Abstract 

  The Galactic Center is the closest region in which we can study star formation under extreme physical conditions like those sometimes encountered in high-redshift galaxies. We have mapped the inner 300 pc of the Central Molecular Zone (CMZ) in temperature sensitive molecular tracers to determine what is driving the heating and to find out in what way these tracers are themselves dependent on environmental conditions.  

  Maps of kinetic temperature are presented and compared with those of the dust. Potential heating mechanisms, like mechanical heating, UV irradiation (Photon Dominated Regions, PDRs), X-ray irradiation (X-ray Dominated Regions, XDRs), and cosmic ray irradiation (Cosmic Ray Dominated Regions, CRDRs) are introduced and a most likely scenario is identified. As an addendum, recently found new maser lines are also addressed.