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A Ku-Band Polarimeter for the Owens Valley Radio Observatory 40-Meter Telescope


Karkare, Kirit Sukrit (2011) A Ku-Band Polarimeter for the Owens Valley Radio Observatory 40-Meter Telescope. Senior thesis (Major), California Institute of Technology. doi:10.7907/AX7Y-QF79.


Blazars are active galactic nuclei - small, extremely luminous objects at the center of galaxies powered by material accreting around a supermassive black hole - which emit relativistic jets of highly energetic plasma along our line of sight. There is no accepted model for jet composition, acceleration, and confinement; observations at different wavelengths will help us understand these emission mechanisms. Since 2007, the 40-Meter Telescope at the Owens Valley Radio Observatory has been monitoring over 1100 blazars every two days. The variability in radio light curves is likely to be correlated with gamma-rays, which we are observing with the Fermi Gamma-Ray Space Telescope.

A new Ku-band receiver for the 40-Meter Telescope is in development. It will offer increased sensitivity, MHz spectral resolution from 12-18 GHz, and calculation of Stokes I, Q, and U parameters. In this thesis, I present the design, assembly, and testing of various components in the receiver chain. I evaluate the suitability of a commercial radio frequency over optical link for use in the receiver, describe the fabrication and verification of bandpass filters and sideband separating modules, and present the design and testing of a digital back end spectrometer which uses field-programmable gate array devices.

When complete in late 2011 , the new receiver will allow the continuation of the blazar monitoring program with the addition of spectral and polarization information, which will be invaluable in understanding blazar jet emission.

Item Type:Thesis (Senior thesis (Major))
Subject Keywords:Physics and English (Minor)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Minor Option:English
Thesis Availability:Not set
Research Advisor(s):
  • Readhead, Anthony C. S.
Group:Owens Valley Radio Observatory (OVRO), Astronomy Department
Thesis Committee:
  • None, None
Defense Date:3 May 2011
Record Number:CaltechTHESIS:02132018-113613816
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10708
Deposited By: Joy Painter
Deposited On:14 Feb 2018 00:52
Last Modified:05 Nov 2021 22:37

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