# <== this is a comment # # the cloud is ionized by a nearby star cluster, NGC 6611. The brightest # star is the O3 - O5 V star W205 which is about 2kpc distant # McLeod+15 http://adsabs.harvard.edu/abs/2015MNRAS.450.1057M # # 50 000 K blackbody, roughly an O3 - O5 V star blackbody, T=4.87e4 K # the AGN3 Table 2.3 entry for O4 V Q(H) 49.70 # # RADIUS gives the separation between the star and the cloud. # units are log cm. The projected separation between star # and nebula is about 2 pc according to McLeod. This is # slightly more than 2 pc (log 2 pc 18.78 cm) radius 19 # # this is the log of the hydrogen density, cm-3 hden 3 # # use a standard set of H II region abundances, including grains abundances HII region # # not important in the H II region, # but will be critical when we # extend it to the PDR cosmic ray background # # cosmic microwave background at z=0 CMB # # we must iterate at least one time # to establish line optical depths iterate # we only want the output for the last iteration print last iteration # # # this will save the temperature and ionization of the cloud save overview "M16.ovr" last # # save the spectrum save continuum "M16.con" units microns last # # save emissivities of a few lines as a function of depth # to compare with HST Pillars of Creation image save line emissivity "M16.ems" last H 1 4861.33A O 1 6300.30A Blnd 3727.00A O 3 5006.84A end of lines # # a field of stars, or an empty line, ends the input parsed by Cloudy ******************************* I use the area after the input ends to save comments about the model. From McLeod+15: One of the prime examples of pillars in a massive star-forming region is the Pillars of Creation in the Eagle Nebula (M16), which can be seen as protruding from a molecular cloud into a vast H II region inflated by the 2–3 Myr old and ∼2 kpc distant (Hillenbrand et al. 1993) massive cluster NGC 6611, whose brightest and most massive object (the O3–O5 V star W205) lies – in projection – just short of 2 pc north-east of the Pillars. The Pillars can be divided into three main structures, all of them pointing towards the cluster stars of NGC 6611.