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ABSTRACT: Elias 29 is a Class I star of the young star forming site of the Rho Ophiuchi Dark Cloud.In X-rays it shows a prominent fluorescent line at 6.4 keV which origin is still to be clearly understood. The excitation of fluorescence of cold material could be due to hard X-ray photons especially produced during flares or to high energy electrons. I will report on a recent joint and simultaneous XMM + NuSTAR of about 300 ks meant to investigate X-rays from soft to hard band (approx. 0.3-80 keV). In particular, I will discuss the analysis of a bright flare of modest duration (20 ks), the fluorescent emission and its variability and the hard X-ray emission in the NuSTAR band (10-80 keV).

Lo studente Vincenzo Sapienza presenta il suo lavoro di tesi per la Laurea Triennale.

Partendo da analisi di tipo sociologico e statistico del XX secolo, saranno discusse le difficoltà incontrate dalle donne nella carriera scientifica e le potenzialità del loro contributo allo sviluppo della scienza.

ABSTRACT:

Only a very small fraction of the organic compounds in nature are found in planets or comets and other  condensed objects. By far the larger quantity, more than 99.9% by mass, reside in the enormous molecular clouds in interstellar space of the Milky Way and other galaxies. Abiotic organic chemistry, as observed in molecular clouds, offers a glimpse of the chemical evolution preceding the onset of life on our own planet,  and allows us to evaluate the possibility that – during the evolution from a molecular cloud to a planetary system – complex organic molecules are formed, transformed and preserved until they are incorporated into comets and meteorites. The analyses of such cosmic debris show that some of the amino acids present an excess of the L-conformation enantiomer in straightforward similarity with terrestrial biomolecular homochirality. This coincidence is too striking to be fortuitous; it points out that products of routine cosmic chemistry contributed to the early Earth organic pool and facilitated prebiotic molecular evolution.

Among the many scenarios put forward to explain the origin of chiral homogeneity, one involves the asymmetric photolysis of amino acids present in space, triggered by circularly polarized ultraviolet radiation.
Here we propose that amino acids formed in the cavities of interstellar dust aggregates are
exposed to asymmetric photolysis induced by an effective ultraviolet circularly polarization generated in situ.

Visita delle studentesse del corso di laurea in Conservazione e Restauro dei Beni Culturali, accompagnate dal docente Marco Di Bella

a cura di Donata Randazzo e Giada Genua