Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-20T00:47:31.696Z Has data issue: false hasContentIssue false
  • English
  • Français

Investigating Magnetic Activity in the Galactic Centre by Global MHD Simulation

Published online by Cambridge University Press:  09 February 2017

Takeru K. Suzuki ,
Yasuo Fukui ,
Kazufumi Torii ,
Mami Machida ,
Ryoji Matsumoto  and
Kensuke Kakiuchi
Takeru K. Suzuki
Affiliation:
School of Arts & Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro, Tokyo, 153-8902, Japan email: [email protected] Dept. of Physics, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8602, Japan
Yasuo Fukui
Affiliation:
Dept. of Physics, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8602, Japan
Kazufumi Torii
Affiliation:
Dept. of Physics, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8602, Japan National Radio Observatory, National Astronomical Observatory of Japan, 462-2, Nobeyama, Minamimaki, Minamisaku, Nagano, 384-1305, Japan
Mami Machida
Affiliation:
Dept. of Physics, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
Ryoji Matsumoto
Affiliation:
Dept. of Physics, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
Kensuke Kakiuchi
Affiliation:
Dept. of Physics, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8602, Japan
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

By performing a global magnetohydrodynamical (MHD) simulation for the Milky Way with an axisymmetric gravitational potential, we propose that spatially dependent amplification of magnetic fields possibly explains the observed noncircular motion of the gas in the Galactic centre (GC) region. The radial distribution of the rotation frequency in the bulge region is not monotonic in general. The amplification of the magnetic field is enhanced in regions with stronger differential rotation, because magnetorotational instability and field-line stretching are more effective. The strength of the amplified magnetic field reaches ≳ 0.5 mG, and radial flows of the gas are excited by the inhomogeneous transport of angular momentum through turbulent magnetic field that is amplified in a spatially dependent manner. As a result, the simulated position-velocity diagram exhibits a time-dependent asymmetric parallelogram-shape owing to the intermittency of the magnetic turbulence; the present model provides a viable alternative to the bar-potential-driven model for the parallelogram shape of the central molecular zone. In addition, Parker instability (magnetic buoyancy) creates vertical magnetic structure, which would correspond to observed molecular loops, and frequently excited vertical flows. Furthermore, the time-averaged net gas flow is directed outward, whereas the flows are highly time dependent, which would contribute to the outflow from the bulge.

Keywords

accretionaccretion disks–Galaxy: bulge–Galaxy: centre–Galaxy: kinematics and dynamics–magnetohydrodynamics (MHD)–turbulence
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 11 , Symposium S322: The Multi-Messenger Astrophysics of the Galactic Centre , July 2016 , pp. 137 - 140
Copyright
Copyright © International Astronomical Union 2017 

References

Balbus, S. A., & Hawley, J. F. 1991, ApJ, 376, 214 CrossRefGoogle Scholar
Bally, J., Stark, A. A., Wilson, R. W., & Henkel, C. 1987, ApJ, 65, 13 Google Scholar
Chandrasekhar, S. 1961, Hydrodynamic and hydromagnetic stability (Oxford: Clarendon)Google Scholar
Crocker, R. M., Jones, D. I., Aharonian, F., et al. 2011, MNRAS, 411, L11 Google Scholar
Fujishita, M., Torii, K., Kudo, N., et al. 2009, PASJ, 61, 1039 CrossRefGoogle Scholar
Fukui, Y., Yamamoto, H., Fujishita, M., et al. 2006, Science, 314, 106 Google Scholar
Kudo, N., Torii, K., Machida, M., et al. 2011, PASJ, 63, 171 Google Scholar
Lang, C. C., Morris, M., & Echevarria, L. 1999, ApJ, 526, 727 CrossRefGoogle Scholar
Liszt, H. S., & Burton, W. B. 1980, ApJ, 236, 779 Google Scholar
Machida, M., Nakamura, K. E., Kudoh, T., et al. 2013, ApJ, 764, 81 Google Scholar
Machida, M., Matsumoto, R., Nozawak, S., et al. 2009, PASJ, 61, 411 Google Scholar
Miyamoto, M., & Nagai, R. 1975, PASJ, 27, 533 Google Scholar
Nishikori, H., Machida, M., & Matsumoto, R. 2006, ApJ, 641, 862 CrossRefGoogle Scholar
Nishiyama, S., Hatano, H., Tamura, M., et al. 2010, ApJ, 722, L23 Google Scholar
Parker, E. N. 1966, ApJ, 145, 811 Google Scholar
Pillai, T., Kauffmann, J., Tan, J. C., et al. 2015, ApJ, 799, 74 Google Scholar
Riquelme, D., Bronfman, L., Mauersberger, R., May, J., & Wilson, T. L. 2010, A&A, 523, A45 Google Scholar
Shibata, K., & Matsumoto, R. 1991, Nature, 353, 633 CrossRefGoogle Scholar
Suzuki, T. K., Fukui, Y., Torii, K., Machida, M., & Matsumoto, R. 2015, MNRAS, 454, 3049 Google Scholar
Suzuki, T. K., & Inutsuka, S.-i. 2009, ApJ, 691, L49 CrossRefGoogle Scholar
Suzuki, T. K., & Inutsuka, S.-i. 2014, ApJ, 784, 121 Google Scholar
Suzuki, T. K., Muto, T., & Inutsuka, S.-i. 2010, ApJ, 718, 1289 Google Scholar
Takeuchi, T., Yamamoto, H., Torii, K., et al. 2010, PASJ, 62, 557 Google Scholar
Torii, K., Kudo, N., Fujishita, M., et al. 2010a, PASJ, 62, 1307 Google Scholar
Torii, K., Kudo, N., Fujishita, M., et al. 2010b, PASJ, 62, 675 CrossRefGoogle Scholar
Tsuboi, M., Inoue, M., Handa, T., et al. 1986, AJ, 92, 818 Google Scholar
Velikhov, E. P. 1959, Zh. Eksp. Teor. Fiz., 36, 1398 Google Scholar
Yusef-Zadeh, F., Morris, M., & Chance, D. 1984, Nature, 310, 557 Google Scholar