The Shear-Current Effect: An Extended Analysis

Following the work of J. Squire and A. Bhattacharjee[1], we investigate the shear-current effect (SCE) as a mean-field dynamo (MFD) mechanism in accretion disks. We first verify the previous results using a new code, Athena++, by performing an ensemble of unstratified zero-net-vertical-flux shearing box simulations. The SCE is then verified using both test-field and least-squares methods to compute the dynamo coefficients, assuming the standard closure model for the electromotive force. We subsequently investigate the effects of shearing box vertical aspect ratio and spatial resolution, following [2]. Further extension to boxes with net vertical flux, stratification, and the inclusion of non-ideal MHD terms is also considered.

[1] Squire, J. and Bhattacharjee, A., Phys. Rev. Lett. 115, no. 17, 175003 (2015) doi:10.1103/PhysRevLett.115.175003

[2] J. M. Shi, J. M. Stone and C. X. Huang, Mon. Not. Roy. Astron. Soc. 456, no. 3, 2273 (2016) doi:10.1093/mnras/stv2815 [arXiv:1512.01106 [astro-ph.HE]].