Delta på disputasen
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Delta på prøveforelesning - 21. januar kl. 10:15 (Aud. 209, Svein Rosselands Hus)
"Kilonovae and their relation to Gamma Ray Bursts"
Kreeringssammendrag
Denne avhandlingen er en studie av livssyklusen til interstellar gass i nærliggende galakser.
Basert på observasjoner utført av syv forskjellige teleskoper presenterer avhandlingen strammere grenser på flere aspekter ved kald stjernedannende gass, samt hvordan galaktiske vinder i dverggalakser oppfører seg.
Den presenterer også en ny teknikk for å kunne måle slike vinder i detalj når de oppstår i kaotiske galaksefusjoner.
Hovedfunn:
In this thesis, I investigated interstellar gas in nearby galaxies. The life cycle of this gas is known as the baryon cycle.
As interstellar gas cools down, it forms dense clouds that eventually collapse into stars. This dense molecular gas is of great interest to observers studying star formation and galaxy evolution. I studied the cold molecular gas in a large sample of local low-mass galaxies, to understand how their gas content scales with their mass and rate of star formation. The results showed that small galaxies in the local universe on average contain similar amounts of cold gas than their larger counterparts, but that they are slightly more efficient at turning it into stars.
The formation of stars and the growth of supermassive black holes release enormous amounts of energy, which can eject gas from the galaxy in the form of outflows. I searched for outflows in low-mass galaxies, finding that with sufficient spectral resolution, they are found very commonly in this population. Finally, I studied an outflow in a massive galaxy merger measuring tracers of molecular, atomic, and ionized gas that appears to be accelerated out to several kiloparsecs. I use a new technique to measure the mass of the molecular gas and dust in the outflow.