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A search for gamma-ray imprints of annihilating dark matter in the galaxy, and the astrophysical implications of ultra-light fundamental vector bosons

Abstract

Standard Model extensions imply new elementary particles that can lead to specific astrophysical signatures. In particular, weakly interacting massive particles (WIMPs) can constitute the unknown non-luminous cold dark matter, which contributes approximately 84% to the matter content of the Universe. Annihilation or decay of WIMPs may lead to high-energy gamma-rays. In this thesis, new methods of searching for gamma-ray signals from annihilating dark matter are developed and applied. Moreover, astrophysical imprints of new ultra-light hidden U(1) gauge bosons in radio data are investigated. Hierarchical structure formation predicts a variety of smaller bound dark matter sub-halos in Milky-Way-like galactic hosts. It is shown that the Fermi-LAT is sufficiently sensitive for detecting up to a few nearby dark matter subhalos in terms of faint gamma-ray sources with a moderate angular extent. Searches in the first and second Fermi-LAT source catalogs reveal about ten candidate sources each. To discriminate the source candidates from conventional astrophysical objects, an analysis for spectral, spatial, positional, and temporal gamma-ray properties using 3.5 years of Fermi-LAT data is carried out. In addition, a multi-wavelength analysis of archival data or follow-up observations in the radio, infrared, optical, UV, X-ray, high-energy, and very-high energy gamma-ray bands is carried out. The  More>>
Publication Date:
Dec 15, 2013
Product Type:
Thesis/Dissertation
Report Number:
DESY-THESIS-2013-041
Resource Relation:
Other Information: Diss.
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANNIHILATION; COSMIC PHOTONS; GAMMA SPECTRA; GRAND UNIFIED THEORY; INFRARED SPECTRA; INTERMEDIATE VECTOR BOSONS; MILKY WAY; NONLUMINOUS MATTER; POSTULATED PARTICLES; U-1 GROUPS; ULTRAVIOLET SPECTRA; VISIBLE SPECTRA; X-RAY SPECTRA
OSTI ID:
22188170
Research Organizations:
Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Dept. Physik
Country of Origin:
Germany
Language:
English
Other Identifying Numbers:
Other: ISSN 1435-8085; TRN: DE14F0010012678
Availability:
Available from INIS in electronic form
Submitting Site:
DE
Size:
221 page(s)
Announcement Date:
Feb 06, 2014

Citation Formats

Zechlin, Hannes-Sebastian. A search for gamma-ray imprints of annihilating dark matter in the galaxy, and the astrophysical implications of ultra-light fundamental vector bosons. Germany: N. p., 2013. Web.
Zechlin, Hannes-Sebastian. A search for gamma-ray imprints of annihilating dark matter in the galaxy, and the astrophysical implications of ultra-light fundamental vector bosons. Germany.
Zechlin, Hannes-Sebastian. 2013. "A search for gamma-ray imprints of annihilating dark matter in the galaxy, and the astrophysical implications of ultra-light fundamental vector bosons." Germany.
@misc{etde_22188170,
title = {A search for gamma-ray imprints of annihilating dark matter in the galaxy, and the astrophysical implications of ultra-light fundamental vector bosons}
author = {Zechlin, Hannes-Sebastian}
abstractNote = {Standard Model extensions imply new elementary particles that can lead to specific astrophysical signatures. In particular, weakly interacting massive particles (WIMPs) can constitute the unknown non-luminous cold dark matter, which contributes approximately 84% to the matter content of the Universe. Annihilation or decay of WIMPs may lead to high-energy gamma-rays. In this thesis, new methods of searching for gamma-ray signals from annihilating dark matter are developed and applied. Moreover, astrophysical imprints of new ultra-light hidden U(1) gauge bosons in radio data are investigated. Hierarchical structure formation predicts a variety of smaller bound dark matter sub-halos in Milky-Way-like galactic hosts. It is shown that the Fermi-LAT is sufficiently sensitive for detecting up to a few nearby dark matter subhalos in terms of faint gamma-ray sources with a moderate angular extent. Searches in the first and second Fermi-LAT source catalogs reveal about ten candidate sources each. To discriminate the source candidates from conventional astrophysical objects, an analysis for spectral, spatial, positional, and temporal gamma-ray properties using 3.5 years of Fermi-LAT data is carried out. In addition, a multi-wavelength analysis of archival data or follow-up observations in the radio, infrared, optical, UV, X-ray, high-energy, and very-high energy gamma-ray bands is carried out. The broad-band spectra of all promising candidates are compatible with AGN, in particular high-energy peaked BL-Lac type objects (HBLs). Dark matter annihilation can contribute to the small-scale angular anisotropy spectrum of the diffuse gamma-ray background (DGB). The detection capabilities of currently operating imaging atmospheric Cherenkov telescopes and the planned Cherenkov Telescope Array (CTA) are studied. With CTA, a relative gamma-ray contribution from annihilating dark matter of 10% to the extragalactic DGB can be resolved via angular anisotropies. In terms of the dark matter velocity-averaged self-annihilation cross section, the sensitivity of CTA corresponds to values below 3 x 10{sup -26} cm{sup 3} s{sup -1} for WIMPs lighter than 200 GeV. Standard Model extensions predict the existence of hidden sector U(1) gauge bosons (hidden photons). It is shown how ultra-light hidden photons with masses below 10{sup -14} eV can modify broad-band spectra of compact radio sources. The sensitivity of current and planned radio astronomical facilities is investigated. Radio observations are capable of probing mixing angles down to 10{sup -3} in a mass range between 10{sup -17} eV and 10{sup -12} eV.}
place = {Germany}
year = {2013}
month = {Dec}
}