Analysis of bremsstrahlung source spectra in terms of integral moments.
Abstract
The problems of deriving temperature structure for thermal hard X-ray sources and electron spectra for nonthermal sources, from their bremsstrahlung continuum spectra, are briefly reviewed and the dangers of model-fitting are reiterated. A more satisfactory approach is developed in terms of the evaluation of integral moments of the distribution function. Using thermal analysis of the impulsive solar hard X-ray burst of 1970 March 1 as an illustration, the integral moment method is shown to give a rapid assessment of the real information content of a bremsstrahlung spectrum. In particular it is shown that due to limitations of bandwidth and, to a lesser extent, of spectral resolution, current hard X-ray spectrometry alone is incapable of distinguishing isothermal, multithermal, and nonthermal sources. Criteria are established for the spectrometer needed to define a thermal source distribution to within some specified accuracy.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1978
- DOI:
- 10.1086/156576
- Bibcode:
- 1978ApJ...225.1076B
- Keywords:
-
- Bremsstrahlung;
- Solar X-Rays;
- Spectrum Analysis;
- Distribution Moments;
- Nonthermal Radiation;
- Solar Spectra;
- Thermal Radiation;
- Solar Physics;
- Bremsstrahlung;
- Solar X Rays: Bursts