A5090201337- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- graph theory and CDMA systems
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Coding theory and cryptography
- Finite Group Theory Research
- Neutrino Physics Research
- Advanced Power Generation Technologies
- Particle Detector Development and Performance
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Planetary Science and Exploration
- Cosmology and Gravitation Theories
- Experimental Learning in Engineering
- X-ray Spectroscopy and Fluorescence Analysis
- Particle Accelerators and Free-Electron Lasers
- Mathematics Education and Teaching Techniques
- Topological and Geometric Data Analysis
- Molecular Spectroscopy and Structure
Queen's University Belfast
2016-2025
University of Oxford
2025
Huntsville Hospital
2024
Sam Houston State University
2008-2024
South African Radio Astronomy Observatory
2024
Astronomical Observatory
2024
Cerro Tololo Inter-American Observatory
2024
Royal Society for the Protection of Birds
2023
University of the Virgin Islands
2023
United States Virgin Islands Department of