Milky Way is Eating Sagittarius

Some scientists said in late September that our Milky Way galaxy is gobbling up its galactic neighbor, Sagittarius, and have offered documentary proof of this continuing cosmic cannibalism.

Astronomers have mapped the Sagittarius galaxy to show in detail how its debris wraps around and pass through the Milky Way, which contains Earth.

On its way to oblivion, the dwarf Sagittarius -- which is about 10,000 times less massive than the Milky Way -- is getting stretched, torn apart and ultimately eaten, scientists at the University of Virginia and the University of Massachusetts reported.

The act of cannibalism had been obscured by stars and cosmic dust, but was revealed when astronomers looked for infrared radiation coming from stars known as M giants, which are common in Sagittarius but rare in the outer reaches of the Milky Way.

By focusing on these stars, the scientists said they were able to capture the totality of the Milky Way's meal, in a vision that makes it appear that our galaxy is slurping the stars of Sagittarius as if they were a stellar strand of spaghetti.

Before this work, astronomers had detected only a few scattered pieces of the disrupted Sagittarius dwarf. Even the existence of the dwarf galaxy Sagittarius was unknown until the heart of our nearest satellite galaxy was discovered in 1994.

The dwarf galaxy Sagittarius was so named because it is observed in the same direction of the ancient constellation Sagittarius, a handful of Milky Way stars that the Romans thought resembled an archer with bow and arrow. "Sagittarius" is Latin for "archer."

The study will be published in the December 20 issue of the Astrophysical Journal.

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Khorsheed.com – Oct 2003