| Texto completo | |
| Autor(es): |
Okuda, Toru
;
Singh, Chandra B.
;
Das, Santabrata
;
Aktar, Ramiz
;
Nandi, Anuj
;
de Gouveia Dal Pino, Elisabete M.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN; v. 71, n. 3, p. 15-pg., 2019-06-01. |
| Resumo | |
We examine the effects of magnetic field on low angular momentum flows with standing shock around black holes in two dimensions. The magnetic field brings change in behavior and location of the shock which results in regularly or chaotically oscillating phenomena of the flow. Adopting fiducial parameters like specific angular momentum, specific energy, and magnetic field strength for the flow around Sgr A*, we find that the shock moves back and forth in the range 60-170 R-g, irregularly recurring with a time-scale of similar to 5 d with an accompanying, more rapid, small modulation with a period of 25 hr without fading, where Rg is the Schwarzschild radius. The time-variability associated with the two different periods is attributed to the oscillating outer strong shock, together with another rapidly oscillating inner weak shock. As a consequence of the variable shock location, the luminosities vary roughly by more than a factor of 3. The time-dependent behaviors of the flow are well compatible with luminous flares with a frequency of similar to one per day and bright flares occurring every similar to 5-10 d in the latest observations by Chandra, Swift, and XMM-Newton monitoring of Sgr A*. (AU) | |
| Processo FAPESP: | 13/09065-8 - Origem e colimação de Jatos de Fontes Compactas e Mecanismos de Aceleração |
| Beneficiário: | Chandra Bahadur Singh |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| 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 |