Package uk.ac.starlink.ttools.func
Class Fluxes
- java.lang.Object
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- uk.ac.starlink.ttools.func.Fluxes
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public class Fluxes extends java.lang.Object
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
- Constants
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Field Summary
Fields Modifier and Type Field Description static double
JOHNSON_AB_B
Approximate offset between Johnson and AB magnitudes in B band.static double
JOHNSON_AB_Bj
Approximate offset between Johnson and AB magnitudes in Bj band.static double
JOHNSON_AB_g
Approximate offset between Johnson and AB magnitudes in g band.static double
JOHNSON_AB_gPrime
Offset between Johnson and AB magnitudes in g' band (zero).static double
JOHNSON_AB_i
Approximate offset between Johnson and AB magnitudes in i band.static double
JOHNSON_AB_I
Approximate offset between Johnson and AB magnitudes in I band.static double
JOHNSON_AB_Ic
Approximate offset between Johnson and AB magnitudes in Ic band.static double
JOHNSON_AB_iPrime
Offset between Johnson and AB magnitudes in i' band (zero).static double
JOHNSON_AB_r
Approximate offset between Johnson and AB magnitudes in r band.static double
JOHNSON_AB_R
Approximate offset between Johnson and AB magnitudes in R band.static double
JOHNSON_AB_Rc
Approximate offset between Johnson and AB magnitudes in Rc band.static double
JOHNSON_AB_rPrime
Offset between Johnson and AB magnitudes in r' band (zero).static double
JOHNSON_AB_uPrime
Offset between Johnson and AB magnitudes in u' band (zero).static double
JOHNSON_AB_V
Approximate offset between Johnson and AB magnitudes in V band.static double
JOHNSON_AB_zPrime
Offset between Johnson and AB magnitudes in z' band (zero).static double
VEGA_AB_H
Approximate offset between Vega (as in 2MASS) and AB magnitudes in H band.static double
VEGA_AB_J
Approximate offset between Vega (as in 2MASS) and AB magnitudes in J band.static double
VEGA_AB_K
Approximate offset between Vega (as in 2MASS) and AB magnitudes in K band.
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static 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 Detail
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JOHNSON_AB_V
public static final double JOHNSON_AB_V
Approximate offset between Johnson and AB magnitudes in V band. VJ~=VAB+JOHNSON_AB_V
.- See Also:
- Constant Field Values
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JOHNSON_AB_B
public static final double JOHNSON_AB_B
Approximate offset between Johnson and AB magnitudes in B band. BJ~=BAB+JOHNSON_AB_B
.- See Also:
- Constant Field Values
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JOHNSON_AB_Bj
public static final double JOHNSON_AB_Bj
Approximate offset between Johnson and AB magnitudes in Bj band. BjJ~=BjAB+JOHNSON_AB_Bj
.- See Also:
- Constant Field Values
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JOHNSON_AB_R
public static final double JOHNSON_AB_R
Approximate offset between Johnson and AB magnitudes in R band. RJ~=RAB+JOHNSON_AB_R
.- See Also:
- Constant Field Values
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JOHNSON_AB_I
public static final double JOHNSON_AB_I
Approximate offset between Johnson and AB magnitudes in I band. IJ~=IAB+JOHNSON_AB_I
.- See Also:
- Constant Field Values
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JOHNSON_AB_g
public static final double JOHNSON_AB_g
Approximate offset between Johnson and AB magnitudes in g band. gJ~=gAB+JOHNSON_AB_g
.- See Also:
- Constant Field Values
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JOHNSON_AB_r
public static final double JOHNSON_AB_r
Approximate offset between Johnson and AB magnitudes in r band. rJ~=rAB+JOHNSON_AB_r
.- See Also:
- Constant Field Values
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JOHNSON_AB_i
public static final double JOHNSON_AB_i
Approximate offset between Johnson and AB magnitudes in i band. iJ~=iAB+JOHNSON_AB_i
.- See Also:
- Constant Field Values
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JOHNSON_AB_Rc
public static final double JOHNSON_AB_Rc
Approximate offset between Johnson and AB magnitudes in Rc band. RcJ~=RcAB+JOHNSON_AB_Rc
.- See Also:
- Constant Field Values
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JOHNSON_AB_Ic
public static final double JOHNSON_AB_Ic
Approximate offset between Johnson and AB magnitudes in Ic band. IcJ~=IcAB+JOHNSON_AB_Ic
.- See Also:
- Constant Field Values
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JOHNSON_AB_uPrime
public static final double JOHNSON_AB_uPrime
Offset between Johnson and AB magnitudes in u' band (zero). u'J=u'AB+JOHNSON_AB_uPrime
=u'AB.- See Also:
- Constant Field Values
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JOHNSON_AB_gPrime
public static final double JOHNSON_AB_gPrime
Offset between Johnson and AB magnitudes in g' band (zero). g'J=g'AB+JOHNSON_AB_gPrime
=g'AB.- See Also:
- Constant Field Values
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JOHNSON_AB_rPrime
public static final double JOHNSON_AB_rPrime
Offset between Johnson and AB magnitudes in r' band (zero). r'J=r'AB+JOHNSON_AB_rPrime
=r'AB.- See Also:
- Constant Field Values
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JOHNSON_AB_iPrime
public static final double JOHNSON_AB_iPrime
Offset between Johnson and AB magnitudes in i' band (zero). i'J=i'AB+JOHNSON_AB_iPrime
=i'AB.- See Also:
- Constant Field Values
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JOHNSON_AB_zPrime
public static final double JOHNSON_AB_zPrime
Offset between Johnson and AB magnitudes in z' band (zero). z'J=z'AB+JOHNSON_AB_zPrime
=z'AB.- See Also:
- Constant Field Values
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VEGA_AB_J
public static final double VEGA_AB_J
Approximate offset between Vega (as in 2MASS) and AB magnitudes in J band. JVega~=JAB+VEGA_AB_J
.- See Also:
- Constant Field Values
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VEGA_AB_H
public static final double VEGA_AB_H
Approximate offset between Vega (as in 2MASS) and AB magnitudes in H band. HVega~=HAB+VEGA_AB_H
.- See Also:
- Constant Field Values
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VEGA_AB_K
public static final double VEGA_AB_K
Approximate offset between Vega (as in 2MASS) and AB magnitudes in K band. KVega~=KAB+VEGA_AB_K
.- See Also:
- Constant Field Values
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Method Detail
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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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