Photo-electric heating options¶

For a detailed description on the default semi-analytic implementation of photo-electric heating in ProDiMo see Woitke+ (2009) Section 6.2.1.

In the following we describe briefly two other options that more self-consistently solve for the photo-electric heating rate.

We note some quick tests with a T Tauri disk model do not indicate huge changes in the photo-electric heating rate if one of those methods are activated.

Photo-electric heating from RT¶

.true.      ! dust_photoelectric_from_RT : compute the grain charge and photoelectric heating from RT

With this switch, the dust grain charge balance will be computed for every 10th dust size bin from the global grain size distribution, and from that a photo-electric heating rate is derived.

We note that this method dust not depend on any dust charge chemistry (i.e. it is not required to include dust as chemical species).

Photo-electric heating from RT for a typical grain size¶

To improve the code running speed, you can restrict to a typical grain size $\langle a \rangle$ ($\langle a^2 \rangle$) with the switch:

.true.  ! mean_dust_photoelectric_from_RT 

This switch can also be combined with charge_chemistry_v3 (see Dust charge chemistry), which requires to have dust as chemical species. In that case the photo-electric heating rate is calculated for a mean grain charge, which is determined by the chemistry. Also additional output file dust_charge.out is produced. The prodimo.pro script will find this extra output file and will generate a few more plots in out.ps. Namely,

• The minimum and maximum grain charge as a function of grain size
• Mean grain charge throughout the disk
• minimum grain charge
• Maximum grain charge

The physics in the calculation are best described in Weingartner and Draine 2001 (ApJS 134, 263)