several of the full lws spectra of ir bright galaxies observed to date are dominated by clear absorption and possible faint emission in a number of molecular species including oh, hd, and ch (or heh+). these spectra are indicative of very high column densities/extinction, as is also found by the sws instrument team (eg. lutz et al. 1996, a&a iso issue). this proposal is one of several follow-up proposals designed to verify and study the cloud conditions, chemistry, and column densities in a sample of bright galaxies. > here we request time for deep lws grating observations of the hd 112 um (j = 1-0), hd 56 um (j = 2-1) (for two galaxies), and ch 149 um lines in a small sample of bright galaxies in which we believe they are bright enough to be detected at the level seen in m82 and for which lws and sws spectra have been obtained. estimation of the molecular column densities toward these heavily obscurred galactic nuclei can be used to infer the column density of h_2 with minimum dependence on the gas metallicity, using the current estimates of the abundance of d/h.
Instrument
LWS01
Temporal Coverage
1997-08-17T07:24:38Z/1997-08-17T08:27:38Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, FISCHER et al., 1999, 'LWS GRATING OBSERVATIONS OF HD AND OTHER MOLECULES IN IR BRIGHT GALAXIES', 1.0, European Space Agency, https://doi.org/10.5270/esa-saywgjb
