Abstract
The heating and acceleration of ions during magnetic reconnection relevant to coronal heating and flares is explored via particle-in-cell (PIC) simulations and analytic modeling. We show that the dominant heating mechanism of sub-Alvénic ions during reconnection with a guide field, the case of greatest relevance to the corona, results from pickup behavior during the entry into reconnection exhausts, which produces effective thermal speeds of the order of the Alfvén velocity based on the reconnecting magnetic field. There is a mass-to-charge (M/Q) threshold for pickup behavior that favors the heating of high-M/Q ions. Ions below the threshold gain little energy beyond that associated with convective flow. PIC simulations with protons and alphas confirm the pickup threshold. The enhanced heating of high M/Q ions is consistent with observations of abundance enhancements of such ions in impulsive flares. In contrast to anti-parallel reconnection, the temperature increment during ion pickup is dominantly transverse, rather than parallel, to the local magnetic field. The simulations reveal the dominance of perpendicular heating, which is also consistent with observations.
We suggest that the acceleration of ions to energies well above that associated with the Alfvén speed takes place during the interaction with many magnetic islands, which spontaneously develop during 3-D guide-field reconnection. The exploration of particle acceleration in a full 3-D multi-island system remains computationally intractable. Instead we explore ion acceleration in a multi-current layer system with low initial β. Ion energy gain takes place due to Fermi reflection in contracting and merging magnetic islands. Particle acceleration continues until the available magnetic free-energy is significantly depleted so that the pressure of energetic ions approaches that of the reconnecting field. Depending on the strength of the ambient guide field and in spite of the low initial plasma β, the dominance of parallel heating can cause significant regions of the plasma to exceed the marginal firehose condition.
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References
P.J. Cargill, Astrophys. J. 422, 381 (1994)
S.R. Cranmer, A.A. van Ballegooijen, Astrophys. J. 594, 573 (2003)
W. Daughton, V. Roytershteyn, H. Karimabadi, L. Yin, B.J. Albright, B. Bergen, K.J. Bowers, Nat. Phys. 7, 539 (2011)
J.F. Drake, M. Swisdak, H. Che, M.A. Shay, Nature 443, 553 (2006a)
J.F. Drake, M. Swisdak, K.M. Schoeffler, B.N. Rogers, S. Kobayashi, Geophys. Res. Lett. 33, L13105 (2006b)
J.F. Drake, P.A. Cassak, M.A. Shay, M. Swisdak, E. Quataert, Astrophys. J. 700, L16 (2009a)
J.F. Drake, et al., J. Geophys. Res. 114, A05111 (2009b)
J.F. Drake, M. Opher, M. Swisdak, J.N. Chamoun, Astrophys. J. 709, 963 (2010)
A.G. Emslie, et al., J. Geophys. Res. 109, A10104 (2004)
L.A. Fisk, G. Gloeckler, Astrophys. J. 640, L79 (2006)
T.G. Forbes, J.M. Malherbe, E.R. Priest, Sol. Phys. 120, 285 (1989)
A.A. Galeev, M.M. Kuznetsova, L.M. Zeleny, Space Sci. Rev. 44, 1 (1986)
K. Galsgaard, A. Nordlund, J. Geophys. Res. 101, 13445 (1996)
J.T. Gosling, R.M. Skoug, D.J. McComas, Geophys. Res. Lett. 110, A01107 (2005)
M. Hesse, K. Schindler, J. Birn, M. Kuznetsova, Phys. Plasmas 5, 1781 (1999)
G.D. Holman, Astrophys. J. 293, 584 (1985)
M. Hoshino, T. Mukai, T. Yamamoto, J. Geophys. Res. 103, 4509 (1998)
K. Kniznik, M. Swisdak, J.F. Drake, Astrophys. J. 743, L35 (2011)
J.L. Kohl, et al., Sol. Phys. 175, 613 (1997)
J.L. Kohl, et al., Astrophys. J. 501, 127 (1998)
D. Krauss-Varban, B.T. Welsch, in Highlights of Astronomy, vol. 14, ed. by K.A. van der Hucht (Cambridge Univ. Press, Cambridge, 2006), p. 89
R.P. Lin, H.S. Hudson, Sol. Phys. 17, 412 (1971)
Y.E. Litvinenko, Astrophys. J. 462, 997 (1996)
Y.-H. Liu, J.F. Drake, M. Swisdak, Phys. Plasmas 18, 062110 (2011)
D.W. Longcope, A.C.D. Jardins, R. Carranza-Fulmer, J. Qiu, Sol. Phys. 267, 107 (2010)
G.M. Mason, Space Sci. Rev. 130, 231 (2007)
J.A. Miller, Space Sci. Rev. 86, 79 (1998)
J.A. Miller et al., J. Geophys. Res. 102, 14631 (1997)
E. Möbius, D. Hovestadt, B. Klecker, M. Scholer, G. Gloeckler, F.M. Ipavich, Nature 318, 426 (1985)
M. Oka, T.D. Phan, S. Krucker, M. Fujimoto, I. Shinohara, Astrophys. J. 714, 915 (2010)
M. Onofri, H. Isliker, L. Vlahos, Phys. Rev. Lett. 96, 151102 (2006)
E.N. Parker, Astrophys. J. 264, 642 (1983)
V. Petrosian, S. Liu, Astrophys. J. 610, 550 (2004)
T.D. Phan et al., Geophys. Res. Lett. 34, L14104 (2007)
T.D. Phan et al., Astrophys. J. 719, L199 (2010)
K.M. Schoeffler, J.F. Drake, M. Swisdak, Astrophys. J. 743, 70 (2011)
K.M. Schoeffler, J.F. Drake, M. Swisdak, K. Knizhnik, Astrophys. J. (2012), submitted
R. Schreier, M. Swisdak, J.F. Drake, P.A. Cassak, Phys. Plasmas 17, 110704 (2010)
M.A. Shay, J.F. Drake, Geophys. Res. Lett. 25, 3759 (1998)
M.A. Shay, J.F. Drake, M. Swisdak, Phys. Rev. Lett. 99, 155002 (2007)
B.V. Somov, R. Kosugi, Astrophys. J. 485, 859 (1997)
A. Zeiler, D. Biskamp, J.F. Drake, B.N. Rogers, M.A. Shay, M. Scholer, J. Geophys. Res. 107, 1230 (2002). doi:10.1029/2001JA000287
Acknowledgements
This work has been supported by NSF Grant ATM-0903964 and NASA grants APL-975268 and NNX09AI02G. Computations were carried out at the National Energy Research Scientific Computing Center.
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Drake, J.F., Swisdak, M. Ion Heating and Acceleration During Magnetic Reconnection Relevant to the Corona. Space Sci Rev 172, 227–240 (2012). https://doi.org/10.1007/s11214-012-9903-3
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DOI: https://doi.org/10.1007/s11214-012-9903-3