Reduction of chemical network: fractional ionization in protoplanetary disks

This web page contains supplementary data to the article D.A. Semenov, D.S. Wiebe, & Th. Henning "Reduction of chemical networks. II. Fractional ionisation in protoplanetary discs" (2004), A&A, 417, 93. It include all those reduced networks that are cited in this paper along with the "full" network and two files with the physical conditions and initial abundances. The "full" network is based on the UMIST95 database of chemical reactions and can be downloaded here.

As initial abundances, we adopted a set of molecular abundances computed for the conditions typical of dark molecular clouds (T=10 K, n_H=2000 cm^-3, t=10⁶ yrs) starting from the "low metal" abundances of Lee et al. (1996). This file can be found here.

We used the 1+1D disk model of P. D'Alessio et al. (1999) as a guide for the physical conditions thought to be encountered in T Tau protoplanetary disks. The disk is divided by 7 vertical and 11 radial grid slices. Then, we estimated temperature (T ), density (r ), intensity of the stellar (G₀) and interstellar UV radiation, extinction factors in vertical (A_V^IS) and radial (A_V^St) directions as well as X-ray (z_X) and cosmic ray (z_CR) ionization rates in all these 77 disk grid points. The corresponding files for 7 vertical slices can be downloaded here:

Finally, for each considered disk point, we isolated a reduced chemical network which governs the fractional ionization with better than 100% accuracy for the entire evolutionary time span 0.001 yrs<t<10⁶ yrs. All these reduced networks can be found in the following table:

Amount of species and reactions in each reduced network

ri/zi,j	0	1	2	3	4	5	6	7	8	9	10
1 AU	5x3	58x142	39x78	30x58	26x105	26x105	28x166	26x70	5x5	5x5	5x5
3 AU	13x14	60x102	62x142	62x218	115x308	20x85	19x77	39x173	31x84	17x46	17x46
10 AU	94x246	94x246	113x364	29x88	29x88	18x52	18x52	19x77	18x52	18x52	18x52
30 AU	18x40	18x40	18x40	18x40	18x40	19x77	17x46	17x46	17x46	17x46	17x46
100 AU	19x40	19x40	19x40	19x40	64x204	19x77	19x77	19x77	19x77	19x77	19x77
300 AU	19x40	19x40	19x40	19x40	96x407	19x77	25x170	19x77	19x77	19x77	19x77
370 AU	19x40	19x40	19x40	19x40	95x399	19x77	19x77	19x77	19x77	19x77	19x77

In addition to the individual reduced network, we combined from them a SIngle REduced Network for the whole disk (SIREN). This network includes 113 species involved in 518 reactions and allows to compute disk fractional ionization with reasonable accuracy of less than 100% for entire 1 Myr evolutionary time span and all disk locations but inner disk midplane. It can be downloaded here. The ratio between fractional ionizations computed with SIREN and "full" networks for t=10₆ yrs is presented below:

Note that all forementioned reduced networks are valid for the specified disk model and initial abundances!