J/A+AS/128/409 Wavelength calibration (De Cuyper+ 1998)
Wavelength calibration at moderately high resolution
De Cuyper J.-P., Hensberge H.
<Astron. Astrophys. Suppl. Ser. 128, 409 (1998)>
=1998A&AS..128..409D 1998A&AS..128..409D (SIMBAD/NED BibCode)
ADC_Keywords: Spectroscopy
Keywords: Methods: data analysis - Techniques: spectroscopic
Abstract:
Thorium-Argon lamps are commonly used as wavelength calibration units
at moderately high spectral resolutions because of the richness of the
thorium spectrum in the visual. The inclusion of blended lines whose
position is assumed to coincide with the laboratory wavelength of the
main component is shown to result in a calibration precision
significantly worse than the intrinsic random noise limit. In order to
avoid this degradation of the calibration, we present
resolution-dependent Th-Ar wavelengths in the region 277 to >1000nm
for use at pixel-scales (pixel-size expressed in wavelength units)
between λ/2.5x10+4 and λ/10+5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5a.dat 142 11906 *Principal table for the standard case of the
argon-to-thorium line strength ratio
table5b.dat 142 11906 *Principal table for the argon rich case
table6.dat 36 8540 Selected lines
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Note on table5a.dat: I(ArI 430.01nm)/I(ThI 431.30nm) = 1.267
I(ArII 430.92nm)/I(ThI 430.72nm) = 1.922
Note on table5b.dat: I(ArI 430.01nm)/I(ThI 431.30nm) = 28.68
I(ArII 430.92nm)/I(ThI 430.72nm) = 43.48
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Byte-by-byte Description of file: table5a.dat table5b.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 0.1nm Maincomp Laboratory wavelength of the main component
12- 15 A4 --- Ion Ion emitting the main component
17- 21 F5.2 --- Logint Relative log intensity of the main component
24- 33 F10.4 0.1nm lam025000 ? Blend wavelength for R=25000
35- 44 F10.4 0.1nm lam033333 ? Blend wavelength for R=33333
46- 55 F10.4 0.1nm lam043700 ? Blend wavelength for R=43700
57- 66 F10.4 0.1nm lam050000 ? Blend wavelength for R=50000
68- 77 F10.4 0.1nm lam100000 ? Blend wavelength for R=100000
79- 84 F6.3 pix dp025 ? Displacement of the line for R=25000
86- 90 F5.3 pix s025 ? Discretisation stability of dp025 (1)
92- 97 F6.3 pix dp033 ? Displacement of the line for R=33333
99-103 F5.3 pix s033 ? Discretisation stability of dp033 (1)
105-110 F6.3 pix dp043 ? Displacement of the line for R=43700
112-116 F5.3 pix s043 ? Discretisation stability of dp043 (1)
118-123 F6.3 pix dp050 ? Displacement of the line for R=50000
125-129 F5.3 pix s050 ? Discretisation stability of dp050 (1)
131-136 F6.3 pix dp100 ? Displacement of the line for R=100000
138-142 F5.3 pix s100 ? Discretisation stability of dp100 (1)
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Note (1): The parameter s is the r.m.s. of the blend wavelengths calculated for
20 different discretisations (sub-pixel locations of the line
center) in steps of 0.05pix
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- R Lambda/pixel-scale (1)
9- 18 F10.4 0.1nm Lambda Pixel-scale dependent blend wavelength
21- 30 F10.4 0.1nm Maincomp Laboratory wavelength of the main component
33- 36 A4 --- Ion Ion emitting the main component
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Note (1): Where lambda is the wavelength, and pixel-scale is the pixel-size
expressed in wavelength units
R = 25000; 33333; 43700; 50000; 100000
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Acknowledgements: Jean-Pierre De Cuyper
Both authors carried out the research in the framework of projects initiated
and financed by the Belgian Federal Scientific Services (DWTC/SSTC), under
contract "Service Centres and Research Networks" nr. SC/005 and contract
I.U.A.P. nr. P4/05.
References:
Minnhagen L., 1973, J. Opt. Soc. Am. 63, 1185
Norlen G., 1973, Phys. Scripta 8, 249
Palmer B.A., Engleman R. Jr., 1983, "Atlas of the Thorium Spectrum",
ed. H. Sinoradzky (Los Alamos National Laboratory)
(End) Jean-Pierre De Cuyper[KSB/ORB] 15-May-1997