Get the code (version 2010)
IDL download calc_kcor.pro
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; K-corrections calculator in IDL. See http://kcor.sai.msu.ru for the
; reference. Available filter-colour combinations must be present in the
; keys of the 'coeff' structure.
;
; INPUT
; filter_name - name of the bandpass (string).
; At present, SDSS (ugriz), UKIRT WFCAM (YJHK),
; Johnson-Cousins (UBVRcIc), and 2MASS (J2H2Ks2)
; are supported
; redshift - redfshift of a galaxy (floating point)
; colour_name - colour identification (string)
; colour_value - value of colour in magnitudes (floating point)
; should be in the AB mags for ugrizYJHK
; and in Vega mags for Johnson-Cousins/2MASS colours
;
; RETURN VALUE: K-correction in the specified filter for given redshift
; and colour values (floating point)
;
; EXAMPLES OF USAGE:
; IDL> print,calc_kcor('g',0.15,'g - r',1.1)
; 0.481612
; IDL> print,calc_kcor('B',0.2,'B - Rc',1.4)
; 0.618700
;
; AUTHORS: Chilingarian, I., Melchior. A.-L., and Zolotukhin, I. (c) 2010
; LICENSE: Simplified BSD license, see http://kcor.sai.msu.ru/license.txt
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
function calc_kcor, filter_name, redshift, colour_name, colour_value
coeff = {$
B_BRc:[$
[0,0,0,0],$
[-1.99412,3.45377,0.818214,-0.630543],$
[15.9592,-3.99873,6.44175,0.828667],$
[-101.876,-44.4243,-12.6224,0],$
[299.29,86.789,0,0],$
[-304.526,0,0,0]$
],$
H2_H2Ks2:[$
[0,0,0,0],$
[-1.88351,1.19742,10.0062,-18.0133],$
[11.1068,20.6816,-16.6483,139.907],$
[-79.1256,-406.065,-48.6619,-430.432],$
[551.385,1453.82,354.176,473.859],$
[-1728.49,-1785.33,-705.044,0],$
[2027.48,950.465,0,0],$
[-741.198,0,0,0]$
],$
H2_J2H2:[$
[0,0,0,0],$
[-4.99539,5.79815,4.19097,-7.36237],$
[70.4664,-202.698,244.798,-65.7179],$
[-142.831,553.379,-1247.8,574.124],$
[-414.164,1206.23,467.602,-799.626],$
[763.857,-2270.69,1845.38,0],$
[-563.812,-1227.82,0,0],$
[1392.67,0,0,0]$
],$
H_HK:[$
[0,0,0,0],$
[-0.87512,-2.72791,-17.6307,-17.3916],$
[31.4138,111.592,200.198,131.142],$
[-324.271,-788.024,-714.143,-392.762],$
[1352.22,2204.45,1055.26,424.915],$
[-2703.7,-2572,-641.976,0],$
[2491.12,995.135,0,0],$
[-783.755,0,0,0]$
],$
H_JH:[$
[0,0,0,0],$
[-1.78842,3.95359,-4.93259,-8.37687],$
[19.1586,-0.700536,99.4518,-35.4881],$
[-95.0735,-256.834,-188.045,419.65],$
[202.148,943.972,-873.02,-600.689],$
[17.4164,-341.246,1673.54,0],$
[-927.944,-1024.17,0,0],$
[1121.11,0,0,0]$
],$
Ic_VIc:[$
[0,0,0,0],$
[-7.92467,17.6389,-15.2414,5.12562],$
[15.7555,-1.99263,10.663,-10.8329],$
[-88.0145,-42.9575,46.7401,0],$
[266.377,-67.5785,0,0],$
