Gigantic Explosions Buried in Galaxy Dust Mapped by ALMA

For the first time ever, astronomers have managed to directly map out the molecular gas and dust in the host galaxies of the most massive explosions in the galaxies. Using the Atacama Large Millimeter/submillimeter Array (ALMA), scientists have examined and learned a little bit more about gamma-ray bursts (GRBs).

Gamma-ray bursts are intense bursts of extremely high galaxy that are observed in distant galaxies. They're actually the brightest explosive phenomenon in the universe. The ones that last more than a few seconds, called long-duration gamma-ray bursts (LGRBs) are associated with supernova explosions, which occur at the end of a star's life.

These explosions are so powerful that in a matter of seconds, GRBs release as much energy as the sun will over the course of its entire lifetime. This explosion is usually followed by a fading emission, called an afterglow, which researchers can study more closely. Yet some GRBs actually seem to have no afterglow and are called dark bursts.

In order to learn a bit more about GRBs, the researchers used ALMA to detect the radio emission from molecular gas in two tark LGRB hosts-GRB 020819B and GRB 051022.

"We have been searching for molecular gas in GRB host galaxies for over ten years using various telescopes around the world," said Kotaro Kohno, one of the researchers, in a news release. "As a result of our hard work, we finally achieved a remarkable breakthrough using the power of ALMA. We are very excited with what we have achieved."

The researchers found a distribution of molecular gas and dust in GRB host galaxies. In fact, this is the first time that such a distribution among GRB host galaxies has been revealed. The findings reveal a bit more about GRBs and show astronomers a bit more about how these massive explosions occur in the universe.

The findings are published in the journal Nature.