High-energy Counterparts to Fast Radio Bursts

One of the primary projects of my PhD has been to search for high-energy counterparts to fast radio bursts. More specifically, I am interested in whether fast radio bursts might be radio counterparts to gamma-ray bursts. Gamma-ray bursts (GRBs) are transient gamma-ray events with particularly high energies. GRBs are often split into two categories: short and long GRBs. Short GRBs typically have durations less than 2 seconds, and are thought to be produced during the merger of two compact objects (e.g., a neutron star and a black hole). Long GRBs, on the other hand, typically have durations >2 s and are produced during the collapse of a massive star.

I have led multiple campaigns to search for GRBs associated with FRBs detected by CHIME/FRB. Sadly, we have yet to find any FRBs which might be associated with a GRB. I have also developed an algorithm to use CHIME/FRB to constrain radio emission from transients such as GRBs. Please see my papers on ADS related to this subject for more details.

Image credit: McGill University Graphic Design Team.

Repeating Fast Radio Burst Morphology

I recently started a project using high-time resolution data collected by the CHIME/FRB telescope to study the morphology (time and frequency structure) of all-know repeating FRBs. On this note, I am also part of a smaller team within CHIME/FRB (what we call a tiger team) to develop algorithms to detect microstructure in FRBs. Questions that we hope to answer with this project are:

  • How do the environments of repeaters different from those of non-repeaters?
  • Are there multiple source types for repeaters? Do they live in different environments?
  • Do any repeaters show changing environments?

Initial results from this project were presented at FRB 2023, and can be found here.

Image credit to the CHIME/FRB Collaboration (2020).

CHIME/FRB Outriggers

The CHIME/FRB Outriggers is a transcontinental very long baseline interferometry (VLBI) network of mini-CHIME's located throughout the US and Canada. As a VLBI network, the CHIME/FRB Outriggers will greatly improve the localization capabilities of CHIME such that FRBs can be localized not only to host galaxies, but also to specific points (e.g., spiral arms) within those host galaxies. Currently, two of the three CHIME/FRB Outriggers are operational, with the third under construction.

The CHIME/FRB Outriggers are unique in that unlike traditional-VLBI telescopes, they are not steerable. Additionally, the long baselines (3000 km) and frequency range (400-800 MHz) make using traditional VLBI calibrators difficult. As such, we will use 100 pulsars evenly distributed within CHIME's FOV to calibrate the CHIME/FRB Outriggers. I am leading a massive campaign with the Very Long Baseline Array (VLBA) to obtain positions, proper motions, and parallax for this set of pulsars. The observations for this campaign will finish in February 2024, with results expected Summer 2024.

Data Quality Monitoring for CHIME/FRB

I co-lead the data quality monitoring team for CHIME/FRB. My MsC focused on investigating and characterizing the radio frequency interference (RFI) at CHIME. I developed an algorithm to increase the efficiency of storing RFI metrics by 96% by modeling the RFI in frequency and time using polynomials. I remain one of the team's lead experts on RFI, and the daily data quality.

Image credit: CHIME.

Galactic Magnetic Field

I am also interested in using pulsars to probe the interstellar medium. I am working with Joel Weisberg (Carleton College) and Joanna Ranking (UVM) to map the structure of the magnetic field within the Milky Way using the rotation measures of pulsars. A paper using a newly developed technique along with the application of applying it to a new set of pulsar rotation measures measurements is expected Summer 2024.

Image Credit: NASA/JPL-Caltech.