma et al. 2012; Reid et al. 2014).”