Gas molecular y formación estelar en galaxias enanas de marea

Tidal Dwarf Galaxies (TDGs) are created during a violent interaction of galaxies containing at least one spiral. Atomic hydrogen is torn off a spiral and star formation takes place in this gas which accumulates at the ends of tidal tails.
TDGs typically contain two main stellar components: young stars recently formed by collapse of expelled HI clouds, and an older stellar population, at least 1 Gyr old, which was pulled out from the disk of the parent galaxies. Their overall gaseous and stellar properties range between those of classical dwarf irregulars and blue compact dwarf galaxies, with the exception of their metallicity which is higher - typical of the outer disk of a spiral. TDGs allow us to observe the process of galaxy formation and evolution similar to what occured in the very early universe but in very local objectswhich can be studied with a sensitivity and a resolution unimaginable ofr high-redshift sources.
In the talk I will present observations of carbon monoxide (CO) in a sample of TDGs which allow to study the cool interstellar medium, star formation and the dark matter content of these objects.