Cluster magnetic fields from large scale structure shocks / Medvedev Mikhail V.,Silva Luis O.,Kamionkowski Marc // . - 2007. - V. 932, l. . - P. 117+.

ISSN/EISSN:

0094-243X / нет данных

Type:

Proceedings Paper

Abstract:

The origin of the micro-Gauss magnetic fields in galaxy clusters is one of the outstanding problem of modem cosmology. We suggest that these fields could have been produced via the Weibel instability operating at shocks during the Large-Scale Structure formation and at accretion shocks in Galaxy Clusters. We have performed three-dimensional particle-in-cell simulations of the nonrelativistic Weibel instability in an electron-proton plasma (with the ion-to-electron mass ratio of 100), in conditions typical of cosmological shocks. These simulations indicate that cluster fields could have been produced by shocks propagating through the intergalactic medium during the formation of large-scale structure or by shocks within the cluster. The strengths of the shock-generated fields range from tens of nano-Gauss in the intercluster medium to a few micro-Gauss inside galaxy clusters. We discuss whether and how our results may change with the change the mass ratio to the realistic value of 1836. We stress that even if the Weibel-generated small-scale magnetic fields decay with time, they can serve as seed fields that can be further amplified and inverse-cascade to larger scales by turbulent motions of post-shock MHD turbulence.

Author keywords:

magnetic fields; large-scale structure of universe; galaxies : clusters : general shock waves; plasmas turbulence GENERATION; PLASMA; WAVES

DOI:

нет данных

Web of Science ID:

ISI:000251152400016

Соавторы в МНС:

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Другие поля

Поле	Значение
Editor	Shaikh, D and Zank, GP
Booktitle	TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS
Series	AIP Conference Proceedings
Note	6th Annual International Astrophysics Conference, Oahu, HI, MAR 16-22, 2007
Organization	IGPP UCR; Los Alamos Natl Lab; UCLA IGPP; Solana Sci
Publisher	AMER INST PHYSICS
Address	2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA
Language	English
ISBN	978-0-7354-0443-4
Keywords-Plus	GENERATION; PLASMA; WAVES
Research-Areas	Astronomy \& Astrophysics; Physics
Web-of-Science-Categories	Astronomy \& Astrophysics; Physics, Fluids \& Plasmas
ResearcherID-Numbers	Silva, Luis/C-3169-2009
ORCID-Numbers	Silva, Luis/0000-0003-2906-924X
Funding-Acknowledgement	DoE {[}DE-FG02-04ER54790, DEFG03-92- ER40701]; NASA {[}NNG-04GM41G, NNG05GF69G]; GRF; LOS; FCT {[}PDCT/FP/FAT/50190/2003, 4 POCI/FIS/55905/2004]
Funding-Text	LOS acknowledges the help of Michael Marti in performing the simulations, M. Tzonfres, M. Marti, Profs. Ricardo Fonseca and Warren Mori for discussions. MK acknowledges useful discussions with X. Chen, E. Nakar, and M. Milosavljevic. The simulations were performed in the eXpp cluster at IST, Lisbon. The work of MVM has been supported by DoE grant DE-FG02-04ER54790, NASA grant NNG-04GM41G, and the GRF fund. The work of LOS was partially supported by FCT (Portugal) through grants PDCT/FP/FAT/50190/2003 and 4 POCI/FIS/55905/2004. MK was supported by DoE DEFG03-92- ER40701 and NASA NNG05GF69G.
Number-of-Cited-References	14
Doc-Delivery-Number	BGX51