The role of magnetic reconnection in emission-line filaments in cooling flows

• Published in: Monthly notices of the Royal Astronomical Society Vol. 280; no. 2; pp. 438 - 446
• Main Authors: Jafelice, L. C., Friaça, A. C. S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 11.05.1996
• Subjects: cooling flows; galaxies: clusters: general; intergalactic medium; magnetic fields; MHD; X-rays: galaxies; MHD; cooling flows; intergalactic medium; galaxies: clusters: general; magnetic fields; X-rays: galaxies
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/280.2.438

Optical emission-line filaments have been observed associated with cooling flows in clusters of galaxies. It is still not known, however, what mechanism(s) are powering the optical emission of the filaments. In this work we study the effects of magnetic reconnection (MR) as an excitation mechanism of filaments in cooling flows. Here we discuss in some detail the MR process in the collisionless plasma of the intracluster medium (ICM) and estimate its efficiency. We use hydrodynamicaltime-dependent calculations to follow the evolution of cooling condensations until the phase of optical line emission. We analyse the cases in which the magnetic field is passive (i.e. it acts only as magnetic pressure) and those in which the reconnection process contributes as a heating source. Our results indicate that MR can be an important contributor to [O i] λ6300 emission in some filament systems.