Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-02-28
Astronomy and Astrophysics
Astrophysics
24 pages, 17 figures, submitted to PASP
Scientific paper
10.1086/376849
We describe a new method to calibrate the relative flux levels in spectra from the HIRES echelle spectrograph on the Keck-I telescope. Standard data reduction techniques that transfer the instrument response between HIRES integrations leave errors in the flux of 5 - 10%, because the effective response varies. The flux errors are most severe near the ends of each spectral order, where there can be discontinuous jumps. The source of these errors is uncertain, but may include changes in the vignetting connected to the optical alignment. Our new flux calibration method uses a calibrated reference spectrum of each target to calibrate individual HIRES integrations. We determine the instrument response independently for each integration, and hence we avoid the need to transfer the instrument response between HIRES integrations. The procedure can be applied to any HIRES spectrum, or any other spectrum. While the accuracy of the method depends upon many factors, we have been able to flux calibrate a HIRES spectrum to 1% over scales of 200 A that include order joins. We illustrate the method with spectra of Q1243+3047 towards which we have measured the deuterium to hydrogen abundance ratio.
Kirkman David
Lubin Dan
O'Meara John M.
Suzuki Nao
Tytler David
No associations
LandOfFree
Relative Flux Calibration of Keck HIRES Echelle Spectra does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Relative Flux Calibration of Keck HIRES Echelle Spectra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Relative Flux Calibration of Keck HIRES Echelle Spectra will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-643424