Ph.D. in Astronomy, 2007, UNLP, Argentina, "Gamma-ray emission from accreting binary systems"
Current position: Researcher (IAR - CONICET), and Head of Practice, University of La Plata (FCAyG-UNLP), Argentina
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 2009/2010 I have tryed on
protoplanetary disks'
investigation, as a postdoctoral fellow at the University of
Valparaíso, Chile. This allowed me to know the passive accretion disks
(i.e. that reprocess the central YSO light), which are studied
mostly through their IR emission. This project is leaded by Dr. Lucas A.
Cieza and is aimed to find the most exciting targets to be followed up
by ALMA.