Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-07-18
Astron.J.134:1843-1848,2007
Astronomy and Astrophysics
Astrophysics
7 pages, 3 figures, uses emulateapj.cls; to appear in the Astronomical Journal; see http://hebe.as.utexas.edu/stools/ to obtai
Scientific paper
10.1086/522051
The measurement of Doppler velocity shifts in spectra is a ubiquitous theme in astronomy, usually handled by computing the cross-correlation of the signals, and finding the location of its maximum. This paper addresses the problem of the determination of wavelength or velocity shifts among multiple spectra of the same, or very similar, objects. We implement the classical cross-correlation method and experiment with several simple models to determine the location of the maximum of the cross-correlation function. We propose a new technique, 'self-improvement', to refine the derived solutions by requiring that the relative velocity for any given pair of spectra is consistent with all others. By exploiting all available information, spectroscopic surveys involving large numbers of similar objects may improve their precision significantly. As an example, we simulate the analysis of a survey of G-type stars with the SDSS instrumentation. Applying 'self-improvement' refines relative radial velocities by more than 50% at low signal-to-noise ratio. The concept is equally applicable to the problem of combining a series of spectroscopic observations of the same object, each with a different Doppler velocity or instrument-related offset, into a single spectrum with an enhanced signal-to-noise ratio.
No associations
LandOfFree
Velocities from Cross-Correlation: A Guide for Self-Improvement 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 Velocities from Cross-Correlation: A Guide for Self-Improvement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Velocities from Cross-Correlation: A Guide for Self-Improvement will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-554244