How to pass from nice, human readable luminosities to inhuman magnitudes..

[lumtomag1.png]

where
[lumtomag1bis.png]

[lumtomag2.png]

[lumtomag3.png]

where
[lumtomag4.png]

where L is the luminosity per kpc^2 of the galaxy (e.g. from profile of tipsy) and arcsec-per-kpc is the inverse of the 'Scale (Galactocentric GSR)' in NED pages (i.e. the conversion from kpc to arcsec).