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Sensitivity Analysis Applied to Atomic Data Used for X-ray Spectrum SynthesisA great deal of work has been devoted to the accumulation of accurate quantities describing atomic processes for use in analysis of astrophysical spectra. But in many situations of interest the interpretation of a quantity which is observed, such as a line flux, depends on the results of a modeling- or spectrum synthesis code. The results of such a code depends in turn 011 many atomic rates or cross sections, and the sensitivity of the observable quantity on the various rates and cross sections may be non-linear and if so cannot easily be derived analytically. In such cases the most practical approach to understanding the sensitivity of observables to atomic cross sections is to perform numerical experiments, by calculating models with various rates perturbed by random (but known) factors. In addition, it is useful to compare the results of such experiments with some sample observations, in order to focus attention on the rates which are of the greatest relevance to real observations. In this paper I will present some attempts to carry out this program, focussing on two sample datasets taken with the Chandra HETG. I will discuss the sensitivity of synthetic spectra to atomic data affecting ionization balance, temperature, and line opacity or emissivity, and discuss the implications for the ultimate goal of inferring astrophysical parameters.
Document ID
20070014874
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Kallman, Tim
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2006
Subject Category
Atomic And Molecular Physics
Meeting Information
Meeting: High Accuracy Atomic Physics in Astronomy
Location: Cambridge, MA
Country: United States
Start Date: August 7, 2006
End Date: August 9, 2006
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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