| NGC 4261: An elliptical galaxy about 100 million 
      light years from Earth. 
 
 Caption: Chandra's image of NGC 4261 reveals dozens 
      of black holes and neutron stars strung out across tens of thousands of 
      light years like beads on a necklace. This spectacular structure, which 
      is not apparent from the optical image of the galaxy, is thought to have 
      been caused by a collision between galaxies a few billion years ago. As 
      a smaller galaxy was captured and pulled apart by the gravitational tidal 
      forces of NGC 4261, large streams of gas were pulled out into long tidal 
      tails. Shock waves in the tidal tails triggered the formation of large numbers 
      of massive stars, which eventually evolved into X-ray emitting neutron stars 
      and black holes. This image shows that X-ray observations may be the best 
      way to identify the ancient remains of mergers between galaxies.
 
 Scale: Each panel is 237 x 290 arcsec.
 
 Chandra X-ray Observatory ACIS Image
 
 
 
                  
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