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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:
- Constants
JOHNSON_AB_*
, for Johnson <-> AB magnitude
conversions, from
Frei and Gunn, Astronomical Journal 108, 1476 (1994),
Table 2
(1994AJ....108.1476F).
- Constants
VEGA_AB_*
, for Vega <-> AB magnitude
conversions, from
Blanton et al., Astronomical Journal 129, 2562 (2005),
Eqs. (5)
(2005AJ....129.2562B).
-
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
.
-
abToJansky( magAB )
-
Converts AB magnitude to flux in Jansky.
F/Jy=10(23-(AB+48.6)/2.5)
-
magAB
(floating point): AB magnitude value
- return value (floating point): equivalent flux in Jansky
-
janskyToAb( fluxJansky )
-
Converts flux in Jansky to AB magnitude.
AB=2.5*(23-log10(F/Jy))-48.6
-
fluxJansky
(floating point): flux in Jansky
- return value (floating point): equivalent AB magnitude
-
luminosityToFlux( lumin, dist )
-
Converts luminosity to flux given a luminosity distance.
F=lumin/(4 x Pi x dist2)
-
lumin
(floating point): luminosity
-
dist
(floating point): luminosity distance
- return value (floating point): equivalent flux
-
fluxToLuminosity( flux, dist )
-
Converts flux to luminosity given a luminosity distance.
lumin=(4 x Pi x dist2) F
-
flux
(floating point): flux
-
dist
(floating point): luminosity distance
- return value (floating point): equivalent luminosity
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STILTS - Starlink Tables Infrastructure Library Tool Set
Starlink User Note256
STILTS web page:
http://www.starlink.ac.uk/stilts/
Author email:
m.b.taylor@bristol.ac.uk
Mailing list:
topcat-user@bristol.ac.uk