-
Probing the maximum energy of fast radio bursts using thousands of sources from the Second CHIME/FRB Catalog
Authors:
Vishwangi Shah,
Jason W. T. Hessels,
Victoria M. Kaspi,
Kiyoshi W. Masui,
Mawson W. Sammons,
Daniel Amouyal,
Charanjot Brar,
Shami Chatterjee,
Alice P. Curtin,
Hannah Didehbani,
B. M. Gaensler,
Naman Jain,
Ronniy C. Joseph,
Afrokk Khan,
Bikash Kharel,
Adam E. Lanman,
Kyle McGregor,
Ryan Mckinven,
Mason Ng,
Kenzie Nimmo,
Ayush Pandhi,
Aaron B. Pearlman,
Alexander W. Pollak,
Paul Scholz,
Kaitlyn Shin
, et al. (3 additional authors not shown)
Abstract:
Quantifying the maximum energy of fast radio bursts (FRBs) can provide stringent constraints on their emission mechanisms and progenitor models. However, the most energetic bursts are rare, requiring a large sample of FRBs to detect them. In this work, we use the largest available such sample, 2,998 one-off FRBs from the Second CHIME/FRB Catalog, to obtain a lower limit on the maximum energy (…
▽ More
Quantifying the maximum energy of fast radio bursts (FRBs) can provide stringent constraints on their emission mechanisms and progenitor models. However, the most energetic bursts are rare, requiring a large sample of FRBs to detect them. In this work, we use the largest available such sample, 2,998 one-off FRBs from the Second CHIME/FRB Catalog, to obtain a lower limit on the maximum energy ($E^{\mathrm{max}}_{\mathrm{iso}}$) of FRBs, assuming isotropic energy distribution from FRB sources. In the absence of known redshifts ($z$) for most sources, we present a framework that uses the dispersion measures (DMs) and fluences of these FRBs, together with the probability distribution of $z$ given DM, to derive the lower limit on $E^{\mathrm{max}}_{\mathrm{iso}}$. We generate simulated FRB samples assuming different parameter values for a log-normal $\mathrm{DM}_{\mathrm{host}}$ distribution and a Schechter function form of the FRB energy function to estimate how many outliers -- FRBs with large DM contributions from the host galaxy or intervening galaxy halos -- could artificially inflate this limit. After accounting for outliers, the lower limit on $E^{\mathrm{max}}_{\mathrm{iso}}$ from Catalog 2 FRBs ranges between $1.2\times10^{41}$ and $1.9\times10^{42}$ erg, with best estimate $1.2\times10^{42}$ erg. This limit is consistent with those derived from much smaller FRB samples. Moreover, inferred energies of hundreds of FRBs appear collectively limited around $\sim10^{42}$ erg, suggesting a physical limit on the energy reservoir of FRB sources. The corresponding isotropic-equivalent FRB source energy is consistent with the total energy available in a magnetar's external dipole magnetic field, supporting magnetars as FRB progenitors.
△ Less
Submitted 22 February, 2026;
originally announced February 2026.
-
FRB 20250316A: A Brilliant and Nearby One-Off Fast Radio Burst Localized to 13 parsec Precision
Authors:
The CHIME/FRB Collaboration,
:,
Thomas C. Abbott,
Daniel Amouyal,
Shion E. Andrew,
Kevin Bandura,
Mohit Bhardwaj,
Kalyani Bhopi,
Yash Bhusare,
Charanjot Brar,
Alice Cai,
Tomas Cassanelli,
Shami Chatterjee,
Jean-François Cliche,
Amanda M. Cook,
Alice P. Curtin,
Evan Davies-Velie,
Matt Dobbs,
Fengqiu Adam Dong,
Yuxin Dong,
Gwendolyn Eadie,
Tarraneh Eftekhari,
Wen-fai Fong,
Emmanuel Fonseca,
B. M. Gaensler
, et al. (62 additional authors not shown)
Abstract:
Precise localizations of a small number of repeating fast radio bursts (FRBs) using very long baseline interferometry (VLBI) have enabled multiwavelength follow-up observations revealing diverse local environments. However, the 2--3\% of FRB sources that are observed to repeat may not be representative of the full population. Here we use the VLBI capabilities of the full CHIME Outriggers array for…
▽ More
