Archive

Archive for February 16, 2012

Archaeology of Galaxies – The Dragon Clash

February 16, 2012 Leave a comment

Numerous collisions have probably affected the shape of galaxies, and perhaps, half of spiral galaxies have been formed this way during the last 9 billions years. Possibly this is the case for NGC5907, a spiral galaxy in the Dragon constellation. However this galaxy is almost bulgeless, while prominent and classical bulges are generally considered to be a signature of major mergers.

In fact NGC5907 has been observed with the deepest ever-made imagery, revealing a system of stellar currents forming gigantic loops in its surrounding halo. These phenomena have been intensively studied by a team of six scientists of the Observatoire de Paris, CNRS, Chinese Academy of Sciences, National Astronomical Observatories of China NAOC and Marseille Observatory. To reproduce them they have used several state of the art, hydrodynamical, and numerical simulations with particle numbers ranging from 200 000 to 6 millions. They succeeded in doing so after assuming that these gigantic loops were the relic of a gigantic collision between galaxies of similar sizes, which would have occurred 8 to 9 billion years ago.

Full Story: http://www.grandpublic.obspm.fr/Archaeology-of-galaxies-The-Dragon

Advertisements

NASA Events and Future Forum Mark 50 Years of Americans in Orbit

February 16, 2012 Leave a comment

Feb. 20 marks the 50th anniversary of the day in 1962 when U.S. Sen. John Glenn piloted his Friendship 7 spacecraft on the first U.S. orbital flight. In the next two weeks, NASA Television will broadcast a series of live events and special programming to commemorate 50 years of Americans in orbit, including the premiere of a new documentary and special interactive online features.

Full Story: http://www.nasa.gov/home/hqnews/2012/feb/HQ_M12-029_John_Glenn_TV.html