VOSpec Spectral Analysis Tools
A. Laruelo, I. Barbarisi, Jesús J. Salgado, Pedro Osuna · ASPC · 2008
Abstract. We present a series of algorithms for spectral analysis in the con-text of highly distributed data offered by VOSpec,the ESAVO tool for handlingspectra. They have been developed taking into account the requirements pre-sented by the scientist comunity during the Spectroscopy and VO EuroVO-DCAworkshop that took place at ESAC in March 2007(SpectroscopyWorkshop 1 ) 1. IntroductionAnalysis utilities for astronomical data within the VO framework must be readyto deal with a wide variety of data coming from different sources and at differ-ent wavelengths. For spectral analysis tools, that implies dealing with unevenlysamplings and unequal ranges of definition for each spectra. Such tools must alsobe able to deal with grids of theoretical models, variable dimension of the pa-rameters space, multi valuated spectra, interpolation techniques, spectral noiseestimation, etc. The development of utilities capable of handling these issues isa cornerstone of the progress of the analysis of astronomical data.2. Arithmetic and Convolution OperationsVOSpeculator is the tool of VOSpec to perform arithmetic and convolutionoperations among spectra. Arithmetic operations between a spectrum and aconstant can also be performed. In order to not extrapolate and to not decreaseresolution the operations are performed at all wavelength positions of everyinvolved spectra laying within the ranges where such spectra are defined. Seefigure 1.3. Fitting Utilities3.1. Line FittingThe fitting techniques offered by VOSpec are:3.2. PolynomialFits a selected spectral line to a n-grade polynomial using Least Squares fittingmethod.