[-164.217,0,0,0]$
],$
J2_J2Ks2:[$
[0,0,0,0],$
[-2.85079,1.7402,0.754404,-0.41967],$
[24.1679,-34.9114,11.6095,0.691538],$
[-32.3501,59.9733,-29.6886,0],$
[-30.2249,43.3261,0,0],$
[-36.8587,0,0,0]$
],$
J2_J2H2:[$
[0,0,0,0],$
[-0.905709,-4.17058,11.5452,-7.7345],$
[5.38206,-6.73039,-5.94359,20.5753],$
[-5.99575,32.9624,-72.08,0],$
[-19.9099,92.1681,0,0],$
[-45.7148,0,0,0]$
],$
J_JK:[$
[0,0,0,0],$
[-0.748177,2.44544,-0.785813,-0.611364],$
[1.10982,-13.8174,16.6888,1.06015],$
[-0.89512,12.109,-35.2342,0],$
[10.3783,34.8843,0,0],$
[-33.2195,0,0,0]$
],$
J_JH:[$
[0,0,0,0],$
[-1.06673,1.73114,-0.672799,-7.63872],$
[3.07102,3.07554,26.2735,18.4105],$
[-10.9191,-41.8091,-66.1621,0],$
[40.8958,88.2172,0,0],$
[-58.7677,0,0,0]$
],$
Ks2_J2Ks2:[$
[0,0,0,0],$
[-5.08065,-0.15919,4.15442,-0.794224],$
[62.8862,-61.9293,-2.11406,1.56637],$
[-191.117,212.626,-15.1137,0],$
[116.797,-151.833,0,0],$
[41.4071,0,0,0]$
],$
Ks2_H2Ks2:[$
[0,0,0,0],$
[-3.90879,5.05938,10.5434,-10.9614],$
[23.6036,-97.0952,14.0686,28.994],$
[-44.4514,266.242,-108.639,0],$
[-15.8337,-117.61,0,0],$
[28.3737,0,0,0]$
],$
K_JK:[$
[0,0,0,0],$
[-2.79151,4.08684,1.8311,-1.16444],$
[12.9577,-41.0232,2.88049,2.64813],$
[-64.5644,114.188,-16.5243,0],$
[132.091,-84.5005,0,0],$
[-95.1022,0,0,0]$
],$
K_HK:[$
[0,0,0,0],$
[-1.31705,5.57641,-4.86809,-9.34749],$
[-2.85707,-42.3794,47.2056,24.9617],$
[-7.17652,100.163,-89.0219,0],$
[56.7029,-66.4791,0,0],$
[-61.2373,0,0,0]$
],$
Rc_BRc:[$
[0,0,0,0],$
[-2.83216,4.64989,-2.86494,0.90422],$
[4.97464,5.34587,0.408024,-2.47204],$
[-57.3361,-30.3302,18.4741,0],$
[224.219,-19.3575,0,0],$
[-194.829,0,0,0]$
],$
U_URc:[$
[0,0,0,0],$
[2.84791,2.31564,-0.411492,-0.0362256],$
[-18.8238,13.2852,6.74212,-2.16222],$
[-307.885,-124.303,-9.92117,12.7453],$
[3040.57,428.811,-124.492,-14.3232],$
[-10677.7,-39.2842,197.445,0],$
[16022.4,-641.309,0,0],$
[-8586.18,0,0,0]$
],$
V_VIc:[$
[0,0,0,0],$
[-1.37734,-1.3982,4.76093,-1.59598],$
[19.0533,-17.9194,8.32856,0.622176],$
[-86.9899,-13.6809,-9.25747,0],$
[305.09,39.4246,0,0],$
[-324.357,0,0,0]$
],$
V_VRc:[$
[0,0,0,0],$
[-2.21628,8.32648,-7.8023,9.53426],$
[13.136,-1.18745,3.66083,-41.3694],$
[-117.152,-28.1502,116.992,0],$
[365.049,-93.68,0,0],$
[-298.582,0,0,0]$
],$
Y_YH:[$
[0,0,0,0],$
[-1.92818,2.26887,6.18075,-4.7355],$
[13.4865,-7.53789,-10.7556,13.6548],$
[-47.959,7.80791,-17.2056,0],$
[86.8046,20.9729,0,0],$
[-67.9877,0,0,0]$
],$
Y_YK:[$
[0,0,0,0],$
[-0.766345,3.06682,0.771616,-2.59031],$
[4.16016,0.0879331,12.9685,6.70949],$
[-45.3704,-62.3077,-35.9553,0],$
[177.731,120.196,0,0],$
[-210.145,0,0,0]$
],$
