Flux Density Calibration of Radio Bursts Detected in the Sidelobes of the Canadian Hydrogen Intensity Mapping Experiment
Abstract
The Canadian Hydrogen Intensity Mapping Experiment/Fast Radio Burst (CHIME/FRB) instrument is a transient astrophysical burst survey that is discovering FRBs, pulsars, and long-period transients. As a transit telescope, the survey is most sensitive within 2 degrees of the meridian; however, CHIME/FRB can detect bright astrophysical bursts out to its horizon, at 10^-2 to 10^-3 of its peak sensitivity. In this study, we detail the flux density calibration procedure for these bursts detected in the CHIME sidelobes for both channelized voltage (baseband) and intensity data. We validate and estimate the calibration uncertainties by beamforming baseband data towards bright, steady sources in the sidelobes, comparing baseband and intensity flux density calibrations of the same astrophysical transients, and calibrating intensity flux densities for transiting steady sources. We are able to calibrate flux densities for declinations spanning -12 degrees to +59 degrees out to hour angles of 30 degrees, and out to 90 degrees in hour angle for declinations near that of Taurus A (Crab Nebula, declination of about +22 degrees). We conclude that uncertainties in the flux density calibration for transients in the CHIME sidelobes range from 20% to 42%, depending on the data used and the hour angle of the burst.
Related
- The Canadian Galactic Emission Mapper (CGEM): A Cosmic Microwave Foreground Experiment
- Calibration electronics for the 30 and 40 GHz instrument (TFGI) of the QUIJOTE experiment
- Project management of the Canadian Hydrogen Observatory and Radio-transient Detector
- Investigating X-ray emission from radio-detected broad- and narrow-line Seyfert 1 galaxies
- The Canadian Galactic Emission Mapper: A New 8-10 GHz Telescope to Map the Polarization of the Northern Sky
BibTeX
@misc{dong2026flux,
title = {{Flux Density Calibration of Radio Bursts Detected in the Sidelobes of the Canadian Hydrogen Intensity Mapping Experiment}},
author = {Fengqiu Adam Dong and Meena Seth and Paul Scholz and Nina V. Gusinskaia and Kiyoshi W. Masui and Juan Mena-Parra and Daniele Michilli and Ari Polterovich and Ingrid Stairs},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.21074},
eprint = {2609.21074},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.21074},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Flux Density Calibration of Radio Bursts Detected in the Sidelobes of the Canadian Hydrogen Intensity Mapping Experiment
AU - Fengqiu Adam Dong
AU - Meena Seth
AU - Paul Scholz
AU - Nina V. Gusinskaia
AU - Kiyoshi W. Masui
AU - Juan Mena-Parra
AU - Daniele Michilli
AU - Ari Polterovich
AU - Ingrid Stairs
PY - 2026
DA - 2026/09/17
PB - arXiv
DO - 10.48550/arxiv.2609.21074
UR - https://arxiv.org/abs/2609.21074
AB - The Canadian Hydrogen Intensity Mapping Experiment/Fast Radio Burst (CHIME/FRB) instrument is a transient astrophysical burst survey that is discovering FRBs, pulsars, and long-period transients. As a transit telescope, the survey is most sensitive within 2 degrees of the meridian; however, CHIME/FRB can detect bright astrophysical bursts out to its horizon, at 10^-2 to 10^-3 of its peak sensitivity. In this study, we detail the flux density calibration procedure for these bursts detected in the CHIME sidelobes for both channelized voltage (baseband) and intensity data. We validate and estimate the calibration uncertainties by beamforming baseband data towards bright, steady sources in the sidelobes, comparing baseband and intensity flux density calibrations of the same astrophysical transients, and calibrating intensity flux densities for transiting steady sources. We are able to calibrate flux densities for declinations spanning -12 degrees to +59 degrees out to hour angles of 30 degrees, and out to 90 degrees in hour angle for declinations near that of Taurus A (Crab Nebula, declination of about +22 degrees). We conclude that uncertainties in the flux density calibration for transients in the CHIME sidelobes range from 20% to 42%, depending on the data used and the hour angle of the burst.
ER -