Number of molecules required to produce an observed emission flux for a particular molecular species. If flux has units of ergs/cm²/s, then the standard form of the fluorescence efficiency, luminosity per molecule, i.e. L/N, is needed (having units of ergs/s/molecule). This is what we provide here, both normalized to 1 AU, and again scaled by r^-2 to the heliocentric distance requested.

We, along with many researchers, use the generic term "g-factor" as a shorter form of "fluorescence efficiency"; note, however, that true g-factors are defined as having units of photons/s/molecule.

Further details regarding the L/N values for each species can be found in A'Hearn et al. (1995, Icarus 118, 223-270); however, both NH and CN have been updated as of November 2009. In brief:

• C₂: single value for Δv=0 band sequence with a band head near 5160 Angstroms; scaled by r^-2.
• C₃: single value for the C₃ band complex which peaks near 4030 Angstroms and extends from 3300 to 4400 Anstroms; scaled by r^-2.
• OH: value of the 0-0 band centered near 3090 Angstroms varies with heliocentric velocity and whether or not the lambda-doublet ground state is quenched (unquenched values are given here); scaled by r^-2. [From Schleicher & A'Hearn 1988, ApJ 331, 1058-1077.]
• NH: value of the Δv=0 band sequence centered near 3360 Angstroms varies both with heliocentric velocity and with r (due to the strong change in the number of rotational levels populated with r). A 2-D table is scaled to 1 AU and double interpolated, then scaled by r^-2. [Based on extended version of Meier et al. 1998, Icarus 136, 268-279.]
• CN: value of the Δv=0 band sequence with a band head near 3885 Angstroms varies both with heliocentric velocity and with r (due to the strong change in the number of rotational levels populated with r). A 2-D table is scaled to 1 AU and double interpolated, then scaled by r^-2. [From Schleicher 2009, submitted to AJ.]