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Long-term monitoring of Sgr A* at 7 mm with VERA and KaVA

Published online by Cambridge University Press:  22 May 2014

K. Akiyama ,
M. Kino ,
B. Sohn ,
S. Lee ,
S. Trippe  and
M. Honma
K. Akiyama
Affiliation:
Department of Astronomy, Graduate School of Science, The University of Tokyo, Japan email: [email protected] Mizusawa VLBI Observatory, National Astronomical Observatory of Japan
M. Kino
Affiliation:
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
B. Sohn
Affiliation:
Korea Astronomy & Space Science Institute, Korea
S. Lee
Affiliation:
Korea Astronomy & Space Science Institute, Korea
S. Trippe
Affiliation:
Department of Physics and Astronomy, Seoul National University, Korea
M. Honma
Affiliation:
Mizusawa VLBI Observatory, National Astronomical Observatory of Japan Graduate University for Advanced Studies, Japan
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Abstract

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We present the results of radio monitoring observations of Sgr A* at 7 mm (i.e. 43 GHz) with the VLBI Exploration of Radio Astrometry (VERA), which is a VLBI array in Japan. VERA provides angular resolution on millisecond scales, resolving structures within 100 Schwarzschild radii of Sgr A* , similar to the Very Large Baseline Array (VLBA). We performed multi-epoch observations of Sgr A* in 2005 - 2008, and started monitoring it again with VERA from 2013 January to trace the current G2 encounter event. Our preliminary results in 2013 show that Sgr A* on mas scales has been in an ordinary state as of August 2013, although some fraction of the G2 cloud already passed the pericenter of Sgr A* in April 2013. We will continue monitoring Sgr A* with VERA and the newly developed KaVA (KVN and VERA Array).

Keywords

Galaxy: center — Galaxies: nuclei — Individual: Sgr A* — techniques: interferometric — techniques: high angular resolution
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 9 , Symposium S303: The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus , October 2013 , pp. 288 - 292
Copyright
Copyright © International Astronomical Union 2014 

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