3 mm spectroscopic observations of massive star-forming regions with IRAM 30 m

Broad-band spectroscopic observations with high sensitivity provide an unbiased way to detect emissions of molecules in space. We present deep observations from 105.8 to 113.6 GHz toward 50 Galactic massive star-forming regions using the IRAM 30 m millimeter telescope, with noise levels ranging from 6 to 29 mK at frequency channel spacing of 195 kHz, which corresponds to ∼0.54 km s⁻¹ at 110 GHz. In total, 27 molecular species have been identified, of which 16 are complex organic molecules. The related parameters, such as peak temperature, integrated intensity, and line width of the identified molecular lines were obtained. The line widths of the chemically related molecules show strong positive correlations, suggesting they likely originate from similar gases within star-forming regions. This work highlights the fundamental properties of the detected molecular lines and offers a valuable dataset for further studies on the astrochemical evolution of molecules in massive star-forming cores.