we propose to use the lws to obtain the complete fir spectra of gas surrounding seven ob stars in the ngc 6334 complex. our goal is to examine in detail the impact of the ultravliolet field strengths on its photodissociation regions (pdrs), the interfaces between the h ii regions and the ambient molecular medium. ngc 6334 provides a unique stellar laboratory to study pdrs because (1) it has at least seven well-separated ob stars, (2) the stellar spectral types encompass an enormous range in ultraviolet field strengths, (3) the stars all lie at the same distance within the same molecular cloud, and (4) the region is relatively nearby. the unsurpassed sensitivity of iso will allow us to detect a number of fir lines. the atomic fine structure lines are pdr diagnostics. the ionic lines provide a measure of the hardness of the uv field, h ii region densities, and element abundances. the molecular lines of h2o, co, oh, and nh3 probe the warm, dense molecular gas associated with the pdrs. these observations will allow for the first time a direct comparison of pdrs from single stars of known uv field strengths. we will compare our new fir data with our molecular line, radio and fir continuum data to obtain a complete census of the ism in all of its phases to determine empirically the effect of uv field strength on the surrounding ambient gas and to test the predictions theoretical pdr models.
Instrument
LWS01
Temporal Coverage
1996-03-20T04:23:21Z/1996-03-20T07:16:55Z
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, JACKSON et al., 1999, 'PHOTODISSOCIATED GAS IN THE NGC 6334 COMPLEX: THE INFLUENCE OF UV FIELD STRENGTH', 1.0, European Space Agency, https://doi.org/10.5270/esa-xendzy7
