Massive protostars as gamma-ray sources

BOSCH-RAMON, V.; ROMERO, G. E.; ARAUDO, A. T.; PAREDES, J. M.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Año: 2010 vol. 511 p. 1 - 10

0004-6361

Massive protostars have associated bipolar outflows with velocities of hundreds of km/s. Such outflows can produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. We aim at exploring under which conditions relativistic particles are accelerated at the terminal shocks of the protostellar jets and can produce significant gamma-ray emission. We estimate the conditions necessary for particle acceleration up to very high energies and gamma-ray production in the non-thermal hot spots of jets associated with massive protostars embedded in dense molecular clouds. We show that relativistic Bremsstrahlung and proton-proton collisions can make molecular clouds with massive young stellar objects detectable by the Fermi satellite at MeV-GeV energies and by Cherenkov telescope arrays in the GeV-TeV range. Gamma-ray astronomy can be used to probe the physical conditions in star forming regions and particle acceleration processes in the complex environment of massive molecular clouds.