g_gr:[$
[0,0,0,0],$
[-0.804947,3.32028,1.8793,-1.49],$
[5.32498,-10.753,8.16366,1.89345],$
[-20.3373,-7.42978,-19.021,0],$
[62.8153,47.4034,0,0],$
[-79.5544,0,0,0]$
],$
g_gi:[$
[0,0,0,0],$
[-0.545947,0.299034,3.98684,-1.80155],$
[6.38878,-20.5413,10.0568,2.99832],$
[22.9318,-10.4281,-30.279,0],$
[-21.4324,98.0747,0,0],$
[-86.8239,0,0,0]$
],$
g_gz:[$
[0,0,0,0],$
[0.375663,-1.5098,3.98319,-1.43652],$
[3.50825,-16.9043,7.97596,2.55763],$
[45.0561,-15.9583,-28.1667,0],$
[-64.5893,109.974,0,0],$
[-79.4649,0,0,0]$
],$
i_gi:[$
[0,0,0,0],$
[-2.40717,4.72555,-3.72005,1.47911],$
[10.8559,5.13437,-1.99939,-3.5971],$
[-93.6061,-17.5939,26.5366,0],$
[290.009,-46.9939,0,0],$
[-230.77,0,0,0]$
],$
i_ui:[$
[0,0,0,0],$
[-2.59334,1.58474,-0.212443,0.00262402],$
[18.3125,-4.88146,0.767957,0.0123197],$
[-72.5586,1.37633,-1.33158,0],$
[185.168,11.5798,0,0],$
[-196.516,0,0,0]$
],$
r_gr:[$
[0,0,0,0],$
[-1.61166,3.87173,-3.87312,2.66605],$
[8.48781,13.2126,-6.4946,-7.31552],$
[-87.2971,-35.0474,41.5335,0],$
[271.64,-26.9081,0,0],$
[-232.289,0,0,0]$
],$
r_ur:[$
[0,0,0,0],$
[-1.98173,1.04346,0.0221613,-0.0391318],$
[9.34198,1.639,-0.392805,0.192349],$
[-39.8237,-10.3007,-1.9142,0],$
[123.94,25.7117,0,0],$
[-150.964,0,0,0]$
],$
u_ur:[$
[0,0,0,0],$
[1.54907,2.33077,0.0863027,-0.129934],$
[-67.2858,19.6834,-3.48982,0.769095],$
[227.169,-41.4199,-4.31236,0],$
[-233.872,62.8703,0,0],$
[-18.0493,0,0,0]$
],$
u_ui:[$
[0,0,0,0],$
[1.51973,1.62087,0.314757,-0.118175],$
[-65.2593,17.0211,-3.42331,0.641827],$
[200.74,-20.6839,-5.00841,0],$
[-236.018,52.3746,0,0],$
[-9.91078,0,0,0]$
],$
u_uz:[$
[0,0,0,0],$
[3.23407,0.119541,0.549622,-0.101494],$
[-73.6664,23.7596,-4.88373,0.575285],$
[180.924,-14.7506,-3.00815,0],$
[-217.452,33.4529,0,0],$
[23.5401,0,0,0]$
],$
z_rz:[$
[0,0,0,0],$
[-1.68992,3.2247,0.494208,0.425893],$
[15.0417,-21.8675,-4.54296,1.37908],$
[-44.522,76.0708,-6.46192,0],$
[18.0191,-56.9078,0,0],$
[24.2478,0,0,0]$
],$
z_gz:[$
[0,0,0,0],$
[-3.49804,6.15684,-4.02179,1.26893],$
[12.7541,-1.49658,-2.47768,-2.55071],$
[-60.2735,20.8725,21.5907,0],$
[77.1165,-85.6706,0,0],$
[38.401,0,0,0]$
],$
z_uz:[$
[0,0,0,0],$
[-3.51099,2.17402,-0.332435,0.0209126],$
[24.2976,-9.79764,1.05165,-0.0449372],$
[-52.4363,13.9363,-0.864778,0],$
[52.5216,-3.16925,0,0],$
[-38.931,0,0,0]$
]$
}
tags = tag_names(coeff)
tag_col = strupcase(filter_name+'_'+strcompress(strjoin(strsplit(colour_name,'-',/extr)),/remove_all))
cidx = where(tags eq tag_col, ccnt)
if(ccnt ne 1 or redshift ge 0.5) then begin
message,'Fitting function not found or redshift is out of range',/inf
return,!values.f_nan
