Dr. Mariana Orellana

   M.Sc. in Astronomy, 2004, UNLP, Argentina
Ph.D. in Astronomy, 2007, UNLP, Argentina, "Gamma-ray emission from accreting binary systems"
Current position: Postdoc, Valparaíso Univ., Chile

CV
Publication list

Contact: morellana@fcaglp.unlp.edu.ar

In my diploma work for the M. Sc. degree (Licenciatura) I made some calculations about the high-energy gamma-ray emission of highly magnetized accreting neutron stars in Be/X-ray binaries. In that kind of systems the high energy photons are created as a consecuence of the impact onto the accretion disk of protons acelerated in the magnetosphere by the Cheng-Ruderman mechasnism. I analyzed mean features of electromagnetic cascades developed inside the accretion disk and the opacity of the photosphere during the occurrence of a giant X-ray burst.
The topic of my research is the astrophysic of gamma-ray sources, mainly from a theoretical point of view. Specifically, the recent collaborations in which I participated, have concerned the high-energy gamma-ray emission and its propagation inside high mass X-ray binaries (e.g. in microquasars ). In those systems (such as the fascinating LS I +61 303) the gamma-ray emission is believed to arise from hadronic interactions between relativistic protons in the jet and cold protons from the wind. Secondary processes including leptonic emission and electromagnetic cascading should be taken into account for a complete model.
Recently, I concluded my Ph. D. studies under the direction of Dr. G.E. Romero, working at the facilities of both Instituto Argentino de Radioastronomía and the FCAGLP's observatory. My ongoing research has turned to include AGNs as emitters not only of photons throughout the electromagnetic spectrum, but also of ultra-high energy cosmic rays, as was reclently confirmed by the Auger observatory.
As an interlude, in 2009 I am about to participate on protoplanetary disks' investigation, as a postdoctoral fellow of the University of Valparaiso.