Broadband analysis techniques for Herschel/HIFI spectral surveys of
  chemically rich star-forming regions
  The Heterodyne Instrument for the Far Infrared (HIFI) aboard the Herschel
Space Observatory has acquired high-resolution broadband molecular spectra of
star-forming regions in a wavelength range that is mostly inaccessible from
ground-based astronomical observatories. These spectral surveys provide new
insight into the chemical composition and physical properties of molecular
clouds. In this manuscript, we present initial results from the HIFI spectral
survey of the Sagittarius B2(N) molecular cloud, which contains spectral
features assigned to at least 40 different molecules in a range of physical
environments. While extensive line blending is observed due to the chemical
complexity of this region, reliable molecular line identifications can be made,
down to the noise floor, due to the large number of transitions detected for
each species in the 1.2 THz survey bandwidth. This allows for the extraction of
new weakly emitting species from the line forest. These HIFI surveys will be an
invaluable archival resource for future investigations into interstellar
chemistry.
