[Todos] Recordatorio: IAFE- COLOQUIOS CIENTÍFICOS: Viernes 11 de Diciembre de 2015 a las 14:0 0 hs.

["Area Difusión IAFE"]

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                          COLOQUIOS CIENTÍFICOS

               Instituto de Astronomía y Física del Espacio
                             CONICET-UBA
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         " A Study of Radio Polarization in Protostellar Jets."

                           Pablo Velazquez
                               ICN-UNAM
                  Viernes 11 de Diciembre de 2015 a las 14:00 hs.
                            Aula del Edificio IAFE

Synchrotron radiation is commonly observed in connection with shocks of
different velocities, ranging from relativistic shocks associated with
active galactic nuclei, gamma-ray bursts or microquasars to weakly- or
non-relativistic flows as those observed in supernova remnants. Recent
observations of synchrotron emission in protostellar jets are important
not only because they extend the range over which the acceleration process
works, but also because they allow to determine the jet and/or
interstellar magnetic field structure, thus giving insights on the jet
ejection and collimation mechanisms. In this paper, we compute for the
first time polarized (synchrotron) and non polarized (thermal X-ray)
synthetic emission maps from axisymmetrical simulations of magnetized
protostellar jets. We consider models with different jet velocities and
variability, as well as toroidal or helical magnetic field. Our
simulations show that variable, low-density jets with velocities ~1000
km/s and ~10 times lighter than the environment can produce internal knots
with significant synchrotron emission, and thermal X-rays in the shocked
region of the leading bow shock moving in a dense medium. While models
with a purely toroidal magnetic field show a very large degree of
polarization, models with helical magnetic field show lower values and a
decrease of the degree of polarization, in agreement with observations of
protostellar jets.