Distant Galaxies

APEX Telescope Reveals Distant Galaxies Undergoing Most Intense Type of Star Formation

Astronomers have combined observations from the LABOCA camera on the ESO-operated 12-meter Atacama Pathfinder Experiment (APEX) telescope with measurements made with ESO’s Very Large Telescope, NASA’s Spitzer Space Telescope, and others, to look at the way that bright, distant galaxies are gathered together in groups or clusters. The more closely the galaxies are clustered, the more massive are their halos of dark matter, the invisible material that makes up the vast majority of a galaxy’s mass. The new results are the most accurate clustering measurements ever made for this type of galaxy.The galaxies are so distant that their light has taken around ten billion years to reach us, so we see them as they were about ten billion years ago. In these snapshots from the early Universe, the galaxies are undergoing the most intense type of star formation activity known, called a starburst. By measuring the masses of the dark matter halos around the galaxies, and using computer simulations to study how these halos grow over time, the astronomers found that these distant starburst galaxies from the early cosmos eventually become giant elliptical galaxies, the most massive galaxies in today’s Universe.Furthermore, the new observations indicate that the bright starbursts in these distant galaxies last for a mere 100 million years. The team’s results provide a possible explanation: at that stage in the history of the cosmos, the starburst galaxies are clustered in a very similar way to quasars, indicating that they are found in the same dark matter halos.