Package uk.ac.starlink.ttools.func
Class Fluxes
java.lang.Object
uk.ac.starlink.ttools.func.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:
- 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).
- Since:
- 30 Jun 2006
- Author:
- Mark Taylor
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final double
Approximate offset between Johnson and AB magnitudes in B band.static final double
Approximate offset between Johnson and AB magnitudes in Bj band.static final double
Approximate offset between Johnson and AB magnitudes in g band.static final double
Offset between Johnson and AB magnitudes in g' band (zero).static final double
Approximate offset between Johnson and AB magnitudes in i band.static final double
Approximate offset between Johnson and AB magnitudes in I band.static final double
Approximate offset between Johnson and AB magnitudes in Ic band.static final double
Offset between Johnson and AB magnitudes in i' band (zero).static final double
Approximate offset between Johnson and AB magnitudes in r band.static final double
Approximate offset between Johnson and AB magnitudes in R band.static final double
Approximate offset between Johnson and AB magnitudes in Rc band.static final double
Offset between Johnson and AB magnitudes in r' band (zero).static final double
Offset between Johnson and AB magnitudes in u' band (zero).static final double
Approximate offset between Johnson and AB magnitudes in V band.static final double
Offset between Johnson and AB magnitudes in z' band (zero).static final double
Approximate offset between Vega (as in 2MASS) and AB magnitudes in H band.static final double
Approximate offset between Vega (as in 2MASS) and AB magnitudes in J band.static final double
Approximate offset between Vega (as in 2MASS) and AB magnitudes in K band. -
Method Summary
Modifier and TypeMethodDescriptionstatic double
abToJansky
(double magAB) Converts AB magnitude to flux in Jansky.static double
fluxToLuminosity
(double flux, double dist) Converts flux to luminosity given a luminosity distance.static double
janskyToAb
(double fluxJansky) Converts flux in Jansky to AB magnitude.static double
luminosityToFlux
(double lumin, double dist) Converts luminosity to flux given a luminosity distance.
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Field Details
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JOHNSON_AB_V
public static final double JOHNSON_AB_VApproximate offset between Johnson and AB magnitudes in V band. VJ~=VAB+JOHNSON_AB_V
.- See Also:
-
JOHNSON_AB_B
public static final double JOHNSON_AB_BApproximate offset between Johnson and AB magnitudes in B band. BJ~=BAB+JOHNSON_AB_B
.- See Also:
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JOHNSON_AB_Bj
public static final double JOHNSON_AB_BjApproximate offset between Johnson and AB magnitudes in Bj band. BjJ~=BjAB+JOHNSON_AB_Bj
.- See Also:
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JOHNSON_AB_R
public static final double JOHNSON_AB_RApproximate offset between Johnson and AB magnitudes in R band. RJ~=RAB+JOHNSON_AB_R
.- See Also:
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JOHNSON_AB_I
public static final double JOHNSON_AB_IApproximate offset between Johnson and AB magnitudes in I band. IJ~=IAB+JOHNSON_AB_I
.- See Also:
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JOHNSON_AB_g
public static final double JOHNSON_AB_gApproximate offset between Johnson and AB magnitudes in g band. gJ~=gAB+JOHNSON_AB_g
.- See Also:
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JOHNSON_AB_r
public static final double JOHNSON_AB_rApproximate offset between Johnson and AB magnitudes in r band. rJ~=rAB+JOHNSON_AB_r
.- See Also:
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JOHNSON_AB_i
public static final double JOHNSON_AB_iApproximate offset between Johnson and AB magnitudes in i band. iJ~=iAB+JOHNSON_AB_i
.- See Also:
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JOHNSON_AB_Rc
public static final double JOHNSON_AB_RcApproximate offset between Johnson and AB magnitudes in Rc band. RcJ~=RcAB+JOHNSON_AB_Rc
.- See Also:
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JOHNSON_AB_Ic
public static final double JOHNSON_AB_IcApproximate offset between Johnson and AB magnitudes in Ic band. IcJ~=IcAB+JOHNSON_AB_Ic
.- See Also:
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JOHNSON_AB_uPrime
public static final double JOHNSON_AB_uPrimeOffset between Johnson and AB magnitudes in u' band (zero). u'J=u'AB+JOHNSON_AB_uPrime
=u'AB.- See Also:
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JOHNSON_AB_gPrime
public static final double JOHNSON_AB_gPrimeOffset between Johnson and AB magnitudes in g' band (zero). g'J=g'AB+JOHNSON_AB_gPrime
=g'AB.- See Also:
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JOHNSON_AB_rPrime
public static final double JOHNSON_AB_rPrimeOffset between Johnson and AB magnitudes in r' band (zero). r'J=r'AB+JOHNSON_AB_rPrime
=r'AB.- See Also:
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JOHNSON_AB_iPrime
public static final double JOHNSON_AB_iPrimeOffset between Johnson and AB magnitudes in i' band (zero). i'J=i'AB+JOHNSON_AB_iPrime
=i'AB.- See Also:
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JOHNSON_AB_zPrime
public static final double JOHNSON_AB_zPrimeOffset between Johnson and AB magnitudes in z' band (zero). z'J=z'AB+JOHNSON_AB_zPrime
=z'AB.- See Also:
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VEGA_AB_J
public static final double VEGA_AB_JApproximate offset between Vega (as in 2MASS) and AB magnitudes in J band. JVega~=JAB+VEGA_AB_J
.- See Also:
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VEGA_AB_H
public static final double VEGA_AB_HApproximate offset between Vega (as in 2MASS) and AB magnitudes in H band. HVega~=HAB+VEGA_AB_H
.- See Also:
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VEGA_AB_K
public static final double VEGA_AB_KApproximate offset between Vega (as in 2MASS) and AB magnitudes in K band. KVega~=KAB+VEGA_AB_K
.- See Also:
-
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Method Details
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abToJansky
public static double abToJansky(double magAB) Converts AB magnitude to flux in Jansky.F/Jy=10(23-(AB+48.6)/2.5)
- Parameters:
magAB
- AB magnitude value- Returns:
- equivalent flux in Jansky
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janskyToAb
public static double janskyToAb(double fluxJansky) Converts flux in Jansky to AB magnitude.AB=2.5*(23-log10(F/Jy))-48.6
- Parameters:
fluxJansky
- flux in Jansky- Returns:
- equivalent AB magnitude
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luminosityToFlux
public static double luminosityToFlux(double lumin, double dist) Converts luminosity to flux given a luminosity distance.F=lumin/(4 x Pi x dist2)
- Parameters:
lumin
- luminositydist
- luminosity distance- Returns:
- equivalent flux
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fluxToLuminosity
public static double fluxToLuminosity(double flux, double dist) Converts flux to luminosity given a luminosity distance.lumin=(4 x Pi x dist2) F
- Parameters:
flux
- fluxdist
- luminosity distance- Returns:
- equivalent luminosity
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