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B.1.10 Fluxes

Functions for conversion between flux and magnitude values. Functions are provided for conversion between flux in Janskys and AB magnitudes.

Some constants for approximate conversions between different magnitude scales are also provided:

abToJansky( magAB )
Converts AB magnitude to flux in Jansky.

F/Jy=10(23-(AB+48.6)/2.5)

janskyToAb( fluxJansky )
Converts flux in Jansky to AB magnitude.

AB=2.5*(23-log10(F/Jy))-48.6

luminosityToFlux( lumin, dist )
Converts luminosity to flux given a luminosity distance.

F=lumin/(4 x Pi x dist2)

fluxToLuminosity( flux, dist )
Converts flux to luminosity given a luminosity distance.

lumin=(4 x Pi x dist2) F

JOHNSON_AB_V
Approximate offset between Johnson and AB magnitudes in V band. VJ~=VAB+JOHNSON_AB_V.
JOHNSON_AB_B
Approximate offset between Johnson and AB magnitudes in B band. BJ~=BAB+JOHNSON_AB_B.
JOHNSON_AB_Bj
Approximate offset between Johnson and AB magnitudes in Bj band. BjJ~=BjAB+JOHNSON_AB_Bj.
JOHNSON_AB_R
Approximate offset between Johnson and AB magnitudes in R band. RJ~=RAB+JOHNSON_AB_R.
JOHNSON_AB_I
Approximate offset between Johnson and AB magnitudes in I band. IJ~=IAB+JOHNSON_AB_I.
JOHNSON_AB_g
Approximate offset between Johnson and AB magnitudes in g band. gJ~=gAB+JOHNSON_AB_g.
JOHNSON_AB_r
Approximate offset between Johnson and AB magnitudes in r band. rJ~=rAB+JOHNSON_AB_r.
JOHNSON_AB_i
Approximate offset between Johnson and AB magnitudes in i band. iJ~=iAB+JOHNSON_AB_i.
JOHNSON_AB_Rc
Approximate offset between Johnson and AB magnitudes in Rc band. RcJ~=RcAB+JOHNSON_AB_Rc.
JOHNSON_AB_Ic
Approximate offset between Johnson and AB magnitudes in Ic band. IcJ~=IcAB+JOHNSON_AB_Ic.
JOHNSON_AB_uPrime
Offset between Johnson and AB magnitudes in u' band (zero). u'J=u'AB+JOHNSON_AB_uPrime=u'AB.
JOHNSON_AB_gPrime
Offset between Johnson and AB magnitudes in g' band (zero). g'J=g'AB+JOHNSON_AB_gPrime=g'AB.
JOHNSON_AB_rPrime
Offset between Johnson and AB magnitudes in r' band (zero). r'J=r'AB+JOHNSON_AB_rPrime=r'AB.
JOHNSON_AB_iPrime
Offset between Johnson and AB magnitudes in i' band (zero). i'J=i'AB+JOHNSON_AB_iPrime=i'AB.
JOHNSON_AB_zPrime
Offset between Johnson and AB magnitudes in z' band (zero). z'J=z'AB+JOHNSON_AB_zPrime=z'AB.
VEGA_AB_J
Approximate offset between Vega (as in 2MASS) and AB magnitudes in J band. JVega~=JAB+VEGA_AB_J.
VEGA_AB_H
Approximate offset between Vega (as in 2MASS) and AB magnitudes in H band. HVega~=HAB+VEGA_AB_H.
VEGA_AB_K
Approximate offset between Vega (as in 2MASS) and AB magnitudes in K band. KVega~=KAB+VEGA_AB_K.


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TOPCAT - Tool for OPerations on Catalogues And Tables
Starlink User Note253
TOPCAT web page: http://www.starlink.ac.uk/topcat/
Author email: m.b.taylor@bristol.ac.uk
Mailing list: topcat-user@jiscmail.ac.uk