Magnetic field orientation in self-gravitating turbulent molecular clouds

Autor(es)

Barreto-Mota, L. ^[1] ; Dal Pino, E. M. de Gouveia ^[1] ; Burkhart, B. ^{[2, 3]} ; Melioli, C. ^[4] ; Santos-Lima, R. ^[1] ; Kadowaki, L. H. S. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Astron Geofis & Ciencias Atmosfer USP, R Matao 1226, BR-05508090 Sao Paulo, SP - Brazil

^[2] Rutgers State Univ, Dept Phys & Astron, 136 Frelinghuysen Rd, Piscataway, NJ 08854 - USA

^[3] Flatiron Inst, Ctr Computat Astrophys, 162 Fifth Ave, New York, NY 10010 - USA

^[4] Univ Modena & Reggio Emilia UNIMORE, Dipartimento Sci & Metodi Ingn, Via Amendola 2, I-42122 Reggio Emilia - Italy

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 503, n. 4, p. 5425-5447, JUN 2021.
• Citações Web of Science: 2

Resumo

Stars form inside molecular cloud filaments from the competition of gravitational forces with turbulence and magnetic fields. The exact orientation of these filaments with the magnetic fields depends on the strength of these fields, the gravitational potential, and the line of sight (LOS) relative to the mean field. To disentangle these effects we employ three-dimensional magnetohydrodynamical numerical simulations that explore a wide range of initial turbulent and magnetic states, i.e. sub-Alfvenic to super-Alfvenic turbulence, with and without gravity. We use histogram of relative orientation (HRO) and the associated projected Rayleigh statistics (PRS) to study the orientation of density and, in order to compare with observations, the integrated density relative to the magnetic field. We find that in sub-Alfvenic systems the initial coherence of the magnetic is maintained inside the cloud and filaments form perpendicular to the field. This trend is not observed in super-Alfvenic models, where the lines are dragged by gravity and turbulence and filaments are mainly aligned to the field. The PRS analysis of integrated maps shows that LOS effects are important only for sub-Alfvenic clouds. When the LOS is perpendicular to the initial field orientation most of the filaments are perpendicular to the projected magnetic field. The inclusion of gravity increases the number of dense structures perpendicular to the magnetic field, reflected as lower values of the PRS for denser regions, regardless of whether the model is sub- or super-Alfvenic. The comparison of our results with observed molecular clouds reveals that most are compatible with sub-Alfvenic models. (AU)

• 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: 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: 16/12320-8 - Estudo numérico de reconexão magnética ao redor de buracos negros
• Beneficiário: Luis Henrique Sinki Kadowaki
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado