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Study of collisionless plasma effects: application to the turbulent intracluster medium of galaxies

Grant number: 13/15115-8
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): October 01, 2013
Effective date (End): September 30, 2015
Field of knowledge:Physical Sciences and Mathematics - Astronomy
Principal Investigator:Elisabete Maria de Gouveia Dal Pino
Grantee:Reinaldo Santos de Lima
Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo, SP, Brazil

Abstract

Astrophysical plasmas can be distinguished into collisional or collisionless ones, depending on the scales of interest. In the collisional regime, the fast binary collisions rate keeps the particles thermal velocity isotropic. In this regime, the magnetohydrodynamic (MHD) theory describes the large scale dynamics of the plasma. Many important predictions of astrophysical phenomena rely on the collisional-MHD theory. These include, for example, processes related to star-formation, accretion disk formation and dynamics, turbulence in the interstellar medium, magnetic field dynamo amplification in stars and galaxies, etc. The collisional-MHD description has been applied even to collisionless astrophysical media, like the intracluster media (ICM). However, collisionless plasmas can behave very differently. For example, in the ICM the temperature anisotropy triggers electromagnetic instabilities. These instabilities in turn, interact with the particles, decreasing the anisotropy. The microphysics involved in this process is not completly understood yet. It has been demonstrated that the rate of reduction of this anisotropy alters drastically the turbulence statistics and the behavior of the dynamo amplification of the magnetic fields. All collisionless effects, the transport properties, and also the heating of particles via collisionless damping, should be taken into account in the investigation of acceleration and propagation of particles in the ICM and for a correct description of the large scale dynamics and structure of the turbulent ICM. This project aims to explore: (i) MHD models which take into account collisionless plasma effects for investigating the structure and evolution of the ICM, (ii) the interaction between the plasma instabilities and the temperature anisotropy evolution, and (iii) the acceleration and propagation of cosmic rays (CRs) in the collisionless ICM. In particular, the studies on CR propagation effects through the ICM will allow to establish new constraints and allow to make predictions for high energy detectors, in particular, for the coming Cherenkov Telescope Array (CTA). This array of about 100 telescopes will have sensitivity 10 times larger than the current gamma-ray observatories to detect the emission originated in astrophysical cosmic ray accelerators, such as active galactic nuclei, gamma-ray bursts, and galaxy cluster mergers. (AU)

Scientific publications (7)
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
SANTOS-LIMA, R.; DAL PINO, E. M. DE GOUVEIA; FALCETA-GONCALVES, D. A.; NAKWACKI, M. S.; KOWAL, G. Features of collisionless turbulence in the intracluster medium from simulated Faraday rotation maps - II. The effects of instabilities feedback. Monthly Notices of the Royal Astronomical Society, v. 465, n. 4, p. 4866-4871, MAR 2017. Web of Science Citations: 3.
SANTOS-LIMA, R.; YAN, H.; DE GOUVEIA DAL PINO, E. M.; LAZARIAN, A. Limits on the ion temperature anisotropy in the turbulent intracluster medium. Monthly Notices of the Royal Astronomical Society, v. 460, n. 3, p. 2492-2504, AUG 11 2016. Web of Science Citations: 4.
DEL VALLE, M. V.; LAZARIAN, A.; SANTOS-LIMA, R. Turbulence-induced magnetic fields in shock precursors. Monthly Notices of the Royal Astronomical Society, v. 458, n. 2, p. 1645-1659, MAY 11 2016. Web of Science Citations: 7.
GONZALEZ-CASANOVA, DIEGO F.; LAZARIAN, ALEXANDER; SANTOS-LIMA, REINALDO. MAGNETIC FIELDS IN EARLY PROTOSTELLAR DISK FORMATION. ASTROPHYSICAL JOURNAL, v. 819, n. 2 MAR 10 2016. Web of Science Citations: 4.
NAKWACKI, M. S.; KOWAL, G.; SANTOS-LIMA, R.; DE GOUVEIA DAL PINO, E. M.; FALCETA-GONCALVES, D. A. Features of collisionless turbulence in the intracluster medium from simulated Faraday Rotation maps. Monthly Notices of the Royal Astronomical Society, v. 455, n. 4, p. 3702-3723, FEB 1 2016. Web of Science Citations: 4.
DEL VALLE, M. V.; ROMERO, G. E.; SANTOS-LIMA, R. Runaway stars as cosmic ray injectors inside molecular clouds. Monthly Notices of the Royal Astronomical Society, v. 448, n. 1, p. 207-220, MAR 21 2015. Web of Science Citations: 9.
SANTOS-LIMA, R.; DE GOUVEIA DAL PINO, E. M.; KOWAL, G.; FALCETA-GONCALVES, D.; LAZARIAN, A.; NAKWACKI, M. S. MAGNETIC FIELD AMPLIFICATION AND EVOLUTION IN TURBULENT COLLISIONLESS MAGNETOHYDRODYNAMICS: AN APPLICATION TO THE INTRACLUSTER MEDIUM. ASTROPHYSICAL JOURNAL, v. 781, n. 2 FEB 1 2014. Web of Science Citations: 35.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.