Location
King Building 237
Document Type
Presentation
Start Date
4-27-2018 5:30 PM
End Date
4-27-2018 6:50 PM
Abstract
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 the pulsar’s secondary spectrum. While scintillation arcs were first observed by Oberlin students almost two decades ago, the structures that cause them are still unknown. We explore a simple, one-dimensional model for the production of scintillation arcs. A measure of the frequency dependence of scintillation arc widths for the pulsar B1133+16 is suggested for use as an empirical test of scintillation arc models.
Keywords:
astrophysics, pulsars, interstellar medium
Recommended Citation
Ocker, Stella, "Testing the Production of Scintillation Arcs with the Pulsar B1133+16" (04/27/18). Senior Symposium. 77.
https://digitalcommons.oberlin.edu/seniorsymp/2018/presentations/77
Major
Physics
Advisor(s)
Stephen FitzGerald, Physics and Astronomy
Project Mentor(s)
Dan Stinebring, Physics and Astronomy
April 2018
Testing the Production of Scintillation Arcs with the Pulsar B1133+16
King Building 237
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 the pulsar’s secondary spectrum. While scintillation arcs were first observed by Oberlin students almost two decades ago, the structures that cause them are still unknown. We explore a simple, one-dimensional model for the production of scintillation arcs. A measure of the frequency dependence of scintillation arc widths for the pulsar B1133+16 is suggested for use as an empirical test of scintillation arc models.
Notes
Session VII, Panel 19 - Physical | Science
Moderator: Dan Stinebring, Francis D. Federighi Professor of Physics