Learning by Research

Thesis Title: Hot Corinos: the early organic molecular enrichment of the planet formation zones.

So far Earth is the only known planet hosting life, which is based on organic chemistry. Interestingly, some of the chemical precursors of life, e.g. amino acid, have been found in Solar System objects (e.g., comets and meteorites). This finding supports the possibility that the first steps of organic chemistry started already during the early stages of the formation of our Solar System. However, is it actually true?Planetary systems as the Solar System are formed continuously in the Milky Way so that it is possible to study them to recover what happened to our Solar System.The formation of Solar-type stars goes through different stages, starting from a collapsing molecular core that evolves into a protostar, a protoplanetary disk, and eventually a planetary system. Together with the physical evolution, a chemical evolution takes place.In particular, several relatively complex organic molecules have been detected in the early protostellar phase, i.e., hot corinos. Therefore, their chemical characterization is a crucial point in retrieving our origins.Nevertheless, after almost twenty year of studies, very few hot corinos have been discovered, and many of them show very different molecular spectra at millimeter wavelengths.In this perspective, with this Thesis I aim to answer two main questions: i) What is the origin and nature of hot corinos?ii) How are interstellar complex organic molecules synthesized?

In order to answer these questions, I investigated the protostellar binary system NGC 1333 IRAS 4A and its surrounding environment. This system, extensively studied at millimeter wavelengths, is composed of two sources, IRAS 4A1 and IRAS 4A2, with very different millimeter molecular spectra. Additionally, the two protostars are ejecting two bipolar outflows that interact with the surrounding envelope.I used i) VLA centimeter wavelengths observations toward the two protostars to investigate their chemical nature and history and ii) high-angular resolution observations with NOEMA, as part of the SOLIS (Seeds of Life in Space) Large Program, to study the chemical complexity of their molecular outflows.This Thesis work is part of the project Dawn of Organic Chemistry (DOC), funded by the European Research Council (ERC) under the grant No 741002.

Key Words: Hot corinos, Molecular richness, Outflow

Doctoral School: ED PHYS – Physics
Research laboratory: Institut de Planétologie et d’Astrophysique de Grenoble (IPAG - CNRS/UGA)
Thesis supervision: Cecilia CECCARELLI and Claudio CODELLA

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