Other Astrophysics and Astronomy Commons^™

Quantifying Noise In Monte Carlo Simulations Of Cosmic Rays In A Shock, Abhro Rahman

Theses and Dissertations

Cosmic rays are a phenomenon known to humankind from the early 1900s, and yet today the details of their physical behavior are not fully settled. While the observed spectral fluxes of cosmic rays follow a power-law trend when plotted against particle energy, the exact mechanisms under which they get to such high energies are still under study. This thesis will undertake a subsection of that task, where the Monte Carlo simulation of particle accelerations is described in Warren (2015), and we aim to identify and quantify the noise inherent in such simulations. This document takes a long path through particle …

Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan

Mathematics, Physics, and Computer Science Faculty Articles and Research

In solar–terrestrial physics, there is an open question: does a geomagnetic storm affect earthquakes? We expand research in this direction, analyzing the seismic situation after geomagnetic storms (GMs) accompanied by the precipitation of relativistic electrons from the outer radiation belt to form an additional radiation belt (RB) around lower geomagnetic lines. We consider four widely discussed cases in the literature for long-lived (weeks, months) RBs due to GMs and revealed that the 1/GMs 24 March 1991 with a new RB at L~2.6 was followed by an M7.0 earthquake in Alaska, 30 May 1991, near footprint L = 2.69; the 2/GMs …

Astrophysics, Cosmology And Particle Phenomenology At The Energy Frontier, Jorge Fernandez Soriano

Dissertations, Theses, and Capstone Projects

This dissertation consists of two parts, treating significantly separated fields. Each part consists on several chapters, each treating a somewhat isolated topic from the rest. In each chapter, I present some of the work developed during my passage through the graduate program, which has mostly been published elsewhere.

Part I – Cosmic Rays and Particle Physics

• Chapter 1: In this chapter we present an introduction to the topic of cosmic ray physics, with an special focus on the so-called ultra high energy cosmic rays: their potential origins, effects during their propagation between their sources and Earth, the different techniques used …

Exploring The Glow Of The Universe In Gamma-Rays And Hunting Distant Agn, Changam Meenakshi Rajagopal

All Dissertations

The entirety of the γ-ray radiation permeating our Universe is encoded in the extragalactic γ-ray background. This is a superposition of resolved sources, mostly powerful relativistic jets powered by supermassive black holes, i.e., blazars, and an unresolved isotropic component, aka, the diffuse isotropic gamma-ray background (IGRB). Studying the IGRB can help unveil its composition, as well as unearth multi-messenger relationships between the intensities of PeV neutrinos, ultra high energy cosmic rays (> 1018 eV), and sub-TeV γ-rays. The comparable energy budgets of these three phenomena (neutrinos, UHECR, and γ-rays) indicates a physical connection or a common source amongst them. On …

Diffuse Gamma-Ray Emission From Nearby Molecular Clouds As A Probe Of Cosmic Ray Density Variations, Ryan Abrahams

Dissertations, Theses, and Capstone Projects

We analyze gamma-ray emission from nearby, interstellar molecular clouds in order to calibrate current tracers of the interstellar medium and to probe local cosmic ray gradients. Gamma-rays detected by the Fermi Gamma-ray Space Telescope are created when cosmic rays collide with atomic nuclei in the interstellar medium, and thus provide a unique, unbiased view of the distribution of gas. The gamma-ray flux per proton in the interstellar medium, also known as the gamma-ray emissivity, contains information about the density of high energy cosmic rays. These cosmic rays are born in supernovae shock waves and diffuse throughout the Galaxy. The cosmic …