Speaker
Dr
Anabella Araudo
(Astronomical Institute of the Czech Academy of Sciences)
Description
Supersonic and collimated bipolar jets are launched from the inner
regions of accretion discs in forming stars. Jets from young stellar objects
are well known thermal emitters.
However, non-thermal radio emission from a handful of protostellar jets
has been reported in the last years. The detection of
synchrotron radiation indicates the presence of relativistic electrons and
magnetic fields of about 0.1 mG. Protons can be accelerated as well.
Below certain conditions, non-resonant hybrid (Bell)
instabilities can be excited by the streaming of protons being accelerated
and the magnetic field is amplified.
We study diffusive shock acceleration and
magnetic field amplification in protostellar jets with velocities
~500 km/s. The maximum energy that electrons and protons
can achieve is constrained by escape and radiative losses, as well as damping of
scattering waves, where the ionization of the plasma plays an
important role. We find that both electrons and protons can be accelerated up the
TeV domain and therefore emit gamma rays in
their interaction with photon and matter fields. The detection of
this radiation by the
forthcoming Cherenkov Telescope Array will open a
new window to study the formation of massive stars, as well as
diffusive acceleration and magnetic field amplification in
astrophysical shocks with velocities of about 500 km/s.
Primary author
Dr
Anabella Araudo
(Astronomical Institute of the Czech Academy of Sciences)
Co-authors
Dr
Alexandre Marcowith
(Laboratoire Univers et Particules de Montpellier (LUPM))
Dr
Marco Padovani
(Arcetri Astrophysical Observatory)
