Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers find nearest galaxy to Milky Way

04.11.2003


An international team of astronomers from France, Italy, the UK and Australia has found a previously unknown galaxy colliding with our own Milky Way. This newly-discovered galaxy takes the record for the nearest galaxy to the centre of the Milky Way.


The tidal forces of the Milky Way slowly pull apart the Canis Major dwarf galaxy (shown here in red). The stars ripped off in this fashion, surround the galaxy in a vast ring.



Called the Canis Major dwarf galaxy after the constellation in which it lies, it is about 25000 light years away from the solar system and 42000 light years from the centre of the Milky Way. This is closer than the Sagittarius dwarf galaxy, discovered in 1994, which is also colliding with the Milky Way. The discovery shows that the Milky Way is building up its own disk by absorbing small satellite galaxies. The research is to be published in the Monthly Notices of the Royal Astronomical Society within the next few weeks.

The discovery of the Canis Major dwarf was made possible by a recent survey of the sky in infrared light (the Two-Micron All Sky Survey or "2MASS"), which has allowed astronomers to look beyond the clouds of dust in the disk of the Milky Way. Until now, the dwarf galaxy lay undetected behind the dense disk. "It’s like putting on infrared night-vision goggles," says team-member Dr Rodrigo Ibata of Strasbourg Observatory. "We are now able to study a part of the Milky Way that has been previously out of sight".


The new dwarf galaxy was detected by its M-giant stars – cool, red stars that shine especially brightly in infrared light. "We have used these rare M-giant stars as beacons to trace out the shape and location of the new galaxy because its numerous other stars are too faint for us to see," explains Nicolas Martin, also of Strasbourg Observatory. "They are particularly useful stars as we can measure their distances, and so map out the three-dimensional structure of distant regions of the Milky Way disk." In this way, the astronomers found the main dismembered corpse of the dwarf galaxy in Canis Major and long trails of stars leading back to it. It seems that streams of stars pulled out of the cannibalised Canis Major galaxy not only contribute to the outer reaches of the Milky Way’s disk, but may also pass close to the Sun.

Astronomers currently believe that large galaxies like the Milky Way grew to their present majestic proportions by consuming their smaller galactic neighbours. They have found that cannibalised galaxies add stars to the vast haloes around large galaxies. However, until now, they did not appreciate that even the disks of galaxies can grow in this fashion. Computer simulations show that the Milky Way has been taking stars from the Canis Major dwarf and adding them to its own disk - and will continue to do so.

"On galactic scales, the Canis Major dwarf galaxy is a lightweight of about only one billion Suns," said Dr. Michele Bellazzini of Bologna Observatory. "This small galaxy is unlikely to hold together much longer. It is being pushed and pulled by the colossal gravity of our Milky Way, which has been progressively stealing its stars and pulling it apart." Some remnants of the Canis Major dwarf form a ring around the disk of the Milky Way.

"The Canis Major dwarf galaxy may have added up to 1% more mass to our Galaxy," said Dr Geraint Lewis of the University of Sydney. "This is also an important discovery because it highlights that the Milky Way is not in its middle age - it is still forming." "Past interactions of the sort we are seeing here could be responsible for some of the exquisite detail we see today in the structure of the Galaxy," says Dr Michael Irwin of the University of Cambridge.

Dr Rodrigo Ibata | alfa
Further information:
http://astro.u-strasbg.fr/images_ri/canm-e.html

More articles from Physics and Astronomy:

nachricht One-way roads for spin currents
23.05.2018 | Singapore University of Technology and Design

nachricht Tunable diamond string may hold key to quantum memory
23.05.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Research reveals how order first appears in liquid crystals

23.05.2018 | Life Sciences

Space-like gravity weakens biochemical signals in muscle formation

23.05.2018 | Life Sciences

NIST puts the optical microscope under the microscope to achieve atomic accuracy

23.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>