| Texto completo | |
| Autor(es): |
Koshikumo, C. N.
;
Santos-Lima, R.
;
del Valle, M. V.
;
de Gouveia Dal Pino, E. M.
;
Guerrero, G.
;
Lazarian, A.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Monthly Notices of the Royal Astronomical Society; v. 542, n. 2, p. 18-pg., 2025-09-01. |
| Resumo | |
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) | |
| Processo FAPESP: | 19/05757-9 - Processos não térmicos em fontes galácticas: modelagens e previsões na iminência do CTA e ASTRI Mini-Array |
| Beneficiário: | Maria Victoria Del Valle |
| Modalidade de apoio: | Auxílio à Pesquisa - Jovens Pesquisadores |
| Processo FAPESP: | 22/10102-4 - Transporte de campos magnéticos e raios cósmicos no meio interestelar turbulento |
| Beneficiário: | Camila Naomi Koshikumo |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |
| Processo FAPESP: | 09/54006-4 - Um cluster de computadores para o Departamento de Astronomia do IAG-USP e para o Núcleo de Astrofísica da UNICSUL |
| Beneficiário: | Elisabete Maria de Gouveia Dal Pino |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa Equipamentos Multiusuários |
| Processo FAPESP: | 13/10559-5 - Investigação de fenômenos de altas energias e plasmas astrofísicos: teoria, simulações numéricas, observações e desenvolvimento de instrumentação para o Cherenkov Telescope Array (CTA) |
| Beneficiário: | Elisabete Maria de Gouveia Dal Pino |
| Modalidade de apoio: | Auxílio à Pesquisa - Projetos Especiais |
| Processo FAPESP: | 20/08729-3 - Procesos não térmicos em fontes galácticas: modelagens e previsões na iminência do CTA e ASTRI mini-array |
| Beneficiário: | Maria Victoria Del Valle |
| Modalidade de apoio: | Bolsas no Brasil - Jovens Pesquisadores |