BeSSeL Survey

Proper motions of Local Group galaxies.
The structure of the Milky Way: The BeSSeL Survey
The Galactic Center: Sgr A*
Supernova 2008iz in M82
Extragalactic H2O Masers: Local Group, 3C 403, MG J0414+0534
Circular Polarization in AGN: M81
Jets in AGN: The case of III Zw 2
VLBI Astrometry and Phase-referencing.

The BeSSeL Survey (Bar and Spiral Structure Legacy Survey) is a VLBA Key Science project to study the spiral structure and kinematics of the Milky Way. The Survey is named in honor of Friedrich Willhelm Bessel who measured the first stellar parallax in 1838. We will accomplish this by determining distances, via trigonometric parallax, and proper motions of star forming regions in the Milky Way.

The target sources are methanol and water masers that are associated with young massive stars and compact HII regions that trace spiral structure. With accurate distance measurements we will locate spiral arms, and with absolute proper motions we can determine the 3-dimensional motions of these massive young stars.

Over the past decade, we have developed and tested the techniques needed to achieve better than 0.03 mas relative positional accuracy between maser sources and background QSOs at each epoch. Before beginning this project, we determined trigonometric parallaxes to 11 star forming regions with accuracies of order 0.01 mas. We also measured absolute proper motions with accuracies of order 1 km/s. These results have been published in a series of papers in the Astrophyscial Journal in 2009.

See NRAO or CfA press releases

Milky Way (Illustration Credit: Robert Hurt, IPAC; Mark Reid, CfA, NRAO/AUI/NSF)

Project Team

Mark Reid & Tom Dame: Harvard-Smithsonian Center for Astrophysics, USA
Karl Menten, Andreas Brunthaler & Yoon Kyung Choi: Max-Planck-Institut für Radioastronomie, Germany
Xu Ye: Purple Mountain Observatory, China
Zheng Xing-Wu & Zhang Bo: Nanjing University, China
Luca Moscadelli & Alberto Sanna: Arcetri Observatory, Italy
George Moellenbrock, NRAO, USA
Mayumi Sato, Tokyo University, Japan
Anna Bartkiewicz: Torun Observatory, Poland
Kazuya Hachisuka: Shanghai Observatory, China

Published in:

Hachisuka K., Brunthaler A., Menten K.M., Reid M.J., Imai H., Hagiwara Y., Miyoshi M., Horiuchi S., Sasao T., 2006, ApJ 645, 337
Bartkiewicz A., Brunthaler A., Szymczak M., van Langevelde H.J., Reid M.J., 2008, A&A 490, 787
Reid M.J., Menten K.M., Brunthaler A., Zheng X.W., Moscadelli L., Xu Y., 2009, ApJ 693, 397
Moscadelli L., Reid M.J., Menten K.M., Brunthaler A., Zheng X.W., Xu Y., 2009, ApJ 693, 406
Xu Y., Reid M.J., Menten K.M., Brunthaler A., Zheng X.W., Moscadelli L., 2009, ApJ 693, 413
Zhang B., Zheng X.W., Reid M.J., Menten K.M., Xu Y., Moscadelli L., Brunthaler A., 2009, ApJ 693, 419
Brunthaler A., Reid M.J., Menten K.M., Zheng X.W., Moscadelli L., Xu Y., 2009, ApJ 693, 424
Reid M.J., Menten K.M., Zheng X.W., Brunthaler A. et al. 2009, ApJ 700, 137
Hachisuka K., Brunthaler A., Menten K.M., Reid M.J., Hagiwara Y., Mochizuki N., 2009, ApJ 696, 1981
M.J. Reid, K.M. Menten, X.W. Zheng, A. Brunthaler, Y. Xu, 2009, ApJ 705, 1548
Sanna A., Reid M.J., Moscadelli L., Dame T.M., Menten K.M., Brunthaler A., Zheng X.W., Xu Y. 2009, ApJ 706, 464
Rygl K.L.J, Brunthaler A., Menten K.M., Reid M.J., van Langevelde H.J., Xu Y., 2010, A&A 511, A2

Last modified: 23-February-2010