Astronomers discover 'ghost' galaxy near Milky Way

  • Astronomers discover 'ghost' galaxy near Milky Way

Astronomers discover 'ghost' galaxy near Milky Way

Astronomers have discovered an enormous "ghost" galaxy in the outskirts of the Milky Way. Scientists think that streams like this one are the cosmic debris leftover when small galaxies stray too close to the Milky Way. It is also characterised by low mass, meaning it is also low in density.

Scientists have published the discovery in the online pre-print site arXiv.

The ESA's Gaia mission has produced the richest star catalogue to date, including high-precision measurements of almost 1.7 billion stars and revealing previously unseen details of our home Galaxy. And Gaia picked out the S1 stream because its some 30,000 stars have a different chemical composition than those native to our galaxy.

A team of astronomers using the Gaia satellite have found a "ghost" galaxy haunting the outer edges of our own.

Dwarf galaxy stars are old and quite low in mass and metal.

Dozens of such streams have been found in the Milky Way. From this image, scientists were able to calculate the mass of the front cluster as 250 times greater than it should be, considering the combined mass of all the stars and planets and other "normal" matter inside it.

Adding heat to the outlandish apocalypse claims surfacing all around the internet, a team of astronomers has suggested that an incredibly fast dark matter hurricane will soon slam into the earth as it moves through the Milky Way.

The team of the researcher has measured the spectra of more than 100 red giant stars just before the Earth's motion around the Sun rendered the "ghost galaxy" unobservable for months.

They are yet to explain how Antlia 2 became so much extended in size. It is always at least 130,000 light-years away from Earth.

"RR Lyrae had been found in every known dwarf satellite, so when we found a group of them sitting above the Galactic disk, we weren't totally surprised", said co-author Dr. Vasily Belokurov, researcher at Cambridge's Institute of Astronomy.

Current theories of galaxy formation can not fully explain how a galaxy so large has so few stars. The researchers believe that the dwarf galaxy has so little mass because of the constant pull of the galactic tides of the Milky Way.

Alternatively, the properties of the elusive "dark matter", thought to keep galaxies together, might need to be re-thought.

The researchers said that now available to scholars detectors are unlikely to weakly interacting massive particles S1 (WIMP) or wimpy - hypothetical objects, which, according to some scientists, account for dark matter. Researchers from Universidad de Zaragoza, King's College London and the Institute of Astronomy in the United Kingdom have been studying a stellar stream left behind by a dwarf spheroidal galaxy that was devoured by the Milky Way aeons ago. "We are wondering whether this galaxy is just the tip of an iceberg, and the Milky Way is surrounded by a large population of almost invisible dwarfs similar to this one".