title dense phase zeta persei cloud
c
c density and abundances ==========
c density of dense phase from Table 2 of Le Petit paper ========
hden 4.3
c 
c abundandces from Table 1 of Le Petit paper ==========
element carbon abundance 0.000132 linear
element helium abundance 0.10 linear
element oxygen abundance 0.00032 linear
element nitrogen abundance 0.000075 linear
element sulphur abundance 0.0000186 linear
element silicon abundance 0.000029 linear
c set abundance of all other elements to zero ====================
element copper off
element magnesium off
element manganese off
element sodium off
element chlorine off
element vanadium off
element potassium off
element phosphorous off
element calcium off
element iron off
element zinc off
element neon off
element argon off
element fluorine off
element aluminum off
element boron off
element lithium off
element beryllium off
element scandium off
element nickel off
element titanium off
element chromium off
element cobalt off
c do not use Federman rates for this model ==============
set federman chemistry off
c use standard ism grain size distribution ============
grains ism 
c 
c command controlling the continuum, for this model is Draine 1978 field ====
table draine 0.5 linear
c make sure no H-ioinizing radiation strikes the cloud
extinguish 24 
c 
c fix the temperature to 20 K =============
constant temperature 20
c stop at a radius of 4.3e-4 parsecs ============ 
stop thickness 0.00043 parsecs linear
c Le Petit model does not consider ices, so turn this off ============
no grain molecules
c turn on cosmic rays =========
cosmic rays background
c Set cosmic ray ionization rate to Table 2 of Le Petit paper ========
set csupra -15.6
c Allow calculation to go extend into cold environment ============
stop temperature linear 3
c 
c commands controlling output ============
save performance "pdr_dense_persei.per"
save overview "pdr_dense_persei.ovr"
save dr "pdr_dense_persei.dr"
save molecules "pdr_dense_persei.mol"
save heating "pdr_dense_persei.het"
save cooling "pdr_dense_persei.col"
save monitors "pdr_dense_persei.asr"
c 
c commands giving the monitors ==========
monitor C2 column density 12.908 error 0.2 
monitor C3 column density 11.866 error 0.2
monitor hydrogen 1 temperature 20K 
// 
// >>chng 06 mar 02, from 13.30 to 13.46, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
monitor CO column density 13.46 error 0.2
// 
// >>chng 08 dec 08, from 300 to 226, upper limit -> equals (r2515)
// >>chng 09 jun 15, from 226 to 244, gradual approach to outer edge
// >>chng 11 nov 16, from 244 to 211, adjust newmole monitors
monitor nzone 211 error 0.01
//
// >>chng 08 dec 08, from 10 to 3.898, upper limit -> equals (r2515)
// >>chng 08 dec 13, from 3.898 to 5.628, merging newsolvers branch
// >>chng 09 jan 16, from 5.628 to 5.645, average of 10 runs
// >>chng 09 feb 24, from 5.645 to 5.54, botches due to r2763
// >>chng 09 jun 15, from 5.54 to 5.406, gradual approach to outer edge
// >>chng 09 jun 26, from 5.406 to 5.107, remove several dampers
// >>chng 11 nov 16, from 5.107 to 4.507, adjust newmole monitors
// >>chng 12 mar 07, from 4.507 to 4.619, renorm to r5961 results
// >>chng 12 jul 01, from 4.619 to 4.479, update Badnell DR to 13-electron iso sequence
monitor itrzn 4.479
//
c pdr_dense_persei.in
c class pdr
c ====================================

This is the dense phase model presented by LePetit, Roueff, and Herbst 
in order to reproduce C2 and C3 column densities observed along the line
of sight to zera persei.  This is our attempt at reproducing their calculation.
This is the dense molecular phase, not the phase that produces H3+ 

// >>refer	model	pdr	Le Petit, F., Roueff, E., & Herbst, E. 2004,
// >>refercon	A&A, 417, 993

If you do a thermal equilibrium calculation by removing the constant temperature
command the kinetic temperature will be about three times larger than
assumed in their paper.