Cosmic-ray induced photodissociation and ionisation rates

The calculations made here of photodissociation and ionisation rate of atoms and molecules when exposed to cosmic-ray induced ultraviolet radiation are described in Heays et al. 2017. A description of the cosmic-ray induced UV flux used is given by Gredel et al. 1987 and 1989. Some assumptions made here are as follows

Some special calculations were made for N2 and CO and a broader set of conditions by Heays et al. 2014.

Click on a link below to get rates for that atom or molecule.

Al AlH C C2 C2H C2H- C2H2 C2H3
C2H4 C2H5 C2H5OH C2H6 C3 C3H3 C3H7OH C4H-
C6H- CH CH+ CH2 CH2+ CH3 CH3CHO CH3OCH3
CH3OCHO CH3CN CH3NH2 CH3OH CH3SH CH4 CH4+ CN
CO CO+ CO2 CS CS2 Ca Ca+ Cl
Co Cr Fe H H- H2 H2+ H2CO
H2CS H2O H2O2 H2S H3+ HC3H HC3N HCN
HCO HCO+ HCOOH HCl HCl+ HF HNC HNCO
HO2 K Li LiH Mg MgH Mn N
N2 N2O NH NH+ NH2 NH2CHO NH3 NO
NO2 Na NaCl NaH Ni O O2 O2+
O3 OCS OH OH+ P PH PH+ Rb
S S2 SH SH+ SO SO2 Si SiH
SiH+ SiO Ti Zn c-C3H c-C3H2 l-C3H l-C3H2
l-C4 l-C4H l-C5H

Tabulated rates for all atoms and molecules

[Download all rates in a csv file.]

In units per second (s-1).

Uncertainties are estimated from the known or approximate uncertainties of the measured and experimental cross sections compiled for each atom or molecule. These are estimated over the wavelength ranges relevant to cosmic ray generated radiation (80 to 150 nm). These are categorised as follows:

Species Photodissociation Photoionisation Uncertainty
Al — 2.50e-13 B
AlH 5.44e-15 1.50e-14 C
C — 2.60e-14 B
C2 1.83e-14 2.06e-14 B
C2H 1.11e-13 4.09e-14 C
C2H- — 1.32e-13 A+
C2H2 3.54e-13 3.83e-14 B
C2H3 4.81e-14 2.09e-13 C
C2H4 3.46e-13 2.84e-14 C
C2H5 6.26e-14 4.19e-14 A+
C2H5OH 2.65e-13 3.77e-14 B
C2H6 2.06e-13 1.78e-14 A
C3 6.88e-13 8.93e-15 C
C3H3 8.62e-15 1.79e-13 A+
C3H7OH 4.58e-13 5.93e-14 B
C4H- — 1.09e-13 A+
C6H- — 6.59e-14 A+
CH 1.08e-13 1.74e-14 C
CH+ 2.16e-14 — B
CH2 2.90e-14 — C
CH2+ 8.88e-15 — B
CH3 2.83e-14 3.79e-14 B
CH3CHO 2.24e-13 7.28e-14 A
CH3OCH3 1.76e-13 1.35e-13 A+
CH3OCHO 2.61e-13 2.24e-14 A+
CH3CN 2.57e-13 9.75e-15 B
CH3NH2 4.50e-14 1.79e-13 B
CH3OH 1.60e-13 2.41e-14 B
CH3SH 2.75e-13 2.03e-13 A
CH4 1.53e-13 2.24e-15 B
CH4+ 2.68e-14 — B
CN 4.51e-14 8.31e-16 B
CO 9.92e-15 1.59e-15 B
CO+ 7.73e-15 — B
CO2 6.56e-14 1.32e-15 B
CS 1.51e-13 7.63e-15 A+
CS2 5.49e-13 3.11e-14 A
Ca — 2.71e-14 B
Ca+ — 1.54e-16 B
Cl — 4.73e-15 B
Co — 6.04e-15 B
Cr — 1.20e-13 B
Fe — 4.81e-14 B
H — 4.08e-16 B
H- — 1.28e-13 B
H2 2.47e-15 5.81e-22 B
H2+ 6.08e-14 — B
H2CO 1.32e-13 2.93e-14 B
H2CS 2.05e-13 1.64e-13 B
H2O 1.02e-13 2.32e-15 B
H2O2 8.28e-14 1.85e-14 B
H2S 3.35e-13 6.22e-14 A
H3+ 2.33e-17 — A
HC3H 1.05e-13 2.19e-13 B
HC3N 5.95e-13 1.64e-14 B
HCN 1.98e-13 1.42e-15 B
HCO 5.29e-14 8.16e-14 A
HCO+ 3.35e-16 — B
HCOOH 2.04e-13 2.05e-14 A+
HCl 1.51e-13 4.64e-15 B
HCl+ 9.66e-15 0.00e+00 C
HF 1.84e-14 5.20e-24 A
HNC 1.43e-13 1.49e-14 B
HNCO 2.66e-13 7.43e-15 A
HO2 1.89e-14 5.58e-15 A
K — 3.37e-15 B
Li — 2.55e-14 B
LiH 6.17e-14 — B
Mg — 1.12e-14 B
MgH 2.54e-14 — C
Mn — 4.90e-15 B
N — 7.34e-17 B
N2 1.15e-14 1.50e-21 B
N2O 1.39e-13 9.89e-15 B
NH 3.69e-14 7.10e-16 B
NH+ 2.25e-15 — C
NH2 7.15e-14 6.31e-15 A
NH2CHO 2.95e-13 4.06e-14 B
NH3 1.08e-13 2.17e-14 B
NO 2.99e-14 2.37e-14 B
NO2 1.05e-13 1.09e-14 B
Na — 1.29e-15 B
NaCl 1.81e-14 — C
NaH 9.27e-14 — B
Ni — 1.40e-14 B
O — 2.70e-16 B
O2 7.56e-14 3.08e-15 B
O2+ 6.97e-15 — B
O3 1.49e-13 3.15e-15 B
OCS 5.23e-13 5.58e-14 A
OH 5.34e-14 1.65e-15 A+
OH+ 8.57e-16 — B
P — 1.46e-13 C
PH 7.24e-14 — C
PH+ 8.98e-15 — C
Rb — 2.28e-15 B
S — 7.91e-14 B
S2 1.29e-14 3.01e-13 B
SH 1.07e-13 1.00e-13 A+
SH+ 4.60e-14 0.00e+00 C
SO 5.54e-13 4.54e-14 C
SO2 2.70e-13 1.05e-14 A
Si — 4.16e-13 B
SiH 6.18e-14 4.97e-13 B
SiH+ 1.23e-13 — B
SiO 8.92e-14 — B
Ti — 2.35e-14 C
Zn — 1.98e-14 B
c-C3H 4.85e-14 1.65e-13 B
c-C3H2 6.87e-14 2.03e-13 B
l-C3H 2.98e-13 1.63e-13 B
l-C3H2 3.35e-13 — B
l-C4 1.78e-13 — B
l-C4H 6.08e-13 — B
l-C5H 1.72e-14 — B