From its origin at the center of a star to the edge, through the surrounding gas and dust in the distant galaxy, through the intergalactic medium, traveling billions of light years only to be... Show moreFrom its origin at the center of a star to the edge, through the surrounding gas and dust in the distant galaxy, through the intergalactic medium, traveling billions of light years only to be reflected by a mirror and captured by a detector; the little amount of light observed from galaxies in the early universe contains a wealth of historic information. This thesis concentrates on translating the luminosities and colors of distant galaxies to physical properties such as distance, mass, age of the stellar population, and dust content. Analyzing deep optical and infrared observations of distant (redshift z~2.5) galaxies, we learn that massive galaxies have on average redder colors than less massive galaxies, although simulations show that mass underestimates of star-forming galaxies are possible. Roughly half of the red galaxies at high redshift owe their color to an old, quiescent stellar population. The other half is still actively star-forming, but obscured by large columns of dust. The abundance of star-forming and quiescent galaxies is consistent with a model that assigns a key role to collisions between gas-rich disk galaxies involving quasar activity, and leaving red spheroids as remnants. However, this model does not reproduce the colors of dusty red galaxies. Show less
