Dancing galaxies form a monster in the cosmic dawn

Aug. 30 () –

Astronomers have discovered a pair of galaxies at the moment of their merger 12.8 billion years ago to form a monstrous galaxyone of the brightest types of objects in the Universe

Quasars are bright objects fueled by matter falling into a supermassive black hole at the center of a galaxy in the early Universe. The most widely accepted theory is that when two gas-rich galaxies merge to form a single, larger galaxy, the gravitational interaction of the two galaxies causes gas to fall toward the supermassive black hole in one or both galaxies, which causes quasar activity.

To test this theory, an international team of researchers led by Takuma Izumi used the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope to study the first known pair of nearby quasars. This pair was discovered by Yoshiki Matsuoka of Ehime University in Japan in images taken by the Subaru telescope, according to a statement from ALMA.

Located in the direction of the constellation Virgo, this pair of quasars existed for the first 900 million years of the Universe. The pair is faint, indicating that the quasars are still in the early stages of their evolution. ALMA observations mapped the quasars’ host galaxies and showed that the galaxies are linked by a “bridge” of gas and dust. This indicates that the two galaxies are, in fact, merging.

The ALMA observations also allowed the team to measure the amount of gas, the material for new star formation. The team found that the two galaxies are very rich in gas, suggesting that in addition to more vigorous quasar activity in the future, the merger will also trigger a rapid increase in star formation, known as a “starburst.”

The combination of starburst activity and vigorous quasar activity is expected to create A super bright object in the early Universe known as a monster galaxy.