LOFAR Detection of 110-188MHz emission and frequency-dependent activity from FRB20180916B
Journal article, 2021
The object FRB 20180916B is a well-studied repeating fast radio burst source. Its proximity (∼150 Mpc), along with detailed studies of the bursts, has revealed many clues about its nature, including a 16.3 day periodicity in its activity. Here we report on the detection of 18 bursts using LOFAR at 110-188 MHz, by far the lowest-frequency detections of any FRB to date. Some bursts are seen down to the lowest observed frequency of 110 MHz, suggesting that their spectra extend even lower. These observations provide an order-of-magnitude stronger constraint on the optical depth due to freëCfree absorption in the source's local environment. The absence of circular polarization and nearly flat polarization angle curves are consistent with burst properties seen at 300-1700 MHz. Compared with higher frequencies, the larger burst widths (∼40-160 ms at 150 MHz) and lower linear polarization fractions are likely due to scattering. We find ∼2-3 rad m variations in the Faraday rotation measure that may be correlated with the activity cycle of the source. We compare the LOFAR burst arrival times to those of 38 previously published and 22 newly detected bursts from the uGMRT (200-450 MHz) and CHIME/FRB (400-800 MHz). Simultaneous observations show five CHIME/FRB bursts when no emission is detected by LOFAR. We find that the burst activity is systematically delayed toward lower frequencies by about 3 days from 600 to 150 MHz. We discuss these results in the context of a model in which FRB 20180916B is an interacting binary system featuring a neutron star and high-mass stellar companion.
Author
Z. Pleunis
McGill University
D. Michilli
McGill University
C. G. Bassa
Netherlands Institute for Radio Astronomy (ASTRON)
J. W. T. Hessels
Netherlands Institute for Radio Astronomy (ASTRON)
University of Amsterdam
A. Naidu
University of Oxford
B. Andersen
McGill University
P. Chawla
McGill University
E. Fonseca
West Virginia University
McGill University
A. Gopinath
Netherlands Institute for Radio Astronomy (ASTRON)
University of Amsterdam
V. M. Kaspi
McGill University
V. I. Kondratiev
Netherlands Institute for Radio Astronomy (ASTRON)
Russian Academy of Sciences
D. Z. Li
University of Toronto
Canadian Institute for Theoretical Astrophysics
M. Bhardwaj
McGill University
P. J. Boyle
McGill University
C. Brar
McGill University
T. Cassanelli
University of Toronto
Y. Gupta
National Centre for Radio Astrophysics India
A. Josephy
McGill University
R. Karuppusamy
Max Planck Society
A. Keimpema
Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium (JIVE)
Franz Kirsten
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
C. Leung
Massachusetts Institute of Technology (MIT)
B. Marcote
Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium (JIVE)
K. Masui
Massachusetts Institute of Technology (MIT)
R. Mckinven
University of Toronto
B. W. Meyers
University of British Columbia (UBC)
C. Ng
University of Toronto
K. Nimmo
University of Amsterdam
Netherlands Institute for Radio Astronomy (ASTRON)
Z. Paragi
Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium (JIVE)
M. Rahman
University of Toronto
Sidrat Research
P. Scholz
University of Toronto
K. Shin
Massachusetts Institute of Technology (MIT)
K. M. Smith
Perimeter Institute for Theoretical Physics
I. H. Stairs
University of British Columbia (UBC)
S. P. Tendulkar
National Centre for Radio Astrophysics India
Tata Institute of Fundamental Research
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 911 1 L3Subject Categories
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.3847/2041-8213/abec72