J/AJ/142/153 Precision spectrophotometry at the level of 0.1% (Yan, 2011)
Precision spectrophotometry at the level of 0.1%.
Yan R.
<Astron. J., 142, 153 (2011)>
=2011AJ....142..153Y 2011AJ....142..153Y
ADC_Keywords: Spectrophotometry ; Galaxies, spectra
Keywords: galaxies: evolution - methods: data analysis -
quasars: absorption lines - quasars: emission lines -
techniques: spectroscopic
Abstract:
Accurate relative spectrophotometry is critical for many science
applications. Small wavelength-scale residuals in the flux calibration
can significantly impact the measurements of weak emission and
absorption features in the spectra. Using Sloan Digital Sky Survey
data, we demonstrate that the average spectra of carefully selected
red-sequence galaxies can be used as a spectroscopic standard to
improve the relative spectrophotometry precision to 0.1% on small
wavelength scales (from a few to hundreds of Angstroms). We achieve
this precision by comparing stacked spectra across tiny redshift
intervals. The redshift intervals must be small enough that any
systematic stellar population evolution is minimized and is less than
the spectrophotometric uncertainty. This purely empirical technique
does not require any theoretical knowledge of true galaxy spectra. It
can be applied to all large spectroscopic galaxy redshift surveys that
sample a large number of galaxies in a uniform population.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 17 3890 Residual system response () as a function of
wavelength from stacked spectra of red-sequence
galaxies
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
http://www.mpa-garching.mpg.de/SDSS/ : SDSS studies at MPA/JHU home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 0.1nm lambda Vacuum wavelength λ; in Angstroms
11- 17 F7.5 --- The residual system response value (1)
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Note (1): Since we coadded spectra in three-pixel-wide redshift bins, we are
effectively using a three-pixel-box-smoothed version of R at λ.
See section 2 for further explanations.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 11-Mar-2013