Skip to main content

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
Cancel
×
×
Home
  • Home
Article

Millimeter VLBI observations of Sgr A* with KaVA and KVN

  • G.-Y. Zhao (a1), M. Kino (a1), I.-J. Cho (a1) (a2), K. Akiyama (a3) (a4), B. W. Sohn (a1) (a2), T. Jung (a1) (a2), J. C. Algaba (a1), K. Hada (a4), Y. Hagiwara (a5), J. Hodgson (a1), M. Honma (a4), N. Kawaguchi (a6), S. Koyama (a7), J. A. Lee (a1) (a2), T. Lee (a8), K. Niinuma (a9), J. Oh (a8), J.-H. Park (a8), H. Ro (a1) (a10), S. Sawada-Satoh (a11), F. Tazaki (a4), S. Trippe (a8), K. Wajima (a1) and H. Yoo (a1) (a10)...
Abstract

We present recent observation results of Sgr A* at millimeter obtained with VLBI arrays in Korea and Japan.

7 mm monitoring of Sgr A* is part of our AGN large project. The results at 7 epochs during 2013-2014, including high resolution maps, flux density and two-dimensional size measurements are presented. The source shows no significant variation in flux and structure related to the G2 encounter in 2014. According to recent MHD simulations by kawashima et al., flux and magnetic field energy can be expected to increase several years after the encounter; We will keep our monitoring in order to test this prediction.

Astrometric observations of Sgr A* were performed in 2015 at 7 and 3.5 millimeter simultaneously. Source-frequency phase referencing was applied and a combined ”core-shift” of Sgr A* and a nearby calibrator was measured. Future observations and analysis are necessary to determine the core-shift in each source.

Copyright
COPYRIGHT: © International Astronomical Union 2017 
References
Hide All
Akiyama, K., Kino, M., Sohn, B., et al. 2014, in IAU Symposium, Vol. 303, IAU Symposium, ed. Sjouwerman, L. O., Lang, C. C., & Ott, J., 288–292
Akiyama, K., Takahashi, R., Honma, M., Oyama, T., & Kobayashi, H. 2013, PASJ, 65, 91
Algaba, J.-C., Zhao, G.-Y., Lee, S.-S., et al. 2015, JKAS, 48, 237
Boehle, A., Ghez, A. M., Schödel, R., et al. 2016, arXiv:1607.05726
Bower, G. C., Deller, A., Demorest, P., et al. 2015, ApJ, 798, 120
Bower, G. C., Falcke, H., Herrnstein, R. M., et al. 2004, Science, 304, 704
Bower, G. C., Markoff, S., Brunthaler, A., et al. 2014, ApJ, 790, 1
Bower, G. C., Markoff, S., Dexter, J., et al. 2015, ApJ, 802, 69
Brinkerink, C. D., Müller, C., Falcke, H., et al. 2016, MNRAS, 462, 1382
Cho, I.-J., et al. in preparation
Falcke, H., Mannheim, K., & Biermann, P. L. 1993, A&A, 278, L1
Falcke, H. & Markoff, S. 2000, A&A, 362, 113
Falcke, H., Markoff, S., & Bower, G. C. 2009, A&A, 496, 77
Gillessen, S., Genzel, R., Fritz, T. K., et al. 2012, Nature, 481, 51
Hada, K., Doi, A., Kino, M., et al. 2011, Nature, 477, 185
Jung, T., Dodson, R., Han, S.-T., et al. 2015, Journal of Korean Astronomical Society, 48, 277
Kawashima, T., Matsumoto, Y., & Matsumoto, R. 2016, PASJ, submitted
Lee, S.-S., Oh, C. S., Roh, D.-G., et al. 2015, Journal of Korean Astronomical Society, 48, 125
Li, Z., Morris, M. R., & Baganoff, F. K. 2013, ApJ, 779, 154
Lobanov, A. P. 1998, A&A, 330, 79
Lu, R.-S., Krichbaum, T. P., Eckart, A., et al. 2011, A&A, 525, A76
Mahadevan, R. 1997, ApJ, 477, 585
Melia, F., Liu, S., & Coker, R. 2001, ApJ, 553, 146
Mościbrodzka, M., Shiokawa, H., Gammie, C. F., & Dolence, J. C. 2012, ApJ, 752, L1
Niinuma, K., Lee, S.-S., Kino, M., et al. 2014, PASJ, 66, 103
Park, J.-H., Trippe, S., Krichbaum, T. P., et al. 2015, A&A, 576, L16
Ponti, G., De Marco, B., Morris, M. R., et al. 2015, MNRAS, 454, 1525
Rioja, M. & Dodson, R. 2011, AJ, 141, 114
Rioja, M. J., Dodson, R., Jung, T., et al. 2014, AJ, 148, 84
Rioja, M. J., Dodson, R., Jung, T., & Sohn, B. W. 2015, AJ, 150, 202
Shen, Z.-Q. 2008, in American Institute of Physics Conference Series, Vol. 968, Astrophysics of Compact Objects, ed. Yuan, Y.-F., Li, X.-D., & Lai, D., 340–347
Sokolovsky, K. V., Kovalev, Y. Y., Pushkarev, A. B., & Lobanov, A. P. 2011, A&A, 532, A38
Valencia-S., M., Eckart, A., Zajaček, M., et al. 2015, ApJ, 800, 125
Yuan, F., Quataert, E., & Narayan, R. 2003, ApJ, 598, 301
Yusef-Zadeh, F., Roberts, D., Wardle, M., Heinke, C. O., & Bower, G. C. 2006, ApJ, 650, 189
Zhao, G.-Y., et al. in preparation
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Proceedings of the International Astronomical Union
  • ISSN: 1743-9213
  • EISSN: 1743-9221
  • URL: /core/journals/proceedings-of-the-international-astronomical-union
Please enter your name
Please enter a valid email address
Who would you like to send this to? *

CAPTCHA *

Skip to the audio challenge
×

Keywords:

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 55 *
Loading metrics...

Abstract views

Total abstract views: 305 *
Loading metrics...

* Views captured on Cambridge Core between 9th February 2017 - 12th June 2018. This data will be updated every 24 hours.

Cancel
Confirm
×