Gas Evolution in the Early Universe Revealed with Keck
Over the past few decades, astronomers have studied the process of gas accretion that drives the formation of stars and galaxies within dark matter halos. People have established a theoretical paradigm, which envisions galaxies fed by cool ‘streams’ of gas, linked to the surrounding circumgalactic medium (CGM) and intergalactic medium (IGM) by a web of cosmic filaments. Despite the general agreement among theorists, fundamental questions are yet to be solved and tested empirically. Due to their extremely low densities, the emission of CGM and IGM are very faint with very low surface brightness. Fortunately, recent development of more advanced instrumentations allows astronomers to see the low-surface brightness IGM emission for the first time.
Read more...