The Goodness of Simultaneous Fits in ISIS
Abstract
In a previous work, we introduced a tool for analyzing multiple datasets simultaneously, which has been implemented into ISIS. This tool was used to fit many spectra of X-ray binaries. However, the large number of degrees of freedom and individual datasets raise an issue about a good measure for a simultaneous fit quality. We present three ways to check the goodness of these fits: we investigate the goodness of each fit in all datasets, we define a combined goodness exploiting the logical structure of a simultaneous fit, and we stack the fit residuals of all datasets to detect weak features. These tools are applied to all RXTE-spectra from GRO 1008-57, revealing calibration features that are not detected significantly in any single spectrum. Stacking the residuals from the best-fit model for the Vela X-1 and XTE J1859+083 data evidences fluorescent emission lines that would have gone undetected otherwise.
Keywords
Cite
@article{arxiv.1605.02088,
title = {The Goodness of Simultaneous Fits in ISIS},
author = {Matthias Kühnel and Sebastian Falkner and Christoph Grossberger and Ralf Ballhausen and Thomas Dauser and Fritz-Walter Schwarm and Ingo Kreykenbohm and Michael A. Nowak and Katja Pottschmidt and Carlo Ferrigno and Richard E. Rothschild and Silvia Martínez-Núñez and José Miguel Torrejón and Felix Fürst and Dmitry Klochkov and Rüdiger Staubert and Peter Kretschmar and Jörn Wilms},
journal= {arXiv preprint arXiv:1605.02088},
year = {2016}
}
Comments
6 pages, 6 figures