J/A+A/568/A9 300-2500nm flux calibration reference spectra (Moehler+, 2014)
Flux calibration of medium-resolution spectra from 300 nm to 2500 nm:
Model reference spectra and telluric correction.
Moehler S., Modigliani A., Freudling W., Giammichele N., Gianninas A.,
Gonneau A., Kausch W., Lancon A., Noll S., Rauch T., Vinther J.
<Astron. Astrophys. 568, A9 (2014)>
=2014A&A...568A...9M 2014A&A...568A...9M
ADC_Keywords: Spectrophotometry ; Stars, standard ; Stars, white dwarf
Keywords: standards - techniques: spectroscopic
Abstract:
While the near-infrared wavelength regime is becoming more and more
important for astrophysics there is a marked lack of
spectrophotometric standard star data that allow to flux calibrate
such data. Furthermore flux calibrating medium to high resolution
echelle spectroscopy data is challenging even in the optical
wavelength range, because the available flux standard data are often
too coarsely sampled. We will provide standard star reference data
that allow users to derive response curves from 300nm to 2500nm for
spectroscopic data of medium to high resolution, including those taken
with echelle spectrographs. In addition we describe a method to
correct for moderate telluric absorption without the need of observing
telluric standard stars. As reference data for the flux standard we
use theoretical spectra derived from stellar model atmospheres. We
verify that they provide an appropriate description of the observed
standard star spectra by checking for residuals in line cores and line
overlap regions in the ratios of observed (X-shooter) spectra to model
spectra. The finally selected model spectra are then corrected for
remaining mismatches and photometrically calibrated using independent
observations. The correction of telluric absorption is performed with
the help of telluric model spectra. We provide new, finely sampled
reference spectra without telluric absorption for six southern flux
standard stars that allow the users to flux calibrate their data from
300nm to 2500nm, and a method to correct for telluric absorption
using atmospheric models.
Description:
Reference spectra for six Southern flux standard stars and a DC white
dwarf (L97-3). The reference spectra for the flux standard stars were
derived from model spectra, which were empirically corrected for
deficiencies in the regions of strong line overlap. All reference
spectra were aligned to independently observed photometric data. L97-3
is not a flux standard star, but a DC white dwarf without stellar
features between 300nm and 2500nm, that can be used as a reference
star to identify instrumental features in a response curve.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 47 7 List of stars in this catalog
std.dat 83 145001 Model reference spectra for flux standard stars
dcmod.dat 31 21791 Model reference spectrum for the DC star L97-3
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name
10- 11 I2 h RAh Right Ascension J2000 (hours)
13- 14 I2 min RAm Right Ascension J2000 (minutes)
16- 20 F5.2 s RAs Right Ascension J2000 (seconds)
22 A1 --- DE- Declination J2000 (sign)
23- 24 I2 deg DEd Declination J2000 (degrees)
26- 27 I2 arcmin DEm Declination J2000 (minutes)
29- 32 F4.1 arcsec DEs Declination J2000 (seconds)
34- 38 I5 K Teff [8081/45250] Effective temperature
40- 43 F4.2 [cm/s2] logg [5.8/8.2] Surface gravity
45- 47 A3 --- SpT Spectral type
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Byte-by-byte Description of file: std.dat
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Bytes Format Units Label Explanations
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1- 11 E11.5 nm lambda [300/2500] Wavelength λ
13- 23 E11.5 10mW/m2/nm GD71 Model reference spectrum flux for GD71
25- 35 E11.5 10mW/m2/nm LTT3218 Model reference spectrum flux for LTT3218
37- 47 E11.5 10mW/m2/nm GD153 Model reference spectrum flux for GD153
49- 59 E11.5 10mW/m2/nm EG274 Model reference spectrum flux for EG274
61- 71 E11.5 10mW/m2/nm LTT7987 Model reference spectrum flux for LTT7987
73- 83 E11.5 10mW/m2/nm Feige110 Model reference spectrum flux for Feige110
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Byte-by-byte Description of file: dcmod.dat
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Bytes Format Units Label Explanations
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5- 15 E11.5 nm lambda [320/2500] Wavelength λ
21- 31 E11.5 10mW/m2/nm L97-3 Model reference spectrum flux for L97-3
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Acknowledgements:
Sabine Moehler, smoehler(at)eso.org
(End) Sabine Moehler [ESO, Germany], Patricia Vannier [CDS] 10-Apr-2014