J/A+A/552/A124 SNLS and SDSS SN surveys photometric calibration (Betoule+, 2013)
Improved photometric calibration of the SNLS and the SDSS supernova surveys.
Betoule M., Marriner J., Regnault N., Cuillandre J.-C., Astier P., Guy J.,
Balland C., El Hage P., Hardin D., Kessler R., Le Guillou L., Mosher J.,
Pain R., Rocci P.-F., Sako M., Schahmaneche K.
<Astron. Astrophys. 552, A124 (2013)>
=2013A&A...552A.124B 2013A&A...552A.124B
ADC_Keywords: Supernovae ; Photometry, sensitivity functions ; Photometry, SDSS
Keywords: cosmology: observations - techniques: photometric -
methods: observational
Description:
We present a joined photometric calibration for the SNLS and the SDSS
supernova surveys.
Our main delivery are catalogs of natural AB magnitudes for a large
set of selected tertiary standard stars covering the science field of
both surveys. Those catalogs are calibrated to the AB flux scale
through observations of 5 primary spectrophotometric standard stars,
for which HST-STIS spectra are available in the CALSPEC database. The
estimate of the uncertainties associated to this calibration are
delivered as a single covariance matrix.
We also provide a model of the transmission efficiency of the SNLS
photometric instrument MegaCam. Those transmission functions are
required for the interpretation of MegaCam natural magnitudes in term
of physical fluxes. Similar curves for the SDSS photometric instrument
have been published in Doi et al. (2010AJ....139.1628D 2010AJ....139.1628D).
Last, we release the measured magnitudes of the five CALSPEC standard
stars in the magnitude system of the tertiary catalogs. This makes it
possible to update the calibration of the tertiary catalogs if CALSPEC
spectra for the primary standards are revised.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablee1.dat 172 601578 SDSS Stripe 82 tertiary star catalog
tablee2.dat 371 17432 SNLS deep-fields tertiary star catalog
tablee3.dat 65 421 MegaCam u transmission curves at several radii
tablee4.dat 65 371 MegaCam g transmission curves at several radii
tablee5.dat 65 371 MegaCam r transmission curves at several radii
tablee6.dat 65 431 MegaCam i transmission curves at several radii
tablee7.dat 65 421 MegaCam i2 transmission curves at several radii
tablee8.dat 65 431 MegaCam z transmission curves at several radii
tablee9.dat 31 84 Measured magnitudes for CALSPEC standards
table22.fit 2880 2 *Covariance matrix of the average calibration
tablee10.fit 2880 2 *Covariance matrix of STIS broadband magnitudes
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Note on table22.fit and tablee10.fit: Covariance matrices are for uM gM rM iM
i2M zM u g r i z magnitudes.
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See also:
J/AJ/135/1766 : Sloan Digital Sky Survey-II supernova survey (Zheng+, 2008)
J/AJ/135/348 : SDSS-II SNe survey: search and follow-up (Sako+, 2008)
J/AJ/136/2306 : SDSS-II Supernova survey, 2005 (Holtzman+, 2008)
J/A+A/506/999 : Photometric Calibration of SNLS (Regnault+, 2009)
Byte-by-byte Description of file: tablee1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg [-51.5,60] Right ascension (J2000)
12- 21 F10.7 deg DEdeg Declination (J2000)
22- 30 F9.7 arcsec rmsRA rms of observed position in RAdeg
31- 39 F9.7 arcsec rmsDE rms of observed position in DEdeg
40- 42 F3.1 mag Ar Reddening in r-band (1)
43- 44 I2 --- o_umag Number of u-band observations
45- 52 F8.4 mag umag ? SDSS u-band natural AB magnitude
53- 58 F6.4 mag e_umag ? Error in u magnitude
59- 64 F6.4 mag s_umag ? Rms of the observations in u
65- 69 F5.1 --- chi2u ? Chi-squared of the u-band observations
70- 71 I2 --- o_gmag Number of g-band observations
72- 78 F7.4 mag gmag SDSS g-band natural AB magnitude
79- 84 F6.4 mag e_gmag Error in g magnitude
85- 90 F6.4 mag s_gmag Rms of the observations in g
91- 93 F3.1 --- chi2g Chi-squared of the g-band observations
94- 95 I2 --- o_rmag Number of r-band observations
96-102 F7.4 mag rmag SDSS r-band natural AB magnitude
103-108 F6.4 mag e_rmag Error in r magnitude
109-114 F6.4 mag s_rmag Rms of the observations in r
115-117 F3.1 --- chi2r Chi-squared of the r-band observations
118-119 I2 --- o_imag Number of i-band observations
120-126 F7.4 mag imag SDSS i-band natural AB magnitude
127-132 F6.4 mag e_imag Error in i magnitude
133-138 F6.4 mag s_imag Rms of the observations in i
139-141 F3.1 --- chi2i Chi-squared of the i-band observations
142-143 I2 --- o_zmag Number of z-band observations
144-151 F8.4 mag zmag ? SDSS z-band natural AB magnitude
152-157 F6.4 mag e_zmag ? Error in z magnitude
158-163 F6.4 mag s_zmag ? Rms of the observations in z
164-166 F3.1 --- chi2z ? Chi-squared of the z-band observations
167-172 I6 --- Index Index in the catalog
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Note (1): Calculated as in SDSS DR7 based on Schlegel, Finkbeiner & Davis
(1998ApJ...500..525S 1998ApJ...500..525S).
