Seminar by Fulvia Pucci
Zoom - September 13, 2022 - 15.00
WEBINAR LINK
Title: Magnetic reconnection in partially ionized astrophysical plasmas and local heating in protoplanetary disks.
Abstract: In many astrophysical
and space environments the plasma
is only partially ionized,
affecting the dynamics and
evolution of these systems. In
protoplanetary disks, for example,
the ionization degree depends on
the UV and X-ray photons from the
central star, which can not fully
penetrate the gas and dust in the
disk atmosphere to reach the
midplane region, where planets are
believed to form. This affects the
development of the Magneto
Rotational Instability (MRI) and
accretion onto the central star,
disk dispersal and, ultimately,
planet formation.
The interaction of charged and
neutral particles may also alter
both the triggering of magnetic
reconnection and its subsequent
dynamical evolution, affecting
local particle heating and
acceleration. I will show that
magnetic reconnection heating may
change the mid- and near-infrared
observations by the James Webb
Space Telescope of molecules, such
as water, present in disk
atmospheres.
I will then present a detailed
analytical calculation of the
onset of fast magnetic
reconnection in partially ionized
plasmas, showing the dependence of
the dynamics on collision
frequencies in different plasma
environments. I will calculate the
aspect ratio of current sheets in
the coupled, intermediate and
decoupled regimes and how this may
reflect in the energy transfer
from large to small scales, and
local heating in the plasma.
Slides
-- Related works: [1]