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dc.contributor.advisorGeorge R. Ricker.en_US
dc.contributor.authorButler, Nathaniel Richard, 1976-en_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Physics.en_US
dc.date.accessioned2005-05-19T15:39:40Z
dc.date.available2005-05-19T15:39:40Z
dc.date.copyright2003en_US
dc.date.issued2003en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/17015
dc.descriptionThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2003.en_US
dc.descriptionIncludes bibliographical references (p. 121-126).en_US
dc.descriptionThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.en_US
dc.description.abstractThe HETE satellite became operational on the 2nd of February, 2001. In the first 2.5 years of the mission prior to July 1 of 2003, 42 Gamma-ray bursts (GRBs) were promptly localized and publicized over the GRB Coordinates Network (GCN). The first part of this thesis deals with the detection of GRBs in data down-linked from the HETE satellite using a suite of automated routines. This "ground triggering" was designed to supplement the HETE on-board triggering systems. To date, it has facilitated the broadcast of six HETE GRBs to the GCN. A novel trigger search routine using wavelets, which is included in the suite, is discussed. Near real time searches for very long duration (> 300s) GRBs using this and other methods are presented. The second part of the thesis focuses on imaging observations with Chandra of two GRB X-ray afterglows and high-resolution spectroscopic observations of five GRB X-ray afterglows. The imaging observations explore the nature of the class of short/hard GRBs and the class of "optically dark" GRBs, while the spectroscopic observations probe the relation of the long/soft class of GRBs to supernovae. Our observations suggest that no long/soft GRBs are optically dark. Rather, many appear to be "optically faint." In one case, a short/hard GRB may have been optically dark, because it lacked entirely an afterglow in the optical, radio, and X-ray bands. Finally, If the emission lines we detect in a Chandra spectrum of the X-ray afterglow to GRB 020813 are real, then a supernova likely occurred 2 2 months prior to the GRB. The statistical significance of the discrete spectral features reported to date in high resolution spectra taken with Chandra are discussed in detail, as the believability of the features is critical to moving forward in the field.en_US
dc.description.statementofresponsibilityby Nathaniel Richard Butler.en_US
dc.format.extent127 p.en_US
dc.format.extent1710496 bytes
dc.format.extent2721022 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582
dc.subjectPhysics.en_US
dc.titleThe first 2.5 years of the HETE : toward an understanding of the nature of short and long duration gamma-ray burstsen_US
dc.title.alternativeFirst 2.5 years of the High Energy Transient Exploreren_US
dc.typeThesisen_US
dc.description.degreePh.D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Physics.en_US
dc.identifier.oclc54456599en_US


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