Turbulence-induced magnetic fields in shock precursors

Autor(es)

del Valle, M. V. ^[1] ; Lazarian, A. ^[2] ; Santos-Lima, R. ^[3]

Afiliação do(s) autor(es)

^[1] Inst Argentino Radioastron, CC-5, RA-1894 Buenos Aires, DF - Argentina

^[2] Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 - USA

^[3] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 458, n. 2, p. 1645-1659, MAY 11 2016.
• Citações Web of Science: 8

Resumo

Galactic cosmic rays are believed to be mostly accelerated at supernova shocks. However, the interstellar magnetic field is too weak to efficiently accelerate galactic cosmic rays up to the highest energies, i.e. 10(15) eV. A stronger magnetic field in the pre-shock region could provide the efficiency required. Bell's cosmic ray non-resonant streaming instability has been claimed to be responsible for the amplification of precursor magnetic fields. However, an alternative mechanism has been proposed in which the cosmic ray pressure gradient forms the shock precursor and drives turbulence, amplifying the magnetic field via the small-scale dynamo. Key ingredients for the mechanism to operate are the inhomogeneities present in the interstellar medium. These inhomogeneities are the consequence of turbulence. In this work we explore the magnetic field amplification in different interstellar medium conditions through 3D magnetohydrodynamic numerical simulations. (AU)

• 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
• Linha de fomento: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 13/15115-8 - Estudo de efeitos de plasma não-colisional: aplicação ao meio intra-aglomerado de galáxias
• Beneficiário: Reinaldo Santos de Lima
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado