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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: kazunori.akiyama@nao.ac.jp 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 

References

Akiyama, K., Takahashi, R., Honma, M., Oyama, T., & Kobayashi, H. 2013, PASJ 65, 91Google Scholar
Bower, G. C., Falcke, H., Herrnstein, R. M., et al. 2004, Science, 304, 704Google Scholar
Broderick, A. E. & Loeb, A. 2006, MNRAS 367, 905CrossRefGoogle Scholar
Gillessen, S., Eisenhauer, F., Fritz, T. K., et al. 2009, ApJ Lett. 707, L114Google Scholar
Gillessen, , et al. 2012, Nature 481, 51Google Scholar
Gillessen, S., Genzel, R., Fritz, T. K., et al. 2013, ApJ 774, 44Google Scholar
Falcke, , & Biermann, 1995, A&A 293, 665Google Scholar
Falcke, H., Markoff, S., & Bower, G. C. 2009, A&A 496, 77Google Scholar
Herrnstein, R. M., Zhao, J.-H., Bower, G. C., & Goss, W. M. 2004, AJ 127, 3399CrossRefGoogle Scholar
Honma, M., Nagayama, T., Ando, K., et al. 2012, PASJ 64, 136Google Scholar
Lee, S.-S., Byun, D.-Y., Oh, C. S., et al. 2011, PASP 123, 1398Google Scholar
Lu, R.-S., Krichbaum, T. P., Eckart, A., König, , et al. 2011, A&A 525, A76Google Scholar
Lo, K. Y., Shen, Z.-Q., Zhao, J.-H., & Ho, P. T. P. 1998, ApJ Lett. 508, L61Google Scholar
Loeb, A. & Waxman, E. 2007, JCAP 3, 11Google Scholar
Mahadevan, , 1997, ApJ 477, 585Google Scholar
Mościbrodzka, , et al. 2012, ApJ Lett. 752, L1Google Scholar
Narayan, , Özel, & Sironi, 2012, ApJ Lett. 757, L20CrossRefGoogle Scholar
Phifer, K., Do, T., Meyer, L., et al. 2013, ApJ Lett. 773, L13CrossRefGoogle Scholar
Rickett, B. J. 1990, ARAA 28, 561CrossRefGoogle Scholar
Yusef-Zadeh, F., Roberts, D., Wardle, M., Heinke, C. O., & Bower, G. C. 2006, ApJ 650, 189Google Scholar