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Full-Text Articles in Astrophysics and Astronomy

Search For High-Energy Gamma Rays From An X-Ray-Selected Blazar Sample, P. T. Reynolds, Et. Al. Dec 2003

Search For High-Energy Gamma Rays From An X-Ray-Selected Blazar Sample, P. T. Reynolds, Et. Al.

Physical Sciences Publications

Our understanding of blazars has been greatly increased in recent years by extensive multiwavelength observations, particularly in the radio, X-ray, and gamma-ray regions. Over the past decade the Whipple 10 m telescope has contributed to this with the detection of five BL Lacertae objects at very high gamma-ray energies. The combination of multiwavelength data has shown that blazars follow a well-defined sequence in terms of their broadband spectral properties. Together with providing constraints on emission models, this information has yielded a means by which potential sources of TeV emission may be identified and predictions made as to their possible gamma-ray …


Search For Tev Emissions From Pulsars In Binary Systems, P. T. Reynolds, Et. Al. Feb 2003

Search For Tev Emissions From Pulsars In Binary Systems, P. T. Reynolds, Et. Al.

Physical Sciences Publications

A survey of binary systems containing pulsars was conducted, with the intention of detecting Galactic sources of very high energy γ-ray emission. Observations were carried out with the Whipple 10 m imaging atmospheric Cerenkov telescope. Standard analysis techniques were applied to these sources to search for steady, unpulsed emission. Periodic tests were also performed to search for emission correlated with both the orbital and spin phases, where appropriate. Analyses indicate that the binaries in this study do not emit detectable levels of very high energy photons within the sensitivity of our instrument. The flux upper limits presented here fail to …


Trace Analysis Of Organic Substances, Alan Giltinan Jan 2003

Trace Analysis Of Organic Substances, Alan Giltinan

Theses

One of the major challenges facing the pharmaceutical industry is the control of the amount of trace contaminants during the manufacture of organic substances. Lowering the level of contamination improves the quality of the product and reduces possible side effects.

One of the main techniques used to detect trace contaminants is UV-VIS spectroscopy, where the unique absorption fingerprint of a chemical reveals its presence. UV-VIS absorption is based upon the Beer-Lambert Law. The critical point to note about this law is that the absorption is exponentially dependent on both the concentration of the absorber and the pathlength traversed by the …