2 resultados para white dwarfs

em QSpace: Queen's University - Canada


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Halo white dwarfs remain one of the least studied stellar populations in the Milky Way because of their faint luminosities. Recent work has uncovered a population of hot white dwarfs which are thought to be remnants of low-mass Population II stars. This thesis uses optical data from the Next Generation Virgo Cluster Survey (NGVS) and ultravoilet data from the GALEX Ultraviolet Virgo Cluster Survey (GUViCS) to select candidates which may belong to this population of recently formed halo white dwarfs. A colour selection was used to separate white dwarfs from QSOs and main-sequence stars. Photometric distances are calculated using model colour-absolute magnitude relations. Proper motions are calculated by using the difference in positions between objects from the Sloan Digital Sky Survey and the NGVS. The proper motions are combined with the calculated photometric distances to calculate tangential velocities, as well as approximate Galactic space velocities. White dwarf candidates are characterized as belonging to either the disk or the halo using a variety of methods, including calculated scale heights (z> 1 kpc), tangential velocities (vt >200 km/s), and their location in (V,U) space. The 20 halo white dwarf candidates which were selected using Galactic space velocities are analyzed, and their colours and temperatures suggest that these objects represent some of the youngest white dwarfs in the Galactic halo.

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My dissertation examines the traces of inverse (mytho)mysticism, more synchronous with mythical alchemy than transcendent mystery, in H.D.’s mature work (1946-1961). Whereas H.D.’s earliest works respond to a fin de siècle occultism and a collective psyche troubled by the eschatological distress that, as Susan Acheson writes, “was widespread amongst modernist writers grappling with …world events and with the implications of Nietzsche’s inaugural annunciation of modernity in terms of the death of God” (187), her later oeuvre is dedicated to the same work of soul undertaken by the “secret cult of Night” in Vale Ave. Here, her thematic scope faces two ways: backward to ancient Greek mystery cults and their palingenesic rites and forward to depth psychologists searching for the Soul of the World. Vale Ave plays a pronounced role in my study as symbolic guide; in its seventy-four sequences the layering of time in the “trilogy” of past, present, and future that H.D. had explored during the years of the Second World War in order to get behind the fallen walls of cause and effect collapses into two distinct phases of human origin—“meeting” (evolution) and “parting” (involution)—and the poem invites Lilith and Lucifer to be its archetypal guides. My method for the study is imaginal, entering such disciplines as history, philosophy, and theology and bringing psychological understanding to them. John Walsh’s introduction to Vale Ave notes H.D.’s theme “that the human psyche exists in a dimension outside of time and space as well as within them. In Vale Ave, H.D. presents the extremity of this dual-dimensionality: metempsychosis” (vii). However, the concept that H.D. investigates is more than a literary processus of characters who adopt different masks and appear at various junctures in a chronological unwinding of history. I explore H.D.'s works as part of a Modernist tradition of writing “books of the dead” designed not to guide the soul after death, but to draw the gaze upon “a nearer thing,” as H.D. writes in Erige Cor Tuum Ad Me In Caelum, the wisdom intrinsic in the spirit of life itself.