R. A. J. Eyles-Ferris
A5013333852- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- SAS software applications and methods
- Geophysics and Gravity Measurements
- Optical Systems and Laser Technology
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- Time Series Analysis and Forecasting
- Stellar, planetary, and galactic studies
- Statistical and numerical algorithms
- Inertial Sensor and Navigation
- Remote Sensing in Agriculture
- Gaussian Processes and Bayesian Inference
- Astro and Planetary Science
- Spectroscopy Techniques in Biomedical and Chemical Research
- High-pressure geophysics and materials
- Geochemistry and Geologic Mapping
- Laser-Plasma Interactions and Diagnostics
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
University of Leicester
2019-2024
Instituto de Astrofísica de Canarias
2024
Armagh Observatory & Planetarium
2024
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
ABSTRACT We report the results of optical follow-up observations 29 gravitational-wave (GW) triggers during first half LIGO–Virgo Collaboration (LVC) O3 run with Gravitational-wave Optical Transient Observer (GOTO) in its prototype 4-telescope configuration (GOTO-4). While no viable electromagnetic (EM) counterpart candidate was identified, we estimate our 3D (volumetric) coverage using test light curves on- and off-axis gamma-ray bursts kilonovae. In cases where source region observable...
ABSTRACT The Gravitational-wave Optical Transient Observer (GOTO) is an array of wide-field optical telescopes, designed to exploit new discoveries from the next generation gravitational wave detectors (LIGO, Virgo, and KAGRA), study rapidly evolving transients, multimessenger opportunities arising neutrino very high energy gamma-ray triggers. In addition a rapid response mode, will also perform sensitive, all-sky transient survey with few day cadence. facility features novel, modular design...
Abstract In recent years, searches of archival X-ray data have revealed galaxies exhibiting nuclear quasi-periodic eruptions with periods several hours. These are reminiscent the tidal disruption a star by supermassive black hole. The repeated, partial stripping white dwarf in an eccentric orbit around ~10 5 M ⊙ hole provides attractive model. A separate class periodic transients, much longer timescales, recently been discovered optically and may arise from main-sequence 7 No clear...
ABSTRACT We present the Living Swift-XRT Point Source (LSXPS) catalogue and real-time transient detector. This system allows us for first time to carry out low-latency searches new X-ray events fainter than those available current generation of wide-field imagers, report their detection in near real time. Previously, such could only be found delayed searches, e.g. archival data; our analysis now enables rapid ongoing follow-up these events, enabling probing time-scales previously...
Abstract The Einstein Probe (EP) achieved its first detection and localization of a bright X-ray flare, EP240219a, on 2024 February 19, during commissioning phase. Subsequent targeted searches triggered by the EP240219a alert identified faint, untriggered gamma-ray burst (GRB) in archived data Fermi Gamma-ray Burst Monitor (GBM), Swift Alert Telescope (BAT), Insight-HXMT/HE. EP Wide-field (WXT) light curve reveals long duration approximately 160 s with slow decay, whereas Fermi/GBM shows...
Context. Gravitational wave (GW) astronomy has rapidly reached maturity, becoming a fundamental observing window for modern astrophysics. The coalescences of few tens black hole (BH) binaries have been detected, while the number events possibly including neutron star (NS) is still limited to few. On 2019 August 14, LIGO and Virgo interferometers detected high-significance event labelled S190814bv. A preliminary analysis GW data suggests that was likely due merger compact binary system formed...
ABSTRACT Large-scale sky surveys have played a transformative role in our understanding of astrophysical transients, only made possible by increasingly powerful machine learning-based filtering to accurately sift through the vast quantities incoming data generated. In this paper, we present new real-bogus classifier based on Bayesian convolutional neural network that provides nuanced, uncertainty-aware classification transient candidates difference imaging, and demonstrate its application...
Compact binaries such as double neutron stars or a star paired with black-hole, are strong sources of gravitational waves during coalescence and also the likely progenitors various electromagnetic phenomena, notably short-duration gamma-ray bursts (SGRBs), kilonovae. In this work, we generate populations synthetic place them in galaxies from large-scale hydrodynamical galaxy evolution simulation EAGLE. With our zELDA code, seeded proportion to formation rate, follow their merger using both...
The advent of wide-field sky surveys has led to the growth transient and variable source discoveries. data deluge produced by these necessitated use machine learning (ML) deep (DL) algorithms sift through vast incoming stream. A problem that arises in real-world applications for classification is imbalanced data, where a class objects within underrepresented, leading bias over-represented classes ML DL classifiers. We present recurrent neural network (RNN) classifier takes photometric...
