Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 186-200). Available also in a digital version from Dissertation Abstracts.

Not available / text

published_or_final_version / abstract / toc / Physics / Master / Master of Philosophy

published_or_final_version / Physics / Master / Master of Philosophy

Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves [90]-93).

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

The supernova remnant G109.1-1.0 was observed differentially at 6 cm wavelength using the 91 m transit telescope of the NRAO at Green Bank, West Virginia. After development of a complete declination dependent model of the 6 cm differential response, the observations were restored to the equivalent total intensity observations using the method described by D.T. Emerson et al. (1979) as well as the maximum entropy method of image reconstruction (Gull and Daniell 1978). Both approaches gave successful reconstructions of the field at similar computational costs. The maximum entropy method is shown to provide effective reconstruction even under the sparser sampling conditions of the Gregory-Taylor (1981) survey; allowing the direct application of this work to the majority of the differentially recorded survey data base. The 6 cm observations of G109.1-1.0 indicate an extended half-disc structure which is similar in both shape and extent to the X-ray emission (Gregory and Fahlman 1980) from the remnant. An unusual feature has also become apparent which extends from the northern edge of the remnant for 35 arcmin radially away from the center to the north-west. The generally semicircular shape of the remnant, as indicated by both the X-ray and radio observations, can be understood in terms of an interaction with an adjacent molecular cloud. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 67-71).

We present multiple spectropolarimetric observations of the nearby Type. Ia supernova (SN) 2011fe in M101, obtained before, during, and after the time of maximum apparent visual brightness. The excellent time coverage of our spectropolarimetry has allowed better monitoring of the evolution of polarization features than is typical, which has allowed us new insight into the nature of normal SNe. Ia. SN. 2011fe exhibits time-dependent polarization in both the continuum and strong absorption lines. At early epochs, red wavelengths exhibit a degree of continuum polarization of up to 0.4%, likely indicative of a mild asymmetry in the electron-scattering photosphere. This behavior is more common in subluminous SNe. Ia than in normal events, such as SN. 2011fe. The degree of polarization across a collection of absorption lines varies dramatically from epoch to epoch. During the earliest epoch, lambda 4600-5000 angstrom complex of absorption lines shows enhanced polarization at a different position angle than the continuum. We explore the origin of these features, presenting a few possible interpretations, without arriving at a single favored ion. During two epochs near maximum, the dominant polarization feature is associated with the Si lambda 6355 angstrom absorption line. This is common for SNe. Ia, but for SN. 2011fe the polarization of this feature increases after maximum light, whereas for other SNe. Ia, that polarization feature was strongest before maximum light.

Reproduction de : Thèse de doctorat : Physique et Astrophysique : Lyon 1 : 2006. / Titre provenant de l'écran titre. Bibliogr. p. 191-198.