J/A+A/585/A113 tellrem package for telluric line removal (Rudolf+, 2016)
Modelling telluric line spectra in the optical and infrared with an application
to VLT/X-Shooter spectra.
Rudolf N., Guenther H.M., Schneider P.C., Schmitt J.H.M.M.
<Astron. Astrophys. 585, A113 (2016)>
=2016A&A...585A.113R 2016A&A...585A.113R (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Spectra, infrared
Keywords: atmospheric effects - instrumentation: spectrographs -
methods: observational - methods: data analysis
Abstract:
Earth's atmosphere imprints a large number of telluric absorption and
emission lines on astronomical spectra, especially in the near
infrared, that need to be removed before analysing the affected
wavelength regions.
These lines are typically removed by comparison to A or B type stars
used as telluric standard that themselves have strong hydrogen lines,
which complicates the removal of telluric lines. We develop a method
to circumvent that problem.
For our IDL software package tellrem we use the approach by Seifahrt
et al. (2010A&A...524A..11S 2010A&A...524A..11S) to model telluric absorption features
with the code LBLRTM (Line-By-Line Radiative Transfer Model). The
broad wavelength coverage of VLT/X-Shooter allows us to expand their
technique by determining the abundances of the most important telluric
molecules H2O, O2, CO2, and CH4 from sufficiently isolated
line groups. For individual observations we construct a telluric
absorption model for most of the spectral range that is used to remove
the telluric absorption from the object spectrum.
We remove telluric absorption from both continuum regions and emission
lines without systematic residuals for most of the processable
spectral range, however, our method increases the statistical errors.
The errors of the corrected spectrum typically increase by 10% for
S/N∼10 and by a factor of two for high quality data (S/N∼100), i.e.,
the method is accurate on the percent level.
Modelling telluric absorption can be an alternative to the observation
of standard stars to remove telluric contamination.
Description:
tellrem v. 1.1, December 2014
routines: directory containing IDL routines
example_files: Files needed for a test run of the software
UserManual.pdf: User Manual describing installation and usage of the
software
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tellrem.tar 114213 53008 Tar file with all tellrem files
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Acknowledgements:
Natascha Rudolf, nrudolf(at)hs.uni-hamburg.de
(End) Natascha Rudolf [Hamburger Sternwarte], Patricia Vannier [CDS] 26-Oct-2015