Supernovas May Form Dust and Dirt Flowing through Galaxies: ESO

An explanation for the dirty, dusky appearance of galaxies in interstellar space may be revealed by new observations from the ALMA telescope, which captured for the first time the remnants of a recent supernova brimming with freshly formed dust.

A paper detailing the observations is to be published in the Astrophysical Journal Letters, according to the European Southern Observatory (ESO).

The ALMA (Atacama Large Millimeter/submillimeter Array) telescope's measurements provide some of the first direct evidence of a supernova's dust-making capabilities, which gives credence to the hypothesis that supernovae are a primary source of galactic dust.

"We have found a remarkably large dust mass concentrated in the central part of the ejecta from a relatively young and nearby supernova," Remy Indebetouw, an astronomer at the National Radio Astronomy Observatory (NRAO) and the University of Virginia, said in a statement from the ESO. "This is the first time we've been able to really image where the dust has formed, which is important in understanding the evolution of galaxies."

ALMA trained its eye on supernova 1987A, which is about 160,000 light‐years from Earth in the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way.

As gas from SN 1987A cooled after the initial supernova explosion, it is believed that large amounts of dust formed as atoms of oxygen, carbon and silicon bonded together in the cold central regions of the dead star. This was never confirmed, however, because infrared observations made in the first 500 days after the explosion detected only a small amount of dust.

But with the highly sensitive calibration of ALMA, astronomers were able to get a better picture of the SN 1987A.

"With ALMA's unprecedented resolution and sensitivity, the research team was able to image the far more abundant cold dust, which glows brightly in millimeter and millimeter light," the ESO said in a statement. "The astronomers estimate that the remnant now contains about 25 percent the mass of the Sun in newly formed dust. They also found that significant amounts of carbon monoxide and silicon monoxide have formed."

Indebetouw said that SN 1987A is in a special place that makes its study ideal because it has not mixed in with its surrounding environment, so observations of the supernova now reveal evidence of what has been made in the supernova's wake.

"The new ALMA results, which are the first of their kind, reveal a supernova remnant chock full of material that simply did not exist a few decades ago," he said.

"Really early galaxies are incredibly dusty and this dust plays a major role in the evolution of galaxies," said Mikako Matsuura of University College London, UK. "Today we know dust can be created in several ways, but in the early Universe most of it must have come from supernovae. We finally have direct evidence to support that theory."