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Articles 1 - 4 of 4
Full-Text Articles in Physics
An Acoustical Analogue Of A Galactic-Scale Gravitational-Wave Detector, Michael T. Lam, Joseph D. Romano, Joey Key, M. E. Normandin, Jeffrey S. Hazboun
An Acoustical Analogue Of A Galactic-Scale Gravitational-Wave Detector, Michael T. Lam, Joseph D. Romano, Joey Key, M. E. Normandin, Jeffrey S. Hazboun
Physics and Astronomy Faculty Publications and Presentations
By precisely monitoring the “ticks” of Nature's most precise clocks (millisecond pulsars), scientists are trying to detect the “ripples in spacetime” (gravitational waves) produced by the inspirals of supermassive black holes in the centers of distant merging galaxies. Here, we describe a relatively simple demonstration that uses two metronomes and a microphone to illustrate several techniques used by pulsar astronomers to search for and detect gravitational waves. An adapted version of this demonstration could be used as an instructional laboratory investigation at the undergraduate level.
Testing The Production Of Scintillation Arcs With The Pulsar B1133+16, Stella Koch Ocker
Testing The Production Of Scintillation Arcs With The Pulsar B1133+16, Stella Koch Ocker
Honors Papers
Pulsars are extremely dense, highly magnetized stars that emit pulses of radio emission every millisecond or so. The arrival times of their radio signals at Earth observatories can be used as a clock precise enough to detect gravitational waves. Performing such a detection requires the mitigation of interference effects from the interstellar medium: the slightly ionized, mostly hydrogen gas that the radio waves traverse as they travel from the pulsar to Earth. We investigate radio wave delays using a powerful tool: scintillation arcs, fluctuations in frequency and time of the pulsar signal intensity that are manifested as parabolic arcs in …
Simulating Pulsar Signal Scattering In The Interstellar Medium With Two Distinct Scattering Phenomena, Adam P. Jussila
Simulating Pulsar Signal Scattering In The Interstellar Medium With Two Distinct Scattering Phenomena, Adam P. Jussila
Honors Papers
In this thesis, I discuss the creation of a simulation that attempts to reconstruct secondary spectra of pulsars by simulating the scattering in the interstellar medium. For the simulation, we focus on two distinct scattering phenomena, namely a coherent deflection at grazing incidence along a sheet of material, and a random deflection due to a random-walk type process through clouds of material. The simulation focuses on a representation known as a Wavefield Representation that our group has not utilized to this extent before, and it allowed us to understand the physics behind these scattering events in new depths. The final …
First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …