Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"Synchrotron emission"”.
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Probing diffuse galactic synchrotron emission using meerkat single dish data
… dominant foreground in our Galaxy which is the synchrotron emission had to be investigated, so they could be removed. This process also provided another validation for the existing data pipeline. As synchrotron emission is modeled using a power law, one way to probe said emission is to measure …
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Radio observations as a tool to study shock interactions and mass ejections in novae
… are utilised to test the hypothesis of radio emission models. First, radio data of V445 Pup are presented. V445 Pup is the only helium nova observed to date; its eruption in late 2000 showed high velocities up to 8500 km s°1, and a remarkable bipolar morphology cinched by an equatorial dust …
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Optical detection and analysis of Pictor A's jet
… particle re-accleration events followed by synchrotron emission could explain the observed knot candidates, but those electrons could not supply enough x-ray ux to match prior observations. Our data provide key evidence suggesting a second, higher energy electron population which was …
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Studies on the gamma-ray burst phenomenon and on its use to probe the high redshift universe
… energy distribution of 22 GRBs shows that synchrotron emission works well for most afterglows as a simple spectral model, on the other hand the dynamical model of the expansion is difficult to reconcile with the observations. A low dust-to-gas ratio is confirmed. The X-ray radiation during …
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High-resolution multi-wavelength study of the jet in 3C273
… 3C273 is one of only a few extragalactic optical synchrotron jets which are large and bright enough to be studied in detail. We present new broad-band observations of this jet at the unprecedented common resolution of 0.3' which have been obtained with the Very Large Array at radio and the Hubble …
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Multi-messenger constraints and pressure from dark matter annihilation into electron-positron pairs
… considering inverse Compton scattering, synchrotron radiation, Coulomb collisions, bremsstrahlung, and ionization. The first part of this work, focusing on pressure from dark matter annihilation, demonstrates that dark matter annihilation into electron-positron pairs may affect the …
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The optical polarization variability of the blazar PKS 2155 304
… and variable objects in the universe. Blazar emission has been detected across the electromagnetic spectrum and exhibits variability on a wide range of timescales, from minutes to years. The observed emission is Doppler boosted and dominated by non-thermal radiation driven by the magnetic …
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An analysis of synchrotron radiation from relativistic electrons in the Alcator C-Mod tokamak
… These so-called "runaway" electrons emit synchrotron radiation in their direction of motion due to their gyration in the background toroidal magnetic field, with values of B0 ranging from 2.7 to 7.8 T at the plasma axis. Two spectrometers, a wide-view camera, and a polarimeter are used to …
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Observational Properties of Gigaelectronvolt-Teraelectronvolt Blazars and the Study of the Teraelectronvolt Blazar RBS 0413 with VERITAS
… Characterization of the non-thermal continuum emission originating from the blazar jet is currently an essential question in high-energy astrophysics. A blazar spectral energy distribution (SED) has a typical double-peaked shape in the flux vs. energy representation. The low-energy component of …
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Radio Observations of Discs around Young Stellar Objects
… = 1.4 ± 0.2, which is indicative of free-free or synchrotron emission. The emission from DG Tau B at cm wavelengths is studied at two epochs. The jet of DG Tau B is resolved with e-MERLIN in both the 2014 and 2016 data, whilst the disc of DG Tau B is only marginally resolved in 2016. The lack of …
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Probing the Gamma-ray Emission from HESS Source RX J1713.7-3946
… and leptonic processes (IC scattering, synchrotron processes and relativistic Bremsstrahlung) involved in the production of the 𝛾-rays are complex and at times intertwined. Hadronic processes are often favoured as the dominant production channel when there is spatially correlated ISM gas …
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Examining the growth and evolution of magnetic fields in clusters of galaxies: a numerical perspective
… to understand and constrain models of diffuse synchrotron emission from clusters. One favored model for generating magnetic fields is through the amplification of weak seed fields in active galactic nuclei (AGN) accretion disks and their subsequent injection into cluster atmospheres via …
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Relativistic Radiative Hydrodynamics Calculation of Accretion Flow into Supermassive Black Hole
… broadband spectrum which likely requires several emission mechanisms for explanation, and structure of innermost accretion flow not yet well constrained, the understanding of accretion into Sgr A* demands advances in both theories and computational calculation. To increase the understanding of Sgr …
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The Bayesian Global Sky Model (B-GSM)
… behaviour and spatial amplitudes of diffuse emission components. Bayesian model comparison, using these Bayesian evidence values, is then used to select the number of emission components and their spectral parametrisation. B-GSM is based on a dataset of nine large area diffuse sky surveys …
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Self-consistent dynamical and radiative models of low-luminosity active galactic nuclei
… transport that treats angle-dependent thermal synchrotron emission and absorption and Compton scattering essentially without approximation. One limitation of \grmonty\ is that it assumes the background emitting plasma (which is provided by, e.g., a simulation) is time-independent which we refer …
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Statistical properties of Radio Halos and the re-acceleration model
… discovered an increasing number of Mpcsized emissions from the ICM, Radio Halos (at the cluster center) and Radio Relics (at the cluster periphery). These sources are due to synchrotron emission from ultra relativistic electrons diffusing through µG turbulent magnetic fields. Radio Halos are …