Plasma and Fusion Research

Volume 14, 4406119 (2019)

Regular Articles

Using Combined PIC and MHD to Model Particle Acceleration in Galaxy Cluster Shocks
Allard Jan VAN MARLE, Dongsu RYU, Hyesung KANG1) and Ji-Hoon HA
Department of Physics, UNIST, UNIST-gil 50, Ulsan 44919, Korea
1)
Department of Earth Sciences, Pusan National University, Busan 46241, Korea
(Received 20 December 2018 / Accepted 10 May 2019 / Published 9 September 2019)

Abstract

When clusters of galaxies merge, shocks are formed that are characterized by a low (1-4) sonic Mach number and an Alfvénic Mach number that is typically an order of magnitude higher, giving the shocks a plasma β of approximately 100. The question we seek to answer is to what extent shocks can accelerate particles to relativistic speeds and thereby contribute to the cosmic ray spectrum. We use a combined particle-in-cell and magnetohydrodynamics code, which treats the thermal plasma as a fluid, but uses a kinetic approach to deal with non-thermal particles. This approach is computationally cheaper than the traditional PIC method while preserving the ability to deal with non-thermal particles. Our preliminary results confirm the ability of shocks in the low-Mach, high-β regime that characterizes galaxy cluster merger shocks to accelerate particles depends strongly on the input parameters, which was previously shown with PIC simulations.

Keywords

astrophysical shock, galaxy cluster, particle acceleration, method, numerical

DOI: 10.1585/pfr.14.4406119

Full Text

PDF format (2.0Mbytes) PDF Download

References

  • [1] F. Miniati, D. Ryu, H. Kang, T.W. Jones, R. Cen and J.P. Ostriker, Astrophys. J. 542, 608 (2000).
  • [2] D. Ryu, H. Kang, E. Hallman and T.W. Jone, Astrophys. J. 593, 599 (2003).
  • [3] A.R. Bell, Mon. Not. R. Astron. Soc. 182, 147 (1978).
  • [4] R.D. Blandfort and J.P. Ostriker, Astrophys. J. Lett. 221, L29 (1978).
  • [5] L.O'C. Drury, Rep. Prog. Phys. 46, 973 (1983).
  • [6] A. Pinzke and C. Pfrommer, Mon. Not. R. Astron. Soc. 409, 449 (2010).
  • [7] F. Zandanel and S. Ando, Mon. Not. R. Astron. Soc. 440, 663 (2014).
  • [8] H. Kang and D. Ryu, Astrophys. J. 856, 33 (2018).
  • [9] M. Ackermann, M. Ajello, A. Allafort et al., Astrophys. J. Lett. 819, 149 (2016).
  • [10] F. Vazza, M. Brüggen, D. Wittor et al., Mon. Not. R. Astron. Soc. 459, 70 (2016).
  • [11] X.-N. Bai, D. Caprioli, L. Sironi and A. Spitkovsky, Astrophys. J. 809, 55 (2015).
  • [12] D. Caprioli and A. Spitkovsky, Astrophys. J. 783, 91 (2014a).
  • [13] D. Caprioli and A. Spitkovsky, Astrophys. J. 94, 46 (2014b).
  • [14] D. Caprioli, A. Pop and A. Spitkovsky, Astrophys. J. Lett. 798, 28 (2015).
  • [15] A.J. van Marle, F. Casse and A. Marcowith, Mon. Not. R. Astron. Soc. 473, 3394 (2018).
  • [16] J.-H. Ha, D. Ryu, H. Kang and A.J. van Marle, Astrophys. J. 864, 105 (2018).
  • [17] J.P. Edmiston and C.F. Kennel, Plasma Phys. 32, 429 (1984).
  • [18] B. Reville, S. O'Sullivan, P. Duffy and J.G. Kirk, Mon. Not. R. Astron. Soc. 386, 509 (2013).
  • [19] B. Reville and A. Bell, Mon. Not. R. Astron. Soc. 430, 2873 (2013).
  • [20] B. van der Holst, B.R. Keppens and Z. Meliani, Comput. Phys. Commun. 179, 617 (2008).
  • [21] M.S. Shephard and M.K. Georges, Int. J. Numer. Methods Eng. 32, 709 (1991).
  • [22] C.K. Birdsall and A.B. Langdon, Plasma Physics via Computer Simulation (The Adam Hilger Series on Plasma Physics, edited by C. Birdsall and A. Langdon. Adam Hilger, Bristol, England, 1991).