Evolution of Ionized Interstellar Medium across Cosmic Time
Fuyan Bian, European Southern Observatory
The ionized interstellar medium (ISM) provides essential information on the star-forming environments, metal enrichment, and underlying ionizing radiation field in galaxies. It is crucial to understand how the ionized ISM evolves with Cosmic time. In this talk, I will present a sample of local galaxies that closely resemble the properties of high-redshift galaxies at high redshift. These local analogs of high-redshift galaxies provide a unique local laboratory to study high-redshift galaxies. I will discuss how to use these analogs to improve our understanding of the high-redshift metallicity empirical calibrations and physical mechanism(s) to drive the evolution of optical diagnostics lines from high redshift to low redshift.
The role if the intergalactic medium in the baryon cycle
Valentina D’Odorico, INAF Osservatorio Astronomico di Trieste
The intergalactic medium (IGM) plays a relevant role in galaxy evolution being the reservoir of gas for star formation and, at the same time, collecting the products of star formation ejected from galaxies. The IGM is studied mainly in absorption, in the spectra of high redshift bright objects. In this talk, I will briefly review the recent development in the study of the IGM, in particular the determination of its metal enrichment, in the context of the baryon cycle in galaxies. I will focus my presentation on the high redshift regime, reaching the epoch of reionization, where strong constraints are set to the models of galaxy evolution.
Planet formation in protoplanetary discs around young stars
Anders Johansen (Lund University, Sweden)
Planets form in protoplanetary discs around young stars as dust and ice particles collide to form larger and larger bodies. I will present a coherent theory framework for the formation of planetary systems. Dust grows to pebbles by coagulation and deposition of volatile ices, but the continued growth to planetesimals is hampered by the poor sticking of mm-cm-sized pebbles. Planetesimals can nevertheless form by gravitational collapse of pebble clumps concentrated in the turbulent gas through the streaming instability. The subsequent growth initially occurs by planetesimal-planetesimal collisions, but the accretion rate of pebbles dominates the growth from 1000-km-sized protoplanets to form the solid cores of gas giants, ice giants and super-Earths. The high growth rates by pebble accretion allow planetary cores to start their growth in much more distant positions than their final orbits. The giant planets orbiting our Sun and other stars can therefore be formed in consistency with planetary migration.