| Full text | |
| Author(s): |
Koshikumo, C. N.
;
Santos-Lima, R.
;
del Valle, M. V.
;
de Gouveia Dal Pino, E. M.
;
Guerrero, G.
;
Lazarian, A.
Total Authors: 6
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 542, n. 2, p. 18-pg., 2025-09-01. |
| Abstract | |
Turbulence and magnetic fields are components of the interstellar medium and are interconnected through plasma processes. In particular, the magnetic flux transport in the presence of magnetohydrodynamic (MHD) turbulence is an essential factor for understanding star formation. The theory of reconnection diffusion (RD), based on statistics of Alfvenic turbulence, predicts a dependence of the diffusion coefficient of the magnetic field on the Alfvenic Mach number M-A . However, this theory does not consider the effects of compressibility which are important in the regime of supersonic MHD turbulence. In this work, we measure the diffusion coefficient of magnetic fields in sub-Alfvenic MHD turbulence, with different sonic Mach numbers M-S . We perform numerical simulations of forced turbulence in periodic domains from the incompressible limit to the supersonic regime. We introduce two methods to extract the diffusion coefficient, based on the analysis of tracer particles. Our results confirm the RD assumption regarding the correspondence between the diffusion of magnetic field and that of fluid Lagrangian particles. The measured diffusion rate provided by incompressible turbulence agrees with the suppression predicted by the RD theory in the presence of strong magnetic fields: D proportional to M-A(3) . Our simulations also indicate an increase in RD efficiency when the turbulence is compressible. The dependency on M-A and M-S from the simulations can be described by the relation D proportional to M-A(alpha), where alpha ( M-S ) approximate to 3 / (1 + M-S ). This quantitative characterization of D is critical for modelling star formation in turbulent molecular clouds and evaluating the efficiency of this transport compared to other mechanisms. (AU) | |
| FAPESP's process: | 19/05757-9 - Nonthermal processes in galactic sources: modelling and predictions in the CTAs and ASTRI Mini-Arrays eve |
| Grantee: | Maria Victoria Del Valle |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 22/10102-4 - Transport of magnetic fields and cosmic rays in the turbulent interstellar medium |
| Grantee: | Camila Naomi Koshikumo |
| Support Opportunities: | Scholarships in Brazil - Master |
| FAPESP's process: | 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Multi-user Equipment Program |
| FAPESP's process: | 13/10559-5 - Investigation of high energy and plasma astrophysics phenomena: theory, numerical simulations, observations, and instrument development for the Cherenkov Telescope Array (CTA) |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Special Projects |
| FAPESP's process: | 20/08729-3 - Nonthermal processes in galactic sources: modelling and predictions in the CTAs and ASTRI mini-arrays eve |
| Grantee: | Maria Victoria Del Valle |
| Support Opportunities: | Scholarships in Brazil - Young Researchers |