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Byte-by-byte Description of file: tablee2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right ascension (J2000)
12- 22 F11.7 deg DEdeg Declination (J2000)
23- 29 F7.4 mag mxu ? CFHT/Megacam u-band natural AB magnitude
30- 36 F7.4 mag mx0u ? CFHT/Megacam u-band uniform AB magnitude (1)
37- 44 F8.4 mag e_mxu ? Error in u magnitude
45- 46 I2 --- o_mxu ? Number of u band measurements
47- 53 F7.1 pix xfp.u ? Average abscissa on the MegaCam FP (2)
54- 60 F7.1 pix yfp.u ? Average ordinate on the MegaCam FP (2)
61- 66 F6.2 --- chi2u ? Reduced chi2 of u-band measurements
67- 70 F4.2 --- airM.u ? Average airmass of u-band observations
71- 74 F4.2 pix IQu ? Average IQ of u-band observations (3)
75- 80 F6.4 mag bgc.u ? Applied background correction in band u
81- 87 F7.4 mag mxg ? CFHT/Megacam g-band natural AB magnitude
88- 94 F7.4 mag mx0g ? CFHT/Megacam g-band uniform AB magnitude (1)
95-100 F6.4 mag e_mxg Error in g magnitude
101-103 I3 --- o_mxg Number of g band measurements
104-110 F7.1 pix xfp.g Average abscissa on the MegaCam FP (2)
111-117 F7.1 pix yfp.g Average ordinate on the MegaCam FP (2)
118-124 F7.2 --- chi2g Reduced chi2 of g-band measurements
125-128 F4.2 --- airM.g ? Average airmass of g-band observations
129-132 F4.2 pix IQg Average IQ of g-band observations (3)
133-138 F6.4 mag bgc.g ? Applied background correction in band g
139-145 F7.4 mag mxr CFHT/Megacam r-band natural AB magnitude
146-152 F7.4 mag mx0r ? CFHT/Megacam r-band uniform AB magnitude (1)
153-158 F6.4 mag e_mxr Error in r magnitude
159-161 I3 --- o_mxr Number of r band measurements
162-168 F7.1 pix xfp.r Average abscissa on the MegaCam FP (2)
169-175 F7.1 pix yfp.r Average ordinate on the MegaCam FP (2)
176-181 F6.2 --- chi2r Reduced chi2 of r-band measurements
182-185 F4.2 --- airM.r Average airmass of r-band observations
186-189 F4.2 pix IQr Average IQ of r-band observations (3)
190-195 F6.4 mag bgc.r Applied background correction in band r
196-202 F7.4 mag mxi ? CFHT/Megacam i-band natural AB magnitude
203-209 F7.4 mag mx0i ? CFHT/Megacam i-band uniform AB magnitude (1)
210-215 F6.4 mag e_mxi Error in i magnitude
216-218 I3 --- o_mxi Number of i band measurements
219-225 F7.1 pix xfp.i Average abscissa on the MegaCam FP (2)
226-232 F7.1 pix yfp.i Average ordinate on the MegaCam FP (2)
233-238 F6.2 --- chi2i Reduced chi2 of i-band measurements
239-242 F4.2 --- airM.i Average airmass of i-band observations
243-246 F4.2 pix IQi Average IQ of i-band observations (3)
247-253 F7.4 mag bgc.i ? Applied background correction in band i
254-260 F7.4 mag mxi2 ? CFHT/Megacam i-band 2nd natural AB magnitude
261-267 F7.4 mag mx0i2 ? CFHT/Megacam i-band uniform AB magnitude (1)
268-273 F6.4 mag e_mxi2 ? Error in i2 magnitude
274-276 I3 --- o_mxi2 ? Number of i2 band measurements
277-283 F7.1 pix xfp.i2 ? Average abscissa on the MegaCam FP (2)
284-290 F7.1 pix yfp.i2 ? Average ordinate on the MegaCam FP (2)
291-299 F9.2 --- chi2i2 ? Reduced chi2 of i2-band measurements