endif
c=coeff.(cidx)
s_c = size(c)
kcor=0.0
for i=0, s_c[1]-1 do begin
for j=0, s_c[2]-1 do begin
kcor = kcor+colour_value^i*redshift^j*c[i,j]
endfor
endfor
return, kcor
end
Python download calc_kcor.py
def calc_kcor(filter_name, redshift, colour_name, colour_value): """ K-corrections calculator in Python. See http://kcor.sai.msu.ru for the reference. Available filter-colour combinations must be present in the `coeff` dictionary keys. @type filter_name: string @param filter_name: Name of the filter to calculate K-correction for, e.g. 'u', 'g', 'r' for some of the SDSS filters, or 'J2', 'H2', 'Ks2' for 2MASS filters (must be present in `coeff` dictionary) @type redshift: float @param redshift: Redshift of a galaxy, should be between 0.0 and 0.5 (no check is made, however) @type colour_name: string @param colour_name: Human name of the colour, e.g. 'u - g', 'g - r', 'V - Rc', 'J2 - Ks2' (must be present in `coeff` dictionary) @type colour_value: float @param colour_value: Value of the galaxy's colour, specified in colour_name @rtype: float @return: K-correction in specified filter for given redshift and colour @version: 2010 @author: Chilingarian, I., Melchior. A.-L., and Zolotukhin, I. @license: Simplified BSD license, see http://kcor.sai.msu.ru/license.txt Usage example: >>> calc_kcor('g', 0.2, 'g - r', 1.1) 0.60969373400000026 >>> calc_kcor('Ic', 0.4, 'V - Ic', 2.0) 0.310069919999993 >>> calc_kcor('H', 0.5, 'H - K', 0.1) -0.21574611249999176 """ coeff = { 'B_BRc': [ [0,0,0,0], [-1.99412,3.45377,0.818214,-0.630543], [15.9592,-3.99873,6.44175,0.828667], [-101.876,-44.4243,-12.6224,0], [299.29,86.789,0,0], [-304.526,0,0,0], ], 'H2_H2Ks2': [ [0,0,0,0], [-1.88351,1.19742,10.0062,-18.0133], [11.1068,20.6816,-16.6483,139.907], [-79.1256,-406.065,-48.6619,-430.432], [551.385,1453.82,354.176,473.859], [-1728.49,-1785.33,-705.044,0], [2027.48,950.465,0,0], [-741.198,0,0,0], ], 'H2_J2H2': [ [0,0,0,0], [-4.99539,5.79815,4.19097,-7.36237], [70.4664,-202.698,244.798,-65.7179], [-142.831,553.379,-1247.8,574.124], [-414.164,1206.23,467.602,-799.626], [763.857,-2270.69,1845.38,0], [-563.812,-1227.82,0,0], [1392.67,0,0,0], ], 'H_HK': [ [0,0,0,0], [-0.87512,-2.72791,-17.6307,-17.3916], [31.4138,111.592,200.198,131.142], [-324.271,-788.024,-714.143,-392.762], [1352.22,2204.45,1055.26,424.915], [-2703.7,-2572,-641.976,0], [2491.12,995.135,0,0], [-783.755,0,0,0], ], 'H_JH': [ [0,0,0,0], [-1.78842,3.95359,-4.93259,-8.37687], [19.1586,-0.700536,99.4518,-35.4881], [-95.0735,-256.834,-188.045,419.65], [202.148,943.972,-873.02,-600.689], [17.4164,-341.246,1673.54,0], [-927.944,-1024.17,0,0], [1121.11,0,0,0], ], 