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
The amount of observational data produced by time-domain astronomy is exponentially in-creasing. Human inspection alone not an effective way to identify genuine transients fromthe data. An automatic real-bogus classifier needed and machine learning techniques are commonly used achieve this goal. Building a training set with sufficiently large number verified challenging, due the requirement human verification. We presentan approach for creating using all detections in science images be...
Abstract We report on the detection of candidate optical counterpart GOTO23akf/AT2023shv to GRB 230911A with Gravitational-wave Optical Transient Observer (GOTO) instruments located at La Palma, Canary Islands, and Siding Spring Observatory, Australia. The Fermi Gamma-ray Burst Monitor, which finds gamma-ray bursts (GRBs) nearly every two days, detected a statistical uncertainty 4.°1. However, large (∼10–100 deg 2 ) localization areas mostly impede rapid identification an counterpart. GOTO...
ABSTRACT A small fraction of candidate tidal disruption events (TDEs) show evidence powerful relativistic jets, which are particularly pronounced at radio wavelengths, and likely contribute non-thermal emission a wide range wavelengths. component can be diagnosed using linear polarimetry, even when the total received light is dominated by from an accretion disc or outflow. In this paper, we present Very Large Telescope (VLT) measurements polarization optical jetted TDE Swift J2058+0516. This...
The typical detection rate of $\sim1$ gamma-ray burst (GRB) per day by the \emph{Fermi} Gamma-ray Burst Monitor (GBM) provides a valuable opportunity to further our understanding GRB physics. However, large uncertainty localization typically prevents rapid identification multi-wavelength counterparts. We report follow-up 93 GRBs with Gravitational-wave Optical Transient Observer (GOTO) prototype on La Palma. selected 53 events (based favourable observing conditions) for detailed analysis,...
ABSTRACT We present simulated optical light curves of super-Eddington tidal disruption events (TDEs) using the ZEro-BeRnoulli Accretion (ZEBRA) flow model, which proposes that during phase, disc is quasi-spherical, radiation-pressure dominated, and accompanied by production strong jets. construct for both on- off-axis (with respect to jet) observers account anisotropic nature jetted emission. find at wavelengths, emission from accretion orders magnitude brighter than produced jet, even with...
Developing an effective automatic classifier to separate genuine sources from artifacts is essential for transient follow-ups in wide-field optical surveys. The identification of detections the subtraction after image differencing process a key step such classifiers, known as real-bogus classification problem. We apply self-supervised machine learning model, deep-embedded self-organizing map (DESOM) this "real-bogus" DESOM combines autoencoder and perform clustering order distinguish between...
Abstract The LIGO, Virgo and KAGRA (LVK) gravitational wave observatories are currently undertaking their O4 observing run offering the opportunity to discover new electromagnetic counterparts events. We examine capability of Neil Gehrels Swift Observatory (Swift) respond these triggers, primarily binary neutron star mergers, with both UV/Optical Telescope (UVOT) X-ray (XRT). simulate Swift’s response a trigger under different strategies using model skymaps, convolving 2MPZ catalogue produce...
Abstract We present the first release of Gravitational Wave AfterglowPy Analysis (GWAPA) webtool (Available at https://gwapa.web.roma2.infn.it/ ). GWAPA is designed to provide community with an interactive tool for rapid analysis gravitational wave afterglow counterparts and can be extended general case gamma-ray burst afterglows seen different angles. It based on afterglowpy package allows users upload observational data vary parameters infer properties explosion. Multiple jet structures,...
We present the first release of Gravitational Wave AfterglowPy Analysis (GWAPA) webtool. GWAPA is designed to provide community with an interactive tool for rapid analysis gravitational wave afterglow counterparts and can be extended general case gamma-ray burst afterglows seen at different angles. It based on afterglowpy package allows users upload observational data vary parameters infer properties explosion. Multiple jet structures, including top hat, Gaussian power laws, in addition a...
Gamma-ray bursts (GRBs) are traditionally classified as either short GRBs with durations $\lesssim 2$ s that powered by compact object mergers, or long $\gtrsim the deaths of massive stars. Recent results, however, have challenged this dichotomy and suggest there exists a population merger-driven bursts. One such example, GRB 191019A, has $t_{90} \approx 64$ but many its other properties -- including host galaxy, afterglow luminosity lack associated supernova more consistent GRB. Here we...
Abstract Gamma-ray bursts (GRBs) are traditionally classified as either short GRBs with durations ≲2 s that powered by compact object mergers or long ≳2 the deaths of massive stars. Recent results, however, have challenged this dichotomy and suggest there exists a population merger-driven bursts. One such example, GRB 191019A, has t 90 ≈ 64 s, but many its other properties—including host galaxy, afterglow luminosity lack associated supernova—are more consistent GRB. Here we propose an...