registration and abstract for the laboratory astrophysics workshop

[Tim Kallman <tim@xstar.gsfc.nasa.gov>]

Last name: Kallman
First name: Tim
Middle name/initial:
Affiliation: NASA/GSFC
Street Address: Code 662
City: Greenbelt
State: MD
Postal Code: 20771
Country: USA
Tel: 301-286-3680
Fax: 301-286-1684
E mail: tim@xstar.gsfc.nasa.gov
Citizenship*: USA
Abstract title: "Sensitivity Analysis Applied to Atomic Data Used for X-ray Spectrum Synthesis"
Special requirements:
*Non-US citizens should contact Cara Loomis if travel reimbursement for the Workshop is required. 





NASA Laboratory Astrophysics Workshop 2006 Abstract Template

Title:

"Sensitivity Analysis Applied to Atomic Data Used for X-ray Spectrum Synthesis"

Author(s):

Author1

T. Kallman
NASA/GSFC

Abstract:

A 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 on 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.