Formaldehyde (H_2_CO) is a reliable tracer to accurately measure the physical parameters of dense gas in star-forming regions. We aim to determine directly the kinetic temperature and spatial density with formaldehyde for the ~100 brightest ATLASGAL-selected clumps (the TOP100 sample) at 870um representing various evolutionary stages of high-mass star formation. Ten transitions (J=3-2 and 4-3) of ortho- and para-H2CO near 211, 218, 225, and 291GHz were observed with the Atacama Pathfinder EXperiment (APEX) 12m telescope.
Cone search capability for table J/A+A/611/A6/tablea1 (Source parameters)