ABDES · An astrochemical study of the early evolutionary stages of sub-stellar mass objects

An astrochemical study of the early evolutionary stages of sub-stellar mass objects

Over the last decade, extensive observational and theoretical effort has been invested to understand the early stages of evolution of Sun-like stars. Similar studies are still very sparse for stars at the very low-mass end, with masses less than one-tenth of the mass of the Sun. Often termed as the least massive known ‘stars’, brown dwarfs (BDs) are sub-stellar objects that have insufficient mass to burn hydrogen in their cores and shine like stars. Yet, these faint astronomical objects are found to be as numerous as Sun-like stars in various star-forming regions, thereby making them an equally vital constituent of our Galaxy. Any research on star formation in the Milky Way is thus incomplete without gaining a comprehensive knowledge on the early stages of evolution of the least massive but ubiquitous component of the Galaxy. My MSCA-IF project, named ABDES, was an extensive observational and theoretical investigation of the diverse properties of BDs during their early Class I stage of evolution. To conduct this study, I have combined high-quality multi-wavelength observations using high-class telescopes and instruments, and new, state-of-the-art physical and chemical models developed exclusively for early-stage BDs. This has allowed a successful completion of the different tasks in the project. The objectives and methodologies of the project were: a) to combine multi-wavelength observations with state-of-the-art models and conduct an in-depth study of the internal physical and chemical structure, kinematics, dynamics, and chemical composition in Class I BDs; b) to investigate the fundamental role played by accretion and outflow processes in shaping the evolution of Class I BDs using optical/near-infrared spectra and images. This survey has looked into the analogies in the various characteristics of BDs and Sun-like stars during their early evolutionary stages. The fundamental questions that the project aimed to answer were: (i) Is the initial chemical composition and the internal physical and chemical structure of Class I BDs similar to Class I Sun-like stars? (ii) Are the accretion and outflow processes during the early evolutionary phases as intense for BDs as observed for Sun-like stars? (iii) Is there a continuity in the formation and early evolutionary processes across the stellar/sub-stellar boundary? The ABDES project has delivered the first of its kind results on the fundamental properties of sub-stellar objects during their initial formation stages. It has provided the first detailed derivation of the physical and chemical composition of an early-stage BD, and has advanced our understanding of star formation in the Galaxy at the sub-stellar mass end.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз