Witnessing starbursts in young galaxies

On March 13, it was announced the most vigorous bursts of star birth in the cosmos took place much earlier than previously thought – results now published in a set of papers in Nature and the Astrophysical Journal.

As these findings are published, three of the scientists at the forefront of this research – including the lead researcher of the latest findings – offered their insights about what this reveals about the history of our universe, and how the Atacama Large Millimeter/submillimeter Array (ALMA) is providing a “zoom lens” into the early universe.

This includes their surprise at finding so many star-producing “dusty galaxies” at such a young time in the universe's development. “They were not in line with what you would expect from the well known population of radio sources,” said John Carlstrom, Deputy Director of the Kavli Institute for Cosmological Physics at the University of Chicago and leader of the 10-meter South Pole Telescope project. “This was the first clue we were onto something interesting. …It meant that they had escaped detection in the infrared surveys. No one had predicted that we would see such a luminous population of dusty galaxies so far back.”

Dan P. Marrone, Assistant Professor in the Department of Astronomy at the University of Arizona, also noted the results were possible even though ALMA itself is still incomplete. “With little more than a dozen antennas at ALMA, we were able to make very detailed images of these galaxies – and that was after just two minutes of observations per galaxy.” He added, “When ALMA is completed, the observations we obtained for this first study are just going to be trivial.”

Joaquin D. Vieira a member of the California Institute of Technology's Observational Cosmology Group, as well as leader of the group studying the galaxies discovered by the South Pole Telescope, looked forward. “[Now] we can dig deeper into the spectra of these galaxies to find out what they're made of; we can do chemistry with them,” he said. “Future studies also will help us answer other important questions, such as how they formed. Did they form through mergers, or through the slow accretion of gas? How many stellar generations reside in these galaxies?”

Read more at:
http://www.kavlifoundation.org/science-spotlights/kipc-hred-starburst-galaxies