Lonely stars born on a bridge between galaxies

Lonely stars born on a bridge between galaxies

• NEW SCIENTIST
• 02 April 2010

The Large Magellanic Cloud (pictured) likely stripped gas from its smaller neighbour, forming a bridge between them (Image: C. Smith/S. Points/MCELS Team/NOAO/AURA/NSF)

MOST stars are gregarious, grouping together by the billions in galaxies like our Milky Way. Now evidence is mounting that stars may form in between galaxies.

Vanessa McBride at the University of Southampton in the UK and her colleagues looked at X-rays arriving from the space between two nearby galaxies, the Large and Small Magellanic clouds. The energy spectrum and periodic fluctuations of the X-rays, recorded by the INTEGRAL satellite, suggest they are coming from young binary star systems in which a neutron star is stealing matter from its massive companion.

One such system was already known in a stream of gas called the Magellanic Bridge between the two galaxies. McBride identified two more and found tentative signs of three others (Monthly Notices of the Royal Astronomical Society, vol 403, p 709). The gas was probably stripped from the Small Magellanic Cloud by its larger neighbour's gravity, providing fuel for star formation.

The Magellanic Bridge is ideal for studying such violent interactions in detail because it is so near, says Nicolas Lehner of the University of Notre Dame in Indiana.