Molecular Gas in the Intergalactic Medium of Stephan's Quintet

Stephan’s Quintet (SQ) is a Hickson Compact Group well known for its complex dynamical and star formation history and its rich intergalactic medium (IGM). In order to study the extent, origin and fate of the intergalactic molecular gas and its relation to the formation of stars outside galaxies and Tidal Dwarf Galaxies (TDGs), we mapped with the IRAM 30 m antenna carbon monoxide (CO) towards several regions of the IGM in SQ. In two star forming regions (SQ A and B) we detected unusually large amounts of molecular gas (3.1 × 109 M⊙ and 7 × 108 M⊙, respectively), covering an extended area (between 15 and 25 kpc). In both regions the CO clouds have different properties and may be of a distinct nature.