# total_number¶

sbpy.activity.total_number(mol_data, aper, b)[source]

Equation relating number of molecules with column density, the aperture, and geometry given and accounting for photodissociation, derived from data provided. Feel free to use your own total number to calculate production rate or use this function with your own molecular data as long as you are aware of the needed data.

Parameters
integrated_lineQuantity

Integrated flux of emission line.

mol_datasbpy.data.phys
sbpy.data.phys object that contains AT LEAST the following data:
Transition frequency in MHz
Einstein Coefficient (1/s)
Beta: (Timescale (in s) * r^2 (in au))
Column Density in 1/m^2

The values above can either be given by the user or obtained from the functions einstein_coeff and beta_factor Keywords that can be used for these values are found under fieldnames documentation. We recommend the use of the JPL Molecular Spectral Catalog and the use of from_jplspec to obtain these values in order to maintain consistency. Yet, if you wish to use your own molecular data, it is possible. Make sure to inform yourself on the values needed for each function, their units, and their interchangeable keywords as part of the Phys data class.

Returns
total_number: astropy.units.Quantity

An astropy Quantity containing the total number of molecules within the aperture (Dimensionless)