| Description |
We propose to investigate the interstellar chemistry and physics of nitrogenthrough Herschel/HIFI observations of simple nitrogen-hydride moleculesincluding NH, NH2, NH3, and related ions. The nitrogen chemistry is still rather uncertain and we therefore propose to compare and contrast the abundances and ortho/para ratios of nitrogen hydrides in the diffuse interstellar gas to the dense cores of molecular clouds. This comparisoncan be done very efficiently by observing excited-state transitions in selected cores that have previously been used in the PRISMAS program as background sources for absorption measurements in the ground-state transitions. In this way, we will determine whether nitrogen chemistry is dominated by gas-phase reactions or by processes on surfaces of dust grains, and whether the dominant chemistry is different in differentparts of the interstellar medium. In summary, we propose HIFI observations of 5 transitions of simple nitrogen-bearing molecules in 8 sources, and 3 transitions in 2 sources. The total requested observing time is 26.2 hours. |
| Keywords |
Herschel Space Observatory data, ESA Herschel mission dataset, far-infrared astronomy observations, submillimeter astronomy data, infrared space telescope observations, PACS photometer data, PACS spectrometer data, SPIRE photometer data, SPIRE Fourier transform spectrometer data, HIFI heterodyne spectroscopy data, far-infrared spectroscopy dataset, submillimeter spectral line observations, cold universe observations dataset, star formation infrared data, molecular cloud far-infrared observations, interstellar medium spectroscopy data, protoplanetary disk infrared observations, galaxy evolution far-infrared data, dust emission submillimeter observations, cosmic infrared background measurements, extragalactic infrared survey data, calibrated level 2 data products, FITS files astronomy, spectral cubes far-infrared, flux-calibrated maps, continuum photometry data, spectral energy distribution measurements, ESA Herschel Science Archive data |
