Colliding molecular clouds in head-on galaxy collisions

  title={Colliding molecular clouds in head-on galaxy collisions},
  author={J. Braine and Ute Lisenfeld and P.-A. Duc and Elias Brinks and Vassilis Charmandaris and St'ephane Leon},
  journal={Astronomy and Astrophysics},
We present further observations of molecular gas in head-on collisions of spiral galaxies, this time of the CO(J = 1 → 0) and CO(J = 2 → 1) lines in the UGC 813 - UGC 816 system. UGC 813/6 are only the second known example of head-on spiral-spiral collisions, the first example being the UGC 12914/5 pair. Strong CO emission is present in the bridge between UGC 813 and 816, unassociated with stellar emission, just as in UGC 12914/5. The CO emission from the UGC 813/6 bridge, not counting the… 

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