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Articles 1 - 5 of 5
Full-Text Articles in Astrophysics and Astronomy
The Search For Heavily Obscured Active Galactic Nuclei In The Local Universe, Ross Silver
The Search For Heavily Obscured Active Galactic Nuclei In The Local Universe, Ross Silver
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Active galactic nuclei (AGN) are supermassive black holes (SMBHs) in the center of galaxies that accrete surrounding gas and emit across the entire electromagnetic spectrum. They are the most energetic persistent emitters in the Universe, capable of outshining their host galaxies despite their emission originating from a region smaller than our Solar System. AGN were some of the first sources discovered that helped teach us that there were galaxies outside of our own, and they proved the existence of black holes. Moreover, AGN can give us valuable insights into other branches of astrophysics. For example, they can be used to …
Exploring The Glow Of The Universe In Gamma-Rays And Hunting Distant Agn, Changam Meenakshi Rajagopal
Exploring The Glow Of The Universe In Gamma-Rays And Hunting Distant Agn, Changam Meenakshi Rajagopal
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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 …
Ion Transport Through Macrocapillaries – Oscillations Due To Charge Patch Formation, Dhruva Kulkarni, L.A.M. Lyle, Chad E. Sosolik
Ion Transport Through Macrocapillaries – Oscillations Due To Charge Patch Formation, Dhruva Kulkarni, L.A.M. Lyle, Chad E. Sosolik
Publications
We present results on ion transport through large bore capillaries (macrocapillaries) that probe both the geometric and ion-guided aspects of this ion delivery mechanism. We have demonstrated that guiding in macrocapillaries exhibits position- and angle-dependent transmission properties which are directly related to the capillary material (either metal or insulator) and geometry. Specifically, we have passed 1 keV Rb+ ions through glass and metal macrocapillaries, and have observed oscillations for the transmitted ion current passing through the insulating capillaries. Straightforward calculations show that these oscillations can be attributed to beam deflections from charge patches that form on the interior walls …
Scalable Synthesis And Energy Applications Of Defect Engineered Nano Materials, Mehmet Karakaya
Scalable Synthesis And Energy Applications Of Defect Engineered Nano Materials, Mehmet Karakaya
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Nanomaterials and nanotechnologies have attracted a great deal of attention in a few decades due to their novel physical properties such as, high aspect ratio, surface morphology, impurities, etc. which lead to unique chemical, optical and electronic properties. The awareness of importance of nanomaterials has motivated researchers to develop nanomaterial growth techniques to further control nanostructures properties such as, size, surface morphology, etc. that may alter their fundamental behavior. Carbon nanotubes (CNTs) are one of the most promising materials with their rigidity, strength, elasticity and electric conductivity for future applications. Despite their excellent properties explored by the abundant research works, …
Multidimensional Simulations Of Non-Linear Cosmic Ray Production In Supernova Remnant Evolution, Joshua Wood
Multidimensional Simulations Of Non-Linear Cosmic Ray Production In Supernova Remnant Evolution, Joshua Wood
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When a high-mass star (& 4Msun) explodes at the end of its life, a supernova occurs, leaving its degenerate core and a fast-moving shell of matter, known as a supernova remnant (SNR). The SNR shell lasts for many thousands of years, generating emissions from low-frequency radio (~ 10-7 eV) up to γ-ray regime (~ 1015 eV). It is also believed that SNRs are the predominant source of galactic cosmic rays, accelerating a population of thermal ions, primarily protons, up to relativistic energies by means of the diffusive shock acceleration (DSA) mechanism. The small population of thermal (Boltzmann) particles, p ~ …