Explanipedia

Investigating the Sightline of a Highly Scattered Fast Radio Burst through a Cosmic Sheet Structure in the Local Universe Open

Kaitlyn Shin, Calvin Leung, Sunil Simha, Bridget C. Andersen, Emmanuel Fonseca , et al. · 2025

Fast radio bursts (FRBs) are unique probes of extragalactic ionized baryonic structure as each signal, through its burst properties, holds information about the ionized matter it encounters along its sightline. FRB 20200723B is a burst wit…

CHIME/FRB Outriggers: Design Overview Open

M. Amiri, Bridget C. Andersen, Shion Andrew, Kevin Bandura, Mohit Bhardwaj , et al. · 2025

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) has emerged as the world’s premier facility for studying fast radio bursts (FRBs) through its fast transient search backend CHIME/FRB. The CHIME/FRB Outriggers project will augment…

CHIME-o-Grav: Wideband Timing of Four Millisecond Pulsars from the NANOGrav 15-yr dataset Open

Gabriella Agazie, D. L. Kaplan, Abhimanyu Susobhanan, I. H. Stairs, Deborah C. Good , et al. · 2025

Wideband timing of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) datasets, where a single time-of-arrival (TOA) and a single dispersion measure (DM) are measured using the entire bandwidth of each observation,…

Searching for Exotrojans in Pulsar Binary Systems Open

Jacob Taylor, Emmanuel Fonseca, Lankeswar Dey, S. V. Zharikov, A. Yu. Kirichenko , et al. · 2025

Trojan asteroids are found in the equilateral triangle Lagrange points of the Sun-Jupiter system in great number, though they also exist less prolifically in other Sun-planet systems. Despite up to planetary mass Trojans being predicted in…

Morphology of 35 Repeating Fast Radio Burst Sources at Microsecond Time Scales with CHIME/FRB Open

Alice P. Curtin, Ketan R. Sand, Ziggy Pleunis, Naman Jain, V. M. Kaspi , et al. · 2025

The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) project has discovered the most repeating FRB sources of any telescope. However, most of the physical conclusions derived from this sample are based on data wi…

Testing Gravitation from Light-second to Cosmological Scales with Radio Pulsars Open

Emmanuel Fonseca · 2025

Pulsars are spinning neutron stars typically observed as pulses emitted at radio wavelengths. These pulsations exhibit a rotational stability that rival the best atomic clocks, making pulsars one of the most important tools for resolving g…

Searching for Historical Extragalactic Optical Transients Associated with Fast Radio Bursts Open

Yuxin 雨欣 Dong 董, C. D. Kilpatrick, Wen‐fai Fong, Alice P. Curtin, S. Opoku , et al. · 2025

We present a systematic search for past supernovae (SNe) and other historical optical transients at the positions of fast radio burst (FRB) sources to test FRB progenitor systems. Our sample comprises 83 FRBs detected by the Canadian Hydro…

The NANOGrav 15-Year Data Set: Improved Timing Precision With VLBI Astrometric Priors Open

Sophia V. Sosa Fiscella, Michael T. Lam, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald , et al. · 2025

Accurate pulsar astrometric estimates play an essential role in almost all high-precision pulsar timing experiments. Traditional pulsar timing techniques refine these estimates by including them as free parameters when fitting a model to o…

A Spatial Gap in the Sky Distribution of Fast Radio Burst Detections Coinciding with Galactic Plasma Overdensities Open

Swarali Shivraj Patil, Robert Main, Emmanuel Fonseca, Kyle McGregor, B. M. Gaensler , et al. · 2025

We analyze the positional and morphological properties of about 3600 unique fast radio burst (FRB) sources reported in the second FRB catalog generated by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. We find a two-…

Repeating vs. Non-Repeating FRBs: A Deep Learning Approach To Morphological Characterization Open

Bikash Kharel, Emmanuel Fonseca, Charanjot Brar, A. M. Khan, Lluís Mas-Ribas , et al. · 2025

We present a deep learning approach to classify fast radio bursts (FRBs) based purely on morphology as encoded on recorded dynamic spectrum from CHIME/FRB Catalog 2. We implemented transfer learning with a pretrained ConvNext architecture,…

CHIME/Fast Radio Burst/Pulsar Discovery of a Nearby Long-period Radio Transient with a Timing Glitch Open

Fengqiu Adam Dong, T. E. Clarke, Alice P. Curtin, Ajay Kumar, Ryan Mckinven , et al. · 2025

We present the discovery of a 421 s long period transient using the CHIME telescope, CHIME J0630+25. The source is localized to R.A. = 06:30:38.4 decl. = 25:26:23 using voltage data acquired with the CHIME baseband system. A timing…

CHIME All-sky Multiday Pulsar Stacking Search (CHAMPSS): System Overview and First Discoveries Open

Christopher Andrade, P. J. Boyle, Charanjot Brar, Alyssa Cassity, Kathryn Crowter , et al. · 2025

We describe the Canadian Hydrogen Intensity Mapping Experiment (CHIME) All-sky Multiday Pulsar Stacking Search (CHAMPSS) project. This novel radio pulsar survey revisits the full northern sky daily, offering unprecedented opportunity to de…

FRB 20250316A: A Brilliant and Nearby One-off Fast Radio Burst Localized to 13 pc Precision Open

Thomas C. Abbott, Daniel Amouyal, Bridget C. Andersen, Shion Andrew, Kevin Bandura , et al. · 2025

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 FR…

A Catalog of Local Universe Fast Radio Bursts from CHIME/FRB and the KKO Open

M. Amiri, Daniel Amouyal, Bridget C. Andersen, Shion Andrew, Kevin Bandura , et al. · 2025

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″ × ∼ 60″ accuracy using CHIME and the k’niʔatn k’l ⌣ stk’masqt…

CHIME/Fast Radio Burst Discovery of an Unusual Circularly Polarized Long-period Radio Transient with an Accelerating Spin Period Open

Fengqiu Adam Dong, Kaitlyn Shin, Casey Law, Mason Ng, I. H. Stairs , et al. · 2025

We report the discovery of CHIME J1634+44, a long-period radio transient (LPT) unique for two aspects: it is the first known LPT to emit fully circularly polarized radio bursts, and it is the first LPT with a significant spin-up. Given tha…

FRB 20250316A: A Brilliant and Nearby One-Off Fast Radio Burst Localized to 13 parsec Precision Open

FRB Collaboration, Thomas C. Abbott, Daniel Amouyal, Shion Andrew, Kevin Bandura , et al. · 2025

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 F…

The NANOGrav 15 yr Data Set: Search for Gravitational-wave Memory Open

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, J. G. Baier , et al. · 2025

We present the results of a search for nonlinear gravitational-wave (GW) memory in the NANOGrav 15 yr data set. We find no significant evidence for memory signals in the data set, with a maximum Bayes factor of 3.1 in favor of a model incl…

The NANOGrav 12.5 yr Data Set: Probing Interstellar Turbulence and Precision Pulsar Timing with PSR J1903+0327 Open

Abra Geiger, J. M. Cordes, Michael T. Lam, Stella Koch Ocker, Shami Chatterjee , et al. · 2025

Free electrons in the interstellar medium refract and diffract radio waves along multiple paths, resulting in angular and temporal broadening of radio pulses that limits pulsar timing precision. We determine multifrequency, multiepoch scat…

The NANOGrav 12.5 yr Data Set: Probing Interstellar Turbulence and Precision Pulsar Timing with PSR J1903+0327 Open

Abra Geiger, James M. Cordes, Michael T. Lam, Stella Koch Ocker, Shami Chatterjee , et al. · 2025

Free electrons in the interstellar medium refract and diffract radio waves along multiple paths, resulting in angular and temporal broadening of radio pulses that limits pulsar timing precision. We determine multifrequency, multiepoch scat…

Discovery and Localization of the Swift-Observed FRB 20241228A in a Star-forming Host Galaxy Open

Alice P. Curtin, Shion Andrew, Sunil Simha, Alice Cai, Kenzie Nimmo , et al. · 2025

On 2024 December 28, CHIME/FRB detected the thus-far non-repeating FRB 20241228A with a real-time signal-to-noise ratio of $>50$. Approximately 112~s later, the X-ray Telescope onboard the Neil Gehrels Swift Observatory was on source, the …

Searching for Historical Extragalactic Optical Transients Associated with Fast Radio Bursts Open

Y. Dong, C. D. Kilpatrick, W Fong, Alice P. Curtin, S. Opoku , et al. · 2025

We present a systematic search for past supernovae (SNe) and other historical optical transients at the positions of fast radio burst (FRB) sources to test FRB progenitor systems. Our sample comprises 83 FRBs detected by the Canadian Hydro…

The NANOGrav 15-Year Data Set: A Case Study for Simplified Dispersion Measure Modeling for PSR J1455-3330 and the Impact on Gravitational Wave Sensitivity Open

Michael T. Lam, D. L. Kaplan, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald , et al. · 2025

Evidence for a low-frequency gravitational-wave background using pulsar timing arrays has generated recent interest into its underlying contributing sources. However, multiple investigations have seen that the significance of the evidence …

The CHIME/FRB Discovery of the Extremely Active Fast Radio Burst Source FRB 20240114A Open

Kaitlyn Shin, Alice P. Curtin, Maxwell Fine, Ayush Pandhi, Shion Andrew , et al. · 2025

Among the thousands of observed fast radio bursts (FRBs), a few sources exhibit exceptionally high burst activity observable by many telescopes across a broad range of radio frequencies. Almost all of these highly active repeaters have bee…

The NANOGrav 15 yr Data Set: Harmonic Analysis of the Pulsar Angular Correlations Open

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, J. G. Baier , et al. · 2025

Pulsar timing array observations have found evidence for an isotropic gravitational-wave background with the Hellings–Downs angular correlations between pulsar pairs. This interpretation hinges on the measured shape of the angular correlat…

Pulse Profile Variability of PSR J1022+1001 in NANOGrav Data Open

William Fiore, M. A. McLaughlin, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald , et al. · 2025

Pulse profile stability is a central assumption of standard pulsar timing methods. Thus, it is important for pulsar timing array experiments such as the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) to account for…

The Anomalous Acceleration of PSR J2043+1711: Long-period Orbital Companion or Stellar Flyby? Open

Thomas Donlon, Sukanya Chakrabarti, Michael T. Lam, Daniel Huber, Daniel Hey , et al. · 2025

Based on the rate of change of its orbital period, PSR J2043+1711 has a substantial peculiar acceleration of 3.5 ± 0.8 mm s –1 yr –1 , which deviates from the acceleration predicted by equilibrium Milky Way (MW) models at a 4 σ level. The …

A Lower Mass Estimate for PSR J0348+0432 Based on CHIME/Pulsar Precision Timing Open

Alexander Saffer, Emmanuel Fonseca, S. M. Ransom, I. H. Stairs, Ryan S. Lynch , et al. · 2025

The binary pulsar J0348+0432 was previously shown to have a mass of approximately 2 M ⊙ , based on the combination of radial-velocity and model-dependent mass parameters derived from high-resolution optical spectroscopy of its white-dwarf …

Polarization Properties of 28 Repeating Fast Radio Burst Sources with CHIME/FRB Open

Cherry Ng, Ayush Pandhi, Ryan Mckinven, Alice P. Curtin, Kijung Shin , et al. · 2025

As part of the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) project, we report 41 new rotation measures (RMs) from 20 repeating fast radio bursts (FRBs) obtained between 2019 and 2023 for which no previous RM…

The NANOGrav 15-year Data Set: Search for Gravitational Wave Memory Open

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, J. G. Baier , et al. · 2025

We present the results of a search for nonlinear gravitational wave memory in the NANOGrav 15-year data set. We find no significant evidence for memory signals in the dataset, with a maximum Bayes factor of 3.1 in favor of a model includin…

A Catalog of Local Universe Fast Radio Bursts from CHIME/FRB and the KKO Outrigger Open

M. Amiri, Daniel Amouyal, Bridget C. Andersen, Shion Andrew, Kevin Bandura , et al. · 2025

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 …

Emmanuel Fonseca YOU? Author Swipe