300-303 F4.2 --- airM.i2 ? Average airmass of i2-band observations
304-307 F4.2 pix IQi2 ? Average IQ of i2-band observations (3)
308-314 F7.4 mag bgc.i2 ? Applied background correction in band i2
315-321 F7.4 mag mxz ? CFHT/Megacam z-band natural AB magnitude
322-328 F7.4 mag mx0z ? CFHT/Megacam z-band uniform AB magnitude (1)
329-334 F6.4 mag e_mxz Error in z magnitude
335-337 I3 --- o_mxz Number of z band measurements
338-344 F7.1 pix xfp.z Average abscissa on the MegaCam FP (2)
345-351 F7.1 pix yfp.z Average ordinate on the MegaCam FP (2)
352-357 F6.2 --- chi2z Reduced chi2 of z-band measurements
358-361 F4.2 --- airM.z Average airmass of z-band observations
362-365 F4.2 pix IQz Average IQ of z-band observations (3)
366-371 F6.4 mag bgc.z Applied background correction in band z
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Note (1): Uniform magnitudes are color-transformed from the natural
photometric system at the measurement position to the photometric
system corresponding to the center of the MegaCam focal plane.
Note (2): Origin of coordinates is at one corner of the MegaCam focal
plane. Distance from the center of the focal plane in cm r is given by:
r=0.00135*sqrt((X-9408)2+(Y-9664)2)
Note (3): IQ is defined here as the average σ of a Gaussian fit to
stars on the CCD expressed in pixels (0.187arcsec).
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Byte-by-byte Description of file: tablee[345678].dat
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Bytes Format Units Label Explanations
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1- 5 I5 0.1nm lambda Wavelength
6- 11 F6.4 --- Tr00 Transmission at center
12- 17 F6.4 --- Tr23 Transmission 23mm away from the center
18- 23 F6.4 --- Tr47 Transmission 47mm away from the center
24- 29 F6.4 --- Tr70 Transmission 70mm away from the center
30- 35 F6.4 --- Tr93 Transmission 93mm away from the center
36- 41 F6.4 --- Tr117 Transmission 117mm away from the center
42- 47 F6.4 --- Tr140 Transmission 140mm away from the center
48- 53 F6.4 --- Tr163 Transmission 163mm away from the center
54- 59 F6.4 --- Tr186 Transmission 186mm away from the center
60- 65 F6.4 --- Tr210 Transmission 210mm away from the center
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Byte-by-byte Description of file: tablee9.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Inst Instrument (MegaCam or SDSS2.5)
8- 10 A3 --- Band Photometric band (uM gM rM iM zM i2M u g r i z)
11- 15 A5 --- Star Star name in the CALSPEC database
16- 20 F5.2 cm X ? Abscissa in the MegaCam focalplane (1)
21- 25 F5.2 cm Y ? Ordinate in the MegaCam focalplane (1)
26- 31 F6.3 mag mag Measured magnitude
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Note (1): The origin is taken at the center of the focal-plane, so that the
distance from the center is sqrt(X*X+Y*Y).
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Acknowledgements:
Marc Betoule, betoule(at)lpnhe.in2p3.fr
(End) Marc Betoule [LPNHE], Patricia Vannier [CDS] 20-Dec-2012