Laboratory Measurements in Support of Astronomical Observations: Rotational Spectroscopy up the THz Region

The identification of a large variety of chemical compounds in space as well as planetary atmospheres has been made possible through the spectral signatures of astronomical bodies. For their interpretation, laboratory measurements are essential and rotational spectroscopy plays a leading role. Recent missions, such as the Herschel Space Observatory and the Stratospheric Observatory for Infrared Astronomy (SOFIA), have pointed out the need for precise and accurate frequency measurements and spectroscopic parameters in the submillimeter-wave range. The higher spectral resolution that can be exploited by the Atacama Large Millimeter Array (ALMA) is expected to play a key role in the detection of complex species as well as rare isotopologues. In the present contribution, the millimeter-/submillimeter-wave spectrometer working at the University of Bologna and its applications in the field of astronomical observations are presented. The focus is here on the accuracy of the retrieved transition frequencies of neutral as well as ionic species.