'Ic_VIc': [ [0,0,0,0], [-7.92467,17.6389,-15.2414,5.12562], [15.7555,-1.99263,10.663,-10.8329], [-88.0145,-42.9575,46.7401,0], [266.377,-67.5785,0,0], [-164.217,0,0,0], ], 'J2_J2Ks2': [ [0,0,0,0], [-2.85079,1.7402,0.754404,-0.41967], [24.1679,-34.9114,11.6095,0.691538], [-32.3501,59.9733,-29.6886,0], [-30.2249,43.3261,0,0], [-36.8587,0,0,0], ], 'J2_J2H2': [ [0,0,0,0], [-0.905709,-4.17058,11.5452,-7.7345], [5.38206,-6.73039,-5.94359,20.5753], [-5.99575,32.9624,-72.08,0], [-19.9099,92.1681,0,0], [-45.7148,0,0,0], ], 'J_JK': [ [0,0,0,0], [-0.748177,2.44544,-0.785813,-0.611364], [1.10982,-13.8174,16.6888,1.06015], [-0.89512,12.109,-35.2342,0], [10.3783,34.8843,0,0], [-33.2195,0,0,0], ], 'J_JH': [ [0,0,0,0], [-1.06673,1.73114,-0.672799,-7.63872], [3.07102,3.07554,26.2735,18.4105], [-10.9191,-41.8091,-66.1621,0], [40.8958,88.2172,0,0], [-58.7677,0,0,0], ], 'Ks2_J2Ks2': [ [0,0,0,0], [-5.08065,-0.15919,4.15442,-0.794224], [62.8862,-61.9293,-2.11406,1.56637], [-191.117,212.626,-15.1137,0], [116.797,-151.833,0,0], [41.4071,0,0,0], ], 'Ks2_H2Ks2': [ [0,0,0,0], [-3.90879,5.05938,10.5434,-10.9614], [23.6036,-97.0952,14.0686,28.994], [-44.4514,266.242,-108.639,0], [-15.8337,-117.61,0,0], [28.3737,0,0,0], ], 'K_JK': [ [0,0,0,0], [-2.79151,4.08684,1.8311,-1.16444], [12.9577,-41.0232,2.88049,2.64813], [-64.5644,114.188,-16.5243,0], [132.091,-84.5005,0,0], [-95.1022,0,0,0], ], 'K_HK': [ [0,0,0,0], [-1.31705,5.57641,-4.86809,-9.34749], [-2.85707,-42.3794,47.2056,24.9617], [-7.17652,100.163,-89.0219,0], [56.7029,-66.4791,0,0], [-61.2373,0,0,0], ], 'Rc_BRc': [ [0,0,0,0], [-2.83216,4.64989,-2.86494,0.90422], [4.97464,5.34587,0.408024,-2.47204], [-57.3361,-30.3302,18.4741,0], [224.219,-19.3575,0,0], [-194.829,0,0,0], ], 'U_URc': [ [0,0,0,0], [2.84791,2.31564,-0.411492,-0.0362256], [-18.8238,13.2852,6.74212,-2.16222], [-307.885,-124.303,-9.92117,12.7453], [3040.57,428.811,-124.492,-14.3232], [-10677.7,-39.2842,197.445,0], [16022.4,-641.309,0,0], [-8586.18,0,0,0], ], 'V_VIc': [ [0,0,0,0], [-1.37734,-1.3982,4.76093,-1.59598], [19.0533,-17.9194,8.32856,0.622176], [-86.9899,-13.6809,-9.25747,0], [305.09,39.4246,0,0], [-324.357,0,0,0], ], 'V_VRc': [ [0,0,0,0], [-2.21628,8.32648,-7.8023,9.53426], [13.136,-1.18745,3.66083,-41.3694], [-117.152,-28.1502,116.992,0], [365.049,-93.68,0,0], [-298.582,0,0,0], ], 'Y_YH': [ [0,0,0,0], [-1.92818,2.26887,6.18075,-4.7355], [13.4865,-7.53789,-10.7556,13.6548], [-47.959,7.80791,-17.2056,0], [86.8046,20.9729,0,0], [-67.9877,0,0,0], ], 'Y_YK': [ [0,0,0,0], [-0.766345,3.06682,0.771616,-2.59031], [4.16016,0.0879331,12.9685,6.70949], [-45.3704,-62.3077,-35.9553,0], [177.731,120.196,0,0], [-210.145,0,0,0], ], 'g_gr': [ [0,0,0,0], [-0.804947,3.32028,1.8793,-1.49], [5.32498,-10.753,8.16366,1.89345], [-20.3373,-7.42978,-19.021,0], [62.8153,47.4034,0,0], [-79.5544,0,0,0], ], 'g_gi': [ [0,0,0,0], [-0.545947,0.299034,3.98684,-1.80155], [6.38878,-20.5413,10.0568,2.99832], [22.9318,-10.4281,-30.279,0], [-21.4324,98.0747,0,0], [-86.8239,0,0,0], ], 'g_gz': [ [0,0,0,0], [0.375663,-1.5098,3.98319,-1.43652], [3.50825,-16.9043,7.97596,2.55763], [45.0561,-15.9583,-28.1667,0], [-64.5893,109.974,0,0], [-79.4649,0,0,0], ], 'i_gi': [ [0,0,0,0], [-2.40717,4.72555,-3.72005,1.47911], [10.8559,5.13437,-1.99939,-3.5971], [-93.6061,-17.5939,26.5366,0], [290.009,-46.9939,0,0], [-230.77,0,0,0], ], 'i_ui': [ [0,0,0,0], [-2.59334,1.58474,-0.212443,0.00262402], [18.3125,-4.88146,0.767957,0.0123197], [-72.5586,1.37633,-1.33158,0], [185.168,11.5798,0,0], [-196.516,0,0,0], ], 'r_gr': [ [0,0,0,0], [-1.61166,3.87173,-3.87312,2.66605], [8.48781,13.2126,-6.4946,-7.31552], [-87.2971,-35.0474,41.5335,0], [271.64,-26.9081,0,0], [-232.289,0,0,0], ], 'r_ur': [ [0,0,0,0], [-1.98173,1.04346,0.0221613,-0.0391318], [9.34198,1.639,-0.392805,0.192349], [-39.8237,-10.3007,-1.9142,0], [123.94,25.7117,0,0], [-150.964,0,0,0], ], 'u_ur': [ [0,0,0,0], [1.54907,2.33077,0.0863027,-0.129934], [-67.2858,19.6834,-3.48982,0.769095], [227.169,-41.4199,-4.31236,0], [-233.872,62.8703,0,0], [-18.0493,0,0,0], ], 'u_ui': [ [0,0,0,0], [1.51973,1.62087,0.314757,-0.118175], [-65.2593,17.0211,-3.42331,0.641827], [200.74,-20.6839,-5.00841,0], [-236.018,52.3746,0,0], [-9.91078,0,0,0], ], 'u_uz': [ [0,0,0,0], [3.23407,0.119541,0.549622,-0.101494], [-73.6664,23.7596,-4.88373,0.575285], [180.924,-14.7506,-3.00815,0], [-217.452,33.4529,0,0], [23.5401,0,0,0], ], 'z_rz': [ [0,0,0,0], [-1.68992,3.2247,0.494208,0.425893], [15.0417,-21.8675,-4.54296,1.37908], [-44.522,76.0708,-6.46192,0], [18.0191,-56.9078,0,0], [24.2478,0,0,0], ], 'z_gz': [ [0,0,0,0], [-3.49804,6.15684,-4.02179,1.26893], [12.7541,-1.49658,-2.47768,-2.55071], [-60.2735,20.8725,21.5907,0], [77.1165,-85.6706,0,0], [38.401,0,0,0], ], 'z_uz': [ [0,0,0,0], [-3.51099,2.17402,-0.332435,0.0209126], [24.2976,-9.79764,1.05165,-0.0449372], [-52.4363,13.9363,-0.864778,0], [52.5216,-3.16925,0,0], [-38.931,0,0,0], ], } c = coeff[filter_name + '_' + colour_name.replace(' - ', '')] kcor = 0.0 for x, a in enumerate(c): for y, b in enumerate(c[x]): kcor += c[x][y] * redshift**x * colour_value**y return kcor