column_density¶

Physics.Radiation.column_density(freq, TaDv, g_up, Aul)¶

Column density from an integrated spectral line

Given the line frequency, the integrated line intensity, the upper state degeneracy, and the Einstein A, returns the column density in cm**-2.

:param freq : line frequrncy in MHz :type freq : float

:param TaDv : integrated line intensity in K-km/s :type TaDv : float

:param g_up : upper state degeneracy :type g_up : int

:param Aul : Einstein A :type Aul : float