The specter of the galaxy

A group of international astronomers have identified giant star streams in the periphery of two nearby spiral galaxies. For the first time, they obtained a panoramic view of an example of galactic "carnivores" similar to what happened to the Sagittarius dwarf galaxy near the Milky Way.

The discovery of this vast star fossil confirms the prediction of the cold dark matter model of cosmology, which suggests that today's giant spiral galaxies are formed by the merger of two small crystals. than.

The first fragmentary structure in these two structures surrounding the galaxy NGC 5907, located 40 million light-years from Earth and formed from the destruction of one of its two satellite dwarf galaxies, lies that's at least 4000 light years. According to the research team, dwarf galaxies have lost a greater part of their mass in star formation, constellations and dark matter . All of this is scattered around the orbit, forming a cross-chain of galactic fossils spreading in excess of 150,000 light-years in diameter.

David Martinez, a researcher at the Instituto de Astrofísica de Canarias (IAC), said the team leader observed: 'Our results provide new insights into spectacular phenomena that occur around galaxies. This twist and show the halo that contains fossil dwarf galaxies, thus providing us with a unique opportunity to study the final stages in the process of merging galaxies like ours. '

Photo of the star tidal currents surrounding the spiral galaxy NGC 5907 taken with amateur robot telescopes in the mountains of New Mexico . (Photo: R. Jay Gabany)

The search of astronomers has not yet been able to determine the main body of 'swallowed' galaxies , leading them to conclude that until now they have been completely destroyed. 'These star lines are very difficult to detect and have very low star density. It was this that brought the ghost to it. Therefore, regarding the dwarf galaxy's death, they can be seen as ghosts of lost galaxies. '

The group also discovered a giant but thin, hook-shaped star in the galaxy NGC 4013, about 50 million light-years from Ursa Major. Its translucent tail lasts more than 80,000 light-years from the nucleus and contains old stars lacking metal. Although its 3-dimensional geometry is unknown, it has a structure very similar to the Monoceros line, a star around the Milky Way formed through the destruction of a dwarf galaxy 3 million years ago.

Jorge Peñarrubia is a theoretical astrophysicist at Victoria University (Canada) and the team specializes in simulating stellar lines. According to Peñarrubia, 'assembling theoretical models into stellar lines allows us to reconstruct their history and describe one of the most mysterious and controversial elements in the universe: dark matter.'

The role of space photographers

The research team had to rely on the help of aerospace photographer R. Jay Gabany to detect and trace the stars. Marinez appreciated his contribution and said 'this is a fact that emphasizes the great contribution of amateurs.'

For many years, R. Jay Gabany has obtained color photographs of spectacular deep blue skies with small robot telescopes in New Mexico in Australia. His photo has been published in the most famous astronomical magazines in the world. His effort for this project demonstrates the potential of amateur astronomers to contribute to the 21st century astronomy. Together with new technology, they can participate in competitive science projects. High at international level.