Spectral studies of cosmic X-ray sources

Details Spectral studies of cosmic X-ray sources Spectral studies of cosmic X-ray sources

Jan 1980

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1980phdt.......192b&link_type=abstract

Ph.D. thesis, University of London

Astronomy and Astrophysics

Astronomy

Scientific paper

The conventional "indirect" method of reduction and data analysis of spectral data from non-dispersive X-ray detectors, by the fitting of assumed spectral models, is examined. The limitations of this procedure are presented, and alternative schemes are considered in which the derived spectra are not biased to an astrophysical source model. A new method is developed in detail to directly restore incident photon spectra from the detected count histograms. This Spectral Restoration Technique allows an increase in resolution, to a degree dependent on the statistical precision of the data. This is illustrated by numerical simulations.
Proportional counter data from Ariel 5 are analysed using this technique. The results obtained for the sources Cas A and the Crab Nebula are consistent with previous analyses and show that increases in resolution of up to a factor three are possible in practice.
The source Cyg X-3 is closely examined. Complex spectral variability is found, with the continuum and iron-line emission modulated with the 4.8 hour period of the source. The data suggest multi-component emission in the source. Comparing separate Ariel 5 observations and published data from other experiments, a correlation between the spectral shape and source intensity is evident. The source behaviour is discussed with reference to proposed source models.
Data acquired by the low-energy detectors on-board HEAO-1 are analysed using the Spectral Restoration Technique. This treatment explicitly demonstrates the existence of oxygen K-absorption edges in the soft X-ray spectra of the Crab Nebula and Sco X-1. These results are considered with reference to current theories of the interstellar medium.
The thesis commences with a review of cosmic X-ray sources and the mechanisms responsible for their spectral signatures, and continues with a discussion of the instruments appropriate for spectral studies in X-ray astronomy.

Affiliated with

Also associated with

No associations

Rating

Spectral studies of cosmic X-ray sources does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Spectral studies of cosmic X-ray sources, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectral studies of cosmic X-ray sources will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-882496