Precise localizations of a small number of repeating fast radio bursts (FRBs) using very long baseline interferometry (VLBI) have enabled multiwavelength follow-up observations revealing diverse local environments. However, the 2--3\% of FRB sources that are observed to repeat may not be representative of the full population. Here we use the VLBI capabilities of the full CHIME Outriggers array for the first time to localize a nearby (40 Mpc), bright (kJy), and apparently one-off FRB source, FRB 20250316A, to its environment on 13-pc scales. We use optical and radio observations to place deep constraints on associated transient emission and the properties of its local environment. We place a $5σ$ upper limit of $L_{\mathrm{9.9~\mathrm{GHz}}} < 2.1\times10^{25}~\mathrm{erg~s^{-1}~Hz^{-1}}$ on spatially coincident radio emission, a factor of 100 lower than any known compact persistent radio source associated with an FRB. Our KCWI observations allow us to characterize the gas density, metallicity, nature of gas ionization, dust extinction and star-formation rate through emission line fluxes. We leverage the exceptional brightness and proximity of this source to place deep constraints on the repetition of FRB 20250316A, and find it is inconsistent with all well-studied repeaters given the non-detection of bursts at lower spectral energies. We explore the implications of a measured offset of 190$\pm20$ pc from the center of the nearest star-formation region, in the context of progenitor channels. FRB 20250316A marks the beginning of an era of routine localizations for one-off FRBs on tens of mas-scales, enabling large-scale studies of their local environments.
△ Less
Submitted 23 June, 2025;
originally announced June 2025.
-
A Catalog of Local Universe Fast Radio Bursts from CHIME/FRB and the KKO Outrigger
Authors:
The CHIME/FRB Collaboration,
:,
Mandana Amiri,
Daniel Amouyal,
Bridget C. Andersen,
Shion Andrew,
Kevin Bandura,
Mohit Bhardwaj,
P. J. Boyle,
Charanjot Brar,
Alyssa Cassity,
Shami Chatterjee,
Alice P. Curtin,
Matt Dobbs,
Fengqiu Adam Dong,
Yuxin Dong,
Gwendolyn M. Eadie,
Tarraneh Eftekhari,
Wen-fai Fong,
Emmanuel Fonseca,
B. M. Gaensler,
Mark Halpern,
Jason W. T. Hessels,
Hans Hopkins,
Adaeze L. Ibik
, et al. (41 additional authors not shown)
Abstract:
We present the first catalog of fast radio burst (FRB) host galaxies from CHIME/FRB Outriggers, selected uniformly in the radio and the optical by localizing 81 new bursts to 2'' x ~60'' accuracy using CHIME and the KKO Outrigger, located 66 km from CHIME. Of the 81 localized bursts, we use the Probabilistic Association of Transients to their Hosts (PATH) algorithm to securely identify 21 new FRB…
▽ More
We present the first catalog of fast radio burst (FRB) host galaxies from CHIME/FRB Outriggers, selected uniformly in the radio and the optical by localizing 81 new bursts to 2'' x ~60'' accuracy using CHIME and the KKO Outrigger, located 66 km from CHIME. Of the 81 localized bursts, we use the Probabilistic Association of Transients to their Hosts (PATH) algorithm to securely identify 21 new FRB host galaxies, and compile spectroscopic redshifts for 19 systems, 15 of which are newly obtained via spectroscopic observations. The most nearby source is FRB 20231229A, at a distance of 90 Mpc. One burst in our sample is from a previously reported repeating source in a galaxy merger (FRB 20190303A). Three new FRB host galaxies (FRBs 20230203A, 20230703A, and 20231206A) are found towards X-ray and optically selected galaxy clusters, potentially doubling the sample of known galaxy cluster FRBs. A search for radio counterparts reveals that FRB 20231128A is associated with a luminous persistent radio source (PRS) candidate with high significance ($P_{cc} \sim 10^{-2}$). If its compactness is confirmed, it would be the nearest known compact PRS at $z = 0.1079$. Our catalog significantly increases the statistics of the Macquart relation at low redshifts ($z < 0.2$). In the near future, the completed CHIME/FRB Outriggers array will produce hundreds of FRBs localized with very long baseline interferometry (VLBI). This will significantly expand the known sample and pave the way for future telescopes relying on VLBI for FRB localization.
△ Less
Submitted 24 March, 2025; v1 submitted 16 February, 2025;
originally announced February 2025.