| Uma GortiCurriculum Vitae: 
Projects
Evolution and Dispersal of Protoplanetary Gas Disks
NNX08AU37A
We propose to model the evolution of disks with a wide range of properties around stars of different masses, to study the lifetimes of disks and their capacity to form planets. We will use our theoretical models of the density and thermal structure of gas in disks and compute mass loss rates due to photoevaporation, a disk destruction mechanism. We will thus estimate disk lifetimes. Our models predict gas line emission and we will compare model results with observational data to infer disk properties and to better determine stellar UV luminosities, a critical parameter in setting the photoevaporation rate from the inner, planet-forming regions of disks. The constraints set by this procedure will help assess the lifetimes of disks with different initial conditions, and determine the likelihood of giant planet formation around stars. Disk properties are also expected to influence the formation of terrestrial planets in the habitable zone, and we will study the effects of gas removal by photoevaporation on planet building processes. We will thus determine the range of stellar and disk properties that are conducive to the formation of planetary systems, and therefore, to the origin of life.
Multiwavelength Studies of Gaseous Protoplanetary Disks
NNX09AC78G
We propose a multi-wavelength study of protoplanetary disks aimed at probing disk evolution by gas line emission and studying disk dispersal via photoevaporation. Gas line emission and photoevaporative flows arise mainly from the surface layers of disks, a region subject to heating by energetic photons (UV and X-rays) from the young, active, central star. We will analyse NASA's archival X-ray and UV data (ASCA, ROSAT, XMM Newton, FUSE, IUE) to obtain spectra for a well-chosen sample of sources, use available IRAS, ISO and Spitzer data to characterise infrared emission, and use our theoretical models to model observed gas emission. We will therefore derive gas spatial distributions, predict line strengths for future missions, and estimate disk dispersal times by photoevaporation due to Ultraviolet and X-ray photons.
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