A5059837212- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Advanced machining processes and optimization
- Astro and Planetary Science
- Advanced Machining and Optimization Techniques
- Stellar, planetary, and galactic studies
- Noise Effects and Management
- Galaxies: Formation, Evolution, Phenomena
- Vehicle Noise and Vibration Control
- Mechanics and Biomechanics Studies
- Hydraulic and Pneumatic Systems
- Robotic Mechanisms and Dynamics
- Nuclear Physics and Applications
- Adhesion, Friction, and Surface Interactions
- Retinal and Optic Conditions
- Gear and Bearing Dynamics Analysis
- Astronomy and Astrophysical Research
- Particle Accelerators and Free-Electron Lasers
- Human-Automation Interaction and Safety
- Vehicle emissions and performance
- Mechanical and Thermal Properties Analysis
- Manufacturing Process and Optimization
- Testicular diseases and treatments
Queen's University Belfast
2022-2024
Queen's University
1990-2024
University College London
2022
Pontifical Catholic University of Peru
2020
Health and Human Development (2HD) Research Network
2012
University of Windsor
1980
Abstract Fast X-ray transients (FXTs) are extragalactic bursts of X-rays first identified in archival data and now routinely discovered real time by the Einstein Probe, which is continuously surveying night sky soft (0.5–4 keV) regime. In this Letter, we report discovery second optical counterpart (AT 2024gsa) to an FXT (EP 240414a). EP 240414a located at a projected radial separation 27 kpc from its likely host galaxy z = 0.4018 ± 0.0010. The light curve AT 2024gsa displays three distinct...
We present extensive optical photometry of the afterglow GRB~221009A. Our data cover $0.9 - 59.9$\,days from time \textit{Swift} and \textit{Fermi} GRB detections. Photometry in $rizy$-band filters was collected primarily with Pan-STARRS supplemented by multiple 1- to 4-meter imaging facilities. analyzed Swift X-ray found a single decline rate power-law $f(t) \propto t^{-1.556\pm0.002}$ best describes light curve. In addition high foreground Milky Way dust extinction along this line sight,...
Abstract Fast X-ray Transients (FXTs) are extragalactic bursts of soft X-rays first identified ≳10 yr ago. Since then, nearly 40 events have been discovered, although almost all these recovered from archival Chandra and XMM-Newton data. To date, optical sky surveys follow-up searches not revealed any multiwavelength counterparts. The Einstein Probe, launched in 2024 January, has started surveying the regime (0.5–4 keV) will rapidly increase sample FXTs discovered real time. Here we report...
ABSTRACT GW190425 is the second of two binary neutron star (BNS) merger events to be significantly detected by Laser Interferometer Gravitational Wave (GW) Observatory (LIGO), Virgo and Kamioka (KAGRA) detector network. With a detection only in LIGO Livingston, skymap containing source was large no plausible electromagnetic counterpart found real-time searching 2019. Here, we summarize Asteroid Terrestrial-Impact Last Alert System (ATLAS) Panoramic Survey Telescope Rapid Response...
Abstract We present observations and analysis of the hostless luminous Type Ia supernova 2022ilv, illustrating it is part 2003fg-like family, often referred to as super-Chandrasekhar (Ia-SC) explosions. The Asteroid Terrestrial-impact Last Alert System light curve shows evidence a short-lived, pulse-like early excess, similar that detected in another (SN 2020hvf). broad, spectra are remarkably those SN 2009dc. Adopting redshift z = 0.026 ± 0.005 for 2022ilv based on spectral matching, our...
We report on our study of supernova (SN) 2022xxf based observations obtained during the first four months its evolution. The light curves (LCs) display two humps similar maximum brightness separated by 75 days, unprecedented for a broad-lined (BL) Type Ic (SN IcBL). SN is most nearby IcBL to date (in NGC 3705, $z = 0.0037$, at distance about 20 Mpc). Optical and near-infrared photometry spectroscopy are used identify energy source powering LC. Nearly 50 epochs high signal-to-noise-ratio were...
Abstract We present the discovery and extensive follow-up of a remarkable fast-evolving optical transient, AT 2022aedm, detected by Asteroid Terrestrial impact Last Alert Survey (ATLAS). In ATLAS o band, 2022aedm exhibited rise time 9 ± 1 days, reaching luminous peak with M g ≈ −22 mag. It faded 2 mag in band during next 15 days. These timescales are consistent other rapidly evolving transients, though luminosity is extreme. Most surprisingly, host galaxy massive elliptical negligible...
Quasi-periodic eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei galaxies, repeating on timescales hours to weeks
ABSTRACT Known for their efficiency in analysing large data sets, machine learning-based classifiers have been widely used wide-field sky survey pipelines. The upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will generate millions real-time alerts every night, enabling the discovery samples rare events. Identifying such objects soon after explosion be essential to study evolution. Using ∼5400 transients from Zwicky Transient Facility (ZTF) Bright as training test...
We present photometric and spectroscopic observations of two hydrogen-poor superluminous supernovae (SLSNe-I) at z = 0.4296 0.3103, respectively, which show an additional set broad Mg II absorption lines, blueshifted by a few thousands kilometer second^-1 with respect to the host galaxy system. Previous work interpreted this as due resonance line scattering SLSN continuum rapidly expanding circumstellar material (CSM) expelled shortly before explosion. The peak rest-frame g-band magnitude is...
Abstract Most stripped-envelope supernova progenitors are thought to be formed through binary interaction, losing hydrogen and/or helium from their outer layers. Ultrastripped supernovae an emerging class of transient that expected produced envelope stripping by a neutron star companion. However, relatively few examples known, and the outcomes such systems can diverse poorly understood at present. Here we present spectroscopic observations high-cadence, multiband photometry SN 2023zaw,...
This study aims to describe the grading methods and baseline characteristics for UK Biobank (UKBB) participants who underwent retinal imaging in 2009-2010, characterise individuals with features suggestive of age-related macular degeneration (AMD), glaucoma retinopathy.Non-mydriatic colour fundus photographs optical coherence tomography (OCT) scans were manually graded by Central Administrative Research Facility certified graders quality assured clinicians Network Ophthalmic Reading Centres...
We present photometric and spectroscopic observations of the Type Icn supernova (SN) 2021ckj. This rare type SNe is characterized by a rapid evolution high peak luminosity as well narrow lines highly ionized carbon at early phases, implying an interaction with hydrogen- helium-poor circumstellar matter (CSM). SN 2021ckj reached brightness ∼ − 20 mag in optical bands, rise time above half maximum ∼4 ∼10 days, respectively, g cyan bands. These features are reminiscent those other (SNe 2019hgp,...
ABSTRACT We present observations from X-ray to mid-infrared wavelengths of the most energetic non-quasar transient ever observed, AT2021lwx. Our data show a single optical brightening by factor >100 luminosity 7 × 1045 erg s−1 and total radiated energy 1.5 1053 erg, both greater than any known transient. The decline is smooth exponential ultraviolet–optical spectral distribution resembles blackbody with temperature 1.2 104 K. Tentative detections indicate secondary mode emission,...
Abstract We present multiwavelength photometry and spectroscopy of SN 2022jli, an unprecedented Type Ic supernova discovered in the galaxy NGC 157 at a distance ≈ 23 Mpc. The multiband light curves reveal many remarkable characteristics. Peaking magnitude g = 15.11 ± 0.02, high-cadence reveals periodic undulations 12.5 0.2 days superimposed on 200-day decline. This periodicity is observed from nine separate filter instrument configurations with peak-to-peak amplitudes ≃ 0.1 mag. first time...
ABSTRACT We present a pan-chromatic study of AT2017bcc, nuclear transient that was discovered in 2017 within the skymap reported burst-like gravitational-wave candidate, G274296. It initially classified as superluminous supernova, and then reclassified candidate tidal disruption event. Its optical light curve has since shown ongoing variability with structure function consistent an active galactic nucleus, however, earlier data show no for at least 10 yr prior to outburst 2017. The spectrum...
Abstract We present optical photometric and spectroscopic observations of the 02es-like type Ia supernova (SN) 2022ywc. The transient occurred in outskirts an elliptical host galaxy showed a striking double-peaked light curve with early excess feature detected ATLAS orange cyan bands. is remarkably luminous absolute magnitude ∼ − 19, comparable luminosity to subsequent radioactively driven second peak. spectra resemble hybrid SN 2016jhr, which considered be helium shell detonation candidate....
In this paper, a neural network based system for ‘on-line’ estimation of tool wear in turning operations is introduced. The monitors the cutting force components and extracts information from changes occurring over process. A hierarchical structure using multilayered feedforward static dynamic networks used as specialized subsystem, each component to be monitored. These subsystems share about they are monitoring their error estimating update networks. adaptability property ensures that...
SN\,2020zbf is a hydrogen-poor superluminous supernova (SLSN) at $z = 0.1947$ that shows conspicuous \ion{C}{II} features early times, in contrast to the majority of H-poor SLSNe. Its peak magnitude $M_{\rm g}$ $-21.2$~mag and its rise time ($\lesssim 26.4$ days from first light) places among fastest rising type I We used spectra taken ultraviolet (UV) near-infrared wavelengths identify spectral features. paid particular attention lines as they present distinctive characteristics when...