[SCIDB-97] spectrum viewer: allow users to change flux units

Fri, 4 Dec 2020 11:41:24 +0000

Allow users to change flux units. Most freuqnely used ways to represent spectral fluxes will be f_lambda, f_nu, and AB magnitude. In cgs,

f_lambda [erg/s/cm2/A]

f_nu [erg/s/cm2/Hz]

These two are related to each other by

lambda * f_lambda = nu * f_nu

(recall lambda * nu = c, and mind the unit difference; lambda is often Ansgtrom, while c is cm/s)

Note that the conversion is thus wavelength/frequency dependent.

AB mag is given by mag = -2.5 * log10 (f_nu) - 48.60

PFS uses nJy, which is 10^-23 erg/s/cm2/Hz. So, a source with 1 nJy has an AB magnitude of 31.4.

PFS-JIRA