New tidal debris from colliding galaxies discovered by astronomers

Washington, June 13 (ANI): Astronomers have announced the discovery of new tidal debris stripped away from colliding galaxies.

New debris images are of special interest since they show the full history of galaxy collisions and resultant starburst activities, which are important in 'growing' galaxies in the early Universe.

In this study, new tidal debris were found with 8.2-meter Subaru telescope on Mauna Kea, Hawaii, which is operated by the National Astronomical Observatory of Japan.

The international team took extremely deep exposures of archetypal colliding galaxies, including "the Antennae" galaxies in constellation Corvus, "Arp 220" in constellation Serpens and "Mrk 231" in constellation Big Dipper, and 10 additional objects.

Often seen in public media and textbooks, these galaxies are well-known galaxy collisions.

"We did not expect such enormous debris fields around these famous objects," said Dr. Jin Koda, Assistant Professor of Astronomy at Stony Brook University.

"For instance, the Antennae - the name came from its resemblance of insect 'antennae' - was discovered early in 18th century by William Herschel, and has been observed repeatedly since then," he added.

Colliding galaxies eventually merge, and become a single galaxy. When the orbit and rotation synchronize, galaxies merge quickly.

New tidal tails therefore indicate the quick merging, which could be the trigger of starburst activities in Ultra Luminous Infrared Galaxy (ULIRG).

Further studies and detailed comparison with theoretical model may reveal the process of galaxy formation and starbursts activities in the early Universe.

"Arp 220 is the most famous ULIRG," said Dr. Taniguchi, who is Professor of Ehime University in Japan. "ULIRGs are very likely the dominant mode of cosmic star formation in the early Universe, and Arp 220 is the key object to understand starburst activities in ULIRGs," he added.

"The new images allow us to fully chart the orbital paths of the colliding galaxies before they merge, thus turning back the clock on each merging system," said Dr. Scoville, the Francis L. Moseley professor of astronomy at Caltech.

"New tidal debris are of significant importance since they put significant constrains on the orbit and history of the galactic collisions," said Dr. Koda. (ANI)