Matteo Pinamonti (Uni-TS, Trieste, IT)
 
"Detection and Orbital Architecture Characterization of Planetary Systems Around Cool Stars"

It is pivotal to intensify the efforts towards the detection and characterization of extrasolar planets around M dwarfs, since new discoveries will help bring the statistical support still needed for the study of peculiar classes of planets. The many open issues on M dwarfs host and their planetary systems, and the development of new methodologies to investigate them, are the foundation of the motivation for my PhD work. I report my work on performance analysis of three periodogram tools, the Generalised Lomb-Scargle Periodogram, its modified version based on Bayesian statistics, and the multi-frequency periodogram scheme called Frequency Decomposer. The results illustrated reinforce the need for the strengthening and further developing of the most aggressive and effective ab initio strategies for the robust identification of low-amplitude planetary signals in RV data sets. I describe the high-performance algorithms for single and multiple Keplerian signals modeling used by the research group I am part of, and their applications both on blindly analyzed simulated RV measurements and on high-precision HARPS archive data. I then report the first results I obtained from the analysis of RV data collected as part of the HADES (HArps-n red Dwarf Exoplanet Survey) project, that is the detection of a long-period low-mass planet orbiting the M1 dwarf GJ15A, which was already known to host a short-period Super Earth. Since the host star is part of a binary system with the M dwarf GJ15B, I studied a suite of numerical simulations of the long-term perturbations of the planetary system. Finally, I outline the strategy and preliminary results of the ongoing Bayesian analysis of the occurrence rates of planets around small mass stars and the global detectability of the HADES survey.

Anna Zoldan (Uni-TS, Trieste, IT)

"On the role of cold gas in galaxy evolution"

Galaxy evolution results from a complex interplay of physical processes, that act on a wide range of scales and times. One crucial piece of this complex puzzle is cold gas. Indeed, all physical processes occurring within galaxies, as well as those related to interactions with the external environment, directly influence (or are regulated by) the dynamics and the content of cold gas. In this seminar, I will provide a brief overview of my PhD Thesis. I have taken advantage of state-of-the-art semi-analytical models of galaxy formation and evolution, and used them to explore the role of cold gas in the physical processes driving galaxy evolution. This approach allows a controlled analysis of individual galaxy histories, and of the contributions of the specific processes involved. I can, in this way, follow the origin of the observed relations, providing a physical interpretation for existing data and predictions for higher redshift.