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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Interstellar gas and hot stars in low density environments

Lehner, Nicolas January 2000 (has links)
No description available.
2

Dark Matter in the Galactic Halo : A Search Using Neutrino Induced Cascades in the DeepCore Extension of IceCube

Taavola, Henric January 2015 (has links)
A search for Weakly Interacting Massive Particles (WIMPs) annihilating in the dark matter halo of the Milky Way was performed, using data from the IceCube Neutrino Observatory and its low-energy extension DeepCore. The data were collected during one year between 2011 to 2012 corresponding to 329.1 days of detector livetime. If WIMPs in the dark matter halo undergo pairwise annihilation they may produce a neutrino signal detectable at the Earth. Assuming annihilation into bb, W+W-, τ+τ-, μ+μ-, νν and a neutrino flavor ratio of 1:1:1 at the detector, cascade events from all neutrino flavors were used to search for an excess of neutrinos matching a dark matter signal spectrum. Two dark matter density profiles for the halo were used; the cored Burkert profile and the cusped NFW profile. No excess of neutrinos from the Galactic halo was observed, and upper limits were set for the thermally averaged product of the WIMP self-annihilation cross section and velocity, <σAv>, in the WIMP mass range 30 GeV to 10 TeV. For the bb annihilation channel and the NFW halo profile, the 90% C.L. upper limits are 9.03×10-22 cm3 s-1 for the mass WIMP 100 GeV and 4.08×10-22 cm3 s-1 for the WIMP mass 3000 GeV. The corresponding upper limits for the μ+μ- annihilation channel are 4.40×10-23 cm3 s-1 and 3.20×10-23 cm3 s-1. / IceCube
3

A New Set of Spectroscopic Metallicity Calibrations for RR Lyrae Variable Stars

Spalding, Eckhart 01 January 2014 (has links)
RR Lyrae stars are old, iron-poor, Helium-burning variable stars. RR Lyraes are extremely useful for tracing phase-space structures and metallicities within the galaxy because they are easy to identify, have consistent luminosities, and are found in large numbers in the galactic disk, bulge, and halo. Here we present a new set of spectroscopic metallicity calibrations that use the equivalent widths of the Ca II K, Hγ, and Hδ lines to calculate metallicity values. Applied to spectroscopic survey data, these calibrations will help shed light on the evolution of the Milky Way and other galaxies.
4

The warm-hot environment of the Milky Way

Williams, Rik Jackson 13 September 2006 (has links)
No description available.
5

Cosmic Ray Instrumentation and Simulations

McBride, Keith William 29 September 2021 (has links)
No description available.
6

RR LYRAE CALIBRATION USING SDSS, SINGLE-EPOCH SPECTROSCOPY

Long, Stacy 01 January 2018 (has links)
I use single-epoch, SDSS spectroscopy of RR Lyraes identified in the Catalina survey to separate the spectra into same-temperature groups. Then I draw temperature-phase diagrams of the groups. I find shocked stars, improperly phased stars, low amplitude stars, and a few that are more likely eclipsing binaries. The RR Lyraes are then given precise metallicities by measurements of the CaII K and H-β, H-γ, and H-δ lines. This leads to better distance measurements, which allow me to confirm a distinction between the inner and outer galactic halo.

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