15,264 research outputs found
Letter from Ray Bowden, Footville, Wisconsin, to Mother, Miffin, Wisconsin, February 22, 1911
No full textThis item is from the Jennie Sheldon Bowden letters. The collection contains letters written to and from Jennie Sheldon Bowden, who lived in Wisconsin. The letters discuss daily life, family, camp meetings, and teaching
Letter from Ray Bowden, Footville, Wisconsin, to Mother, Brodhead, Wisconsin, January 15, 1911
No full textThis item is from the Jennie Sheldon Bowden letters. The collection contains letters written to and from Jennie Sheldon Bowden, who lived in Wisconsin. The letters discuss daily life, family, camp meetings, and teaching
Letter from Ray Bowden, Footville, Wisconsin, to Mother, Brodhead, Wisconsin, November 14, 1911
No full textThis item is from the Jennie Sheldon Bowden letters. The collection contains letters written to and from Jennie Sheldon Bowden, who lived in Wisconsin. The letters discuss daily life, family, camp meetings, and teaching
Letter from Ray Bowden, Whitewater, Wisconsin, to Mother, Brodhead, Wisconsin, May 13, 1913
No full textThis item is from the Jennie Sheldon Bowden letters. The collection contains letters written to and from Jennie Sheldon Bowden, who lived in Wisconsin. The letters discuss daily life, family, camp meetings, and teaching
Letter from Mamma, Brodhead, Wisconsin, to Children, Whitewater, Wisconsin, May 15, 1913
No full textThis item is from the Jennie Sheldon Bowden letters. The collection contains letters written to and from Jennie Sheldon Bowden, who lived in Wisconsin. The letters discuss daily life, family, camp meetings, and teaching
A search for TeV gamma ray emission from X-ray binary stars
No full textThis work is concerned with the detection of pulsed TeV gamma ray emission from a number of X-ray binary systems by the use of the atmospheric Cerenkov technique. Chapters 1 and 2 give an overview of the development of gamma ray astronomy, with emphasis placed on progress made in the detection of TeV gamma rays by their Cerenkov radiation in the atmosphere. Chapters 3 and 4 describe the University of Durham atmospheric Cerenkov telescopes, which were used to make the observations reported in this work, and the standard data processing and analysis procedures adopted. The main part of the thesis deals with the application of these techniques to observations of five X-ray binaries. After a review of the properties of such objects in Chapter 5, Chapters 6 and 7 deal specifically with the results for two of the systems considered to be among the most likely candidates to give a detectable TeV photon flux; Centaurus X-3 and Vela X-1. A study of all data recorded on Cen X-3 over the course of six years suggests the presence of a weak gamma ray flux pulsed at the X-ray period. Previous reports of stronger emission near the ascending node of the orbit are confirmed here. For Vela X-1, the analysis of a dataset recorded during a single dark moon interval reveals evidence for two short outbursts of pulsed TeV gamma ray emission. Chapter 8 reports the series of observations made of SMC X-1, 4U1626-67 and X0G21-72, and upper limits are placed on the TeV gamma ray emission from each. Finally, the results reported here are compared with the predictions of a number of theoretical models, some of which are found to give good agreement with the limits and detections derived in this work. A discussion of the status of this field and future observational prospects is also given
Bowden Family
No full textA Bowden family renuion was held at the Warren Bowden home in Maeser. Pictured from left, back row, Jay Bowden, Mary Bowden Slaugh, June Bowden Fisher, Ethel Bowden, next three unidentified, Wesley Bowden, unidentified, unidentified, Francis Bowden. Center row, Emma Bowden Wilson, DeeAnn Bowden, Louise Wilson, Clara Bowden Arnold, Elaine Fisher, Beb Arnold, Walt Bowden, Dawn Arnold, unidentified, Walter Bowden, Gwen Fisher, last three unidentified. Front, Dale Fisher, Ray Arnold, Dick Bowden, Mike Wilson, Bill Bowden, Paul Wilson, two boys in front unidentified, Bobby Bowden, unidentified little boy, Tom Wilson, Ida Bowden, Carloyn Bowden, Diane Arnold and unidentified girl
[Letter from Alex Bradford to Lieutenant and Mrs. Ray Starner - November 4, 1940]
No full textLetter from Alex Bradford to Lieutenant and Mrs. Ray Starner describing the the current state of affairs that the author was experiencing, including: the London blitz, the moral of the troops on the ground, and the collective company of men opposing the Nazi regime
Gamma ray Cerenkov telescope image analysis
No full textThe subject of this thesis is ground based gamma ray astronomy using the imaging atmospheric Cerenkov technique. The first two chapters are introductory, and describe the field of gamma ray astronomy, the generation of extensive air showers in the atmosphere and the Cerenkov radiation they induce. Chapter three describes the atmospheric Cerenkov telescope, including the development of the imaging technique for background discrimination. The characteristics of the three University of Durham atmospheric Cerenkov telescopes and the processing and calibration of their data products are outlined. Chapter four is concerned with periodic sources of gamma ray emission and includes a review of candidate sources and time series analysis techniques. An analysis of the Mark 3 telescope SMC X-1 database is presented. An upper limit of 1.2 x 10(^-11) cm(^-2) s(^-1) above a cosmic ray threshold of 1 TeV is determined for the guard ring analysis of Mark 3 data. For an analysis of medium resolution Mark 3 imaging data, the upper limit is 2 x 10(^-10) cm(^-2) s(^-1) above a cosmic ray threshold of 500 GeV. Chapter five introduces a new method for the parameterisation of Cerenkov images of extensive air showers recorded by atmospheric Cerenkov telescopes. This method, involving the optimization of a bivariate Gaussian fit to the image, is shown to be significantly better than the standard moment based parameterisation using simulated images. In Chapter six, both of these methods are employed in an attempt to enhance the signal to noise ratio for observations of the pulsar PSR 1706-44 made with the Mark 6 telescope and some evidence for steady emission is seen. The implied fluxes are (2.6 ± 0.3 ± 0.1)x 10(^-11) cm(^-2) s(^-1) above 420 GeV for the bivariate Gaussian analysis and (1.7 ± 0.4 ± 0.2)x10(^-11) cm(^-2) s(^-1) above 500 GeV for the moment analysis
Atmospheric Cerenkov astronomy of cataclysmic variables & other potential gamma ray sources
No full textRecent developments in the application of the atmospheric Cerenkov technique to 7-ray astronomy are reviewed here. These include new methods of signal to noise enhancement and the increasing diversity of stellar systems positively identified as Very High Energy 7-ray sources. Four Cataclysmic Variable systems were observed using the University of Durham Atmospheric Cerenkov telescopes during the course of 1990 and 1991. The statistical analysis performed in the search for a 7-ray signal, above a threshold energy of approximately 0-4 TeV, from three of these objects, H0253+193, EF Eridani and VW Hydri, is described here. The results of this brief survey are discussed in the context of current ideas as to the mechanisms by which Very High Energy 7-rays may be emitted from accreting binary star systems of this type. The analysis techniques applied to Cataclysmic Variable data were extended to an x-ray binary system, Sgr X-7. For comparison, the analysis of data recorded on two radio pulsars, PSR 1855+09 and PSR 1509-58, having more accurately known pulse signatures than the accreting systems is also described here, together with that of the globular cluster 47 Tucanae, which may emit a steady 7-ray flux; an upper limit is placed upon the level of Very High Energy 7-ray emission from this object. Extension of the Very High Energy 7-ray source catalogue will require a further improvement beyond the current signal to noise ratios of atmospheric Cerenkov telescopes. Some features characteristic of the atmospheric Cerenkov emission triggered by Very High Energy 7-rays as opposed to other cosmic ray particles, which could be exploited in an attempt to reduce interference from the latter, are reviewed. The first attempt to obtain directional information from the relative time of arrival of a Cerenkov flash at the telescopes at the University of Durham Southern Hemisphere site, and thus isolate an anisotropic 7-ray flux is reported here
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