/home66/gary/public_html/cloudy/c08_branch/source/rt_line_one_tauinc.cpp

Go to the documentation of this file.

/* This file is part of Cloudy and is copyright (C)1978-2008 by Gary J. Ferland and
 * others.  For conditions of distribution and use see copyright notice in license.txt */
/*RT_line_one_tauinc increment optical depths for all heavy element lines, zone by zone,
 * mainly called by RT_tau_inc, but also by FeII */
#include "cddefines.h"
#include "doppvel.h"
#include "geometry.h"
#include "rfield.h"
#include "radius.h"
#include "wind.h"
#include "rt.h"

void RT_line_one_tauinc(transition * t ,
        /* following four are flags to generate info if some species has extreme maser */
        long int maser_flag_species,
        long int maser_flag_ion,
        long int maser_flag_hi,
        long int maser_flag_lo )

{
        DEBUG_ENTRY( "RT_line_one_tauinc()" );

        /* routine increments optical depths for static or expanding atmosphere */

        /* this is line center frequency, including bulk motion of gas */
        long int ipLineCenter = t->Emis->ipFine + rfield.ipFineConVelShift;
        double OpacityEffective, EffectiveThickness;
        realnum dTau_total;

        /* find line center opacity - use fine opacity if array indices are OK */
        if( t->Emis->ipFine>=0 && ipLineCenter>0 && ipLineCenter<rfield.nfine && rfield.lgOpacityFine )
        {
                /* use fine opacities fine grid fine mesh to get optical depth 
                 * to continuum source */
                /* total line center optical depth, all overlapping lines included */
                OpacityEffective = rfield.fine_opac_zone[ipLineCenter];
        }
        else
        {
                OpacityEffective = t->Emis->PopOpc * t->Emis->opacity / DoppVel.doppler[ t->Hi->nelem -1];
        }

        /* use cumulated fine optical depth for both d-critical and static, 
         * for d-critical speeds are only roughly sonic
         * optical depth is computed including velocity shift */
        if( wind.windv <= 0. )
        {
                /* static and negative velocity solutions */

                EffectiveThickness = radius.drad_x_fillfac;
                dTau_total = (realnum)(OpacityEffective * EffectiveThickness);
                
                t->Emis->TauIn += dTau_total;
                t->Emis->TauCon += dTau_total;

        }

        else
        {
                /* this is effective length scale for Sobolev or LVG approximation.
                 * This is equation 3 of
                 * >>refer      RT      wind    Castor, J.I., Abbott, D.C., & Klein, R.I., 1975, ApJ, 195, 157
                 */

                /* dv/dr (s-1), equal to dv/dt / v */
                realnum dvdr = fabs(wind.AccelTot) / wind.windv;
                /* depth (cm) over which wind accelerates by one velocity width
                 * include filling factor */
                EffectiveThickness = DoppVel.doppler[ t->Hi->nelem -1] / SDIV(dvdr) *
                        geometry.FillFac;

                /* min2 is to not let the physical scale exceed the current depth */
                EffectiveThickness = MIN2( radius.depth, EffectiveThickness );
                dTau_total = (realnum)(OpacityEffective * EffectiveThickness);
                
                t->Emis->TauIn = dTau_total;
                t->Emis->TauCon = dTau_total;
                t->Emis->TauTot = dTau_total;
        }

        /* keep track of any masers */
        if( dTau_total < rt.dTauMase )
        {
                rt.dTauMase = dTau_total;
                rt.mas_species = maser_flag_species;
                rt.mas_ion = maser_flag_ion;
                rt.mas_hi = maser_flag_hi;
                rt.mas_lo = maser_flag_lo;
                if( rt.dTauMase < -1. )
                        rt.lgMaserCapHit = true;
        }

        return;
}

---