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Investigating Magnetic Activity in the Galactic Centre by Global MHD Simulation

  • Takeru K. Suzuki (a1) (a2), Yasuo Fukui (a2), Kazufumi Torii (a2) (a3), Mami Machida (a4), Ryoji Matsumoto (a5) and Kensuke Kakiuchi (a2)...

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.

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Balbus, S. A., & Hawley, J. F. 1991, ApJ, 376, 214
Bally, J., Stark, A. A., Wilson, R. W., & Henkel, C. 1987, ApJ, 65, 13
Chandrasekhar, S. 1961, Hydrodynamic and hydromagnetic stability (Oxford: Clarendon)
Crocker, R. M., Jones, D. I., Aharonian, F., et al. 2011, MNRAS, 411, L11
Fujishita, M., Torii, K., Kudo, N., et al. 2009, PASJ, 61, 1039
Fukui, Y., Yamamoto, H., Fujishita, M., et al. 2006, Science, 314, 106
Kudo, N., Torii, K., Machida, M., et al. 2011, PASJ, 63, 171
Lang, C. C., Morris, M., & Echevarria, L. 1999, ApJ, 526, 727
Liszt, H. S., & Burton, W. B. 1980, ApJ, 236, 779
Machida, M., Nakamura, K. E., Kudoh, T., et al. 2013, ApJ, 764, 81
Machida, M., Matsumoto, R., Nozawak, S., et al. 2009, PASJ, 61, 411
Miyamoto, M., & Nagai, R. 1975, PASJ, 27, 533
Nishikori, H., Machida, M., & Matsumoto, R. 2006, ApJ, 641, 862
Nishiyama, S., Hatano, H., Tamura, M., et al. 2010, ApJ, 722, L23
Parker, E. N. 1966, ApJ, 145, 811
Pillai, T., Kauffmann, J., Tan, J. C., et al. 2015, ApJ, 799, 74
Riquelme, D., Bronfman, L., Mauersberger, R., May, J., & Wilson, T. L. 2010, A&A, 523, A45
Shibata, K., & Matsumoto, R. 1991, Nature, 353, 633
Suzuki, T. K., Fukui, Y., Torii, K., Machida, M., & Matsumoto, R. 2015, MNRAS, 454, 3049
Suzuki, T. K., & Inutsuka, S.-i. 2009, ApJ, 691, L49
Suzuki, T. K., & Inutsuka, S.-i. 2014, ApJ, 784, 121
Suzuki, T. K., Muto, T., & Inutsuka, S.-i. 2010, ApJ, 718, 1289
Takeuchi, T., Yamamoto, H., Torii, K., et al. 2010, PASJ, 62, 557
Torii, K., Kudo, N., Fujishita, M., et al. 2010a, PASJ, 62, 1307
Torii, K., Kudo, N., Fujishita, M., et al. 2010b, PASJ, 62, 675
Tsuboi, M., Inoue, M., Handa, T., et al. 1986, AJ, 92, 818
Velikhov, E. P. 1959, Zh. Eksp. Teor. Fiz., 36, 1398
Yusef-Zadeh, F., Morris, M., & Chance, D. 1984, Nature, 310, 557
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Proceedings of the International Astronomical Union
  • ISSN: 1743-9213
  • EISSN: 1743-9221
  • URL: /core/journals/proceedings-of-the-international-astronomical-union
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