MRI: Development of a CHIME Outrigger Telescope

West Virginia University Research Corporation, Morgantown WV

Investigators

Abstract

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) Outrigger Telescope will be used to pinpoint the location of thousands of bright radio flashes coming from far off galaxies. These Fast Radio Bursts (FRBs) are among the brightest sources ever seen on the sky, but their origin remains a mystery. The new telescope will triangulate source positions by working with the existing CHIME telescope, half a continent away. Currently, most FRB positions are so imprecise that astronomers don’t even know which galaxy they came from. The Outrigger will solve that problem, determining the particular galaxy, and will go further, localizing the source to a specific region within that galaxy. FRBs are interesting because of the extreme physics that creates the flash. In addition, the burst radio waves detected have travelled for billions of years through ionized cosmic structure. Each burst carries several distinct measurable signals imprinted during transit, providing unique new tools to study the cosmos. The CHIME Outrigger program will increase US participation in this exciting new area, and train the next generation of young scientists in this novel type of instrumentation. The Outrigger telescope will allow use of very long baseline interferometry (VLBI) techniques to achieve milli-arcsecond angular resolution in the baseline direction. The telescope we will develop will consist of a single 60 m long by 20 m wide cylinder located at the Green Bank (WV) Observatory. The focal line will be outfitted with 128 dual-polarized quad-clover antennas covering the 400-800 MHz band. Performing untargeted VLBI with this array requires a data recorder capable of storing and processing terabytes of data from all 256 radio-frequency channels, for which we will deploy a memory-based ring buffer with triggered readout. This development program will enable additional outriggers to be built later, allowing even sharper localization of radio bursts, and will pave the way for future construction of larger low-cost, high-throughput telescopes for more advanced transient searches and Intensity Mapping efforts. The program will build expertise in digitally-driven transit telescopes at one of the premier radio observatories in the US. The Outrigger also will serve as a standalone telescope used as an outreach and education platform supporting the broader impacts aspects of this project. This project is jointly funded by MPS/AST, the Established Program to Stimulate Competitive Research (EPSCoR), and the OIA/MRI Program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.