High energy processes in young stellar objects and high-mass X-ray binaries

Resumen

The high energy astrophysics, specifically the gamma-ray astrophysics, studies the processes that cannot be caused by hot matter but by other mechanisms colled non thermaland processes, which involve matter with energies above ~ 1 MeV. There are currently a number of instruments able to detect this radiation, such as AGILE and Fermi satellites or Cherenkov telescopes like MAGIC at the Earth's surface. In this thesis we studied two main types of systems that, as it has been observed or theoretically predicted, can produce gamma radiation : young stellar objects and high-mass X-ray binaries. Young stellar objects are found in regions of star formation, which are the cradles where new stars are being formed. The star-forming regions are populated with protostars and young stars, among other objects. Protostars still accrete matter from the parent cloud through an accretion disk, while expelling material through a jet formed by magnetic interaction. In these jets the particles are ejected at high speeds out of the system and in some cases reach relativistic velocities, as evidenced by the detection of non-thermal radio emission in some of these objects. In this thesis we are interested to find more evidence of young stellar objects that present non-thermal emission, either in the range of X-rays or gamma rays. To find new candidates have used the first catalog of the Fermi satellite and the catalogs of young systems in our Galaxy. Besides the search through catalogs, we did a study using archival X-ray XMM-Newton data on the young stellar object IRAS 16547-4247, which is known to display non-thermal radio emission. This object is a protostar still accretes material through an accretion disk and also ejects jets of material through particle. We discovered its X-ray counterpart and studied the interaction of its jets through a theoretical model. Finally, we studied a region of star formation that has been found in spatial coincidence with a second Fermi source catalog, known as Monoceros R2 . We analyzed the Fermi data from this source and our results allow us to say that the detected gamma-ray emission is consistent with that expected by the collective effects of a population of protostars. Among the other large block of this thesis there are high-mass X-ray binares. The most relevant of which we have studied is MWC 656. This system consists of a Be star and a black hole, a combination that has never been detected before. We have observed this source with XMM-Newton in X-rays and with the MAGIC Telescopes in very high energy gamma rays. Our X-ray observation has led to the discovery of the X-ray counterpart of this binary system and has allowed us to classify it as a high-mass X-ray binary, the first composed of a Be star and a black hole. Other systems we studied with MAGIC are HESS J0632 +057 and SS 433. HESS J0632 +057 is a binary system consisting of a Be star and a compact object of unknown nature and was identified by us as a gamma-ray emitter. We have also observed SS 433, the first microquasar ever discovered. We observed this source during 2010 May and June, but it has not been detected. We have calculated upper limits to the emission of very high energy gamma-rays to put constraints on the physical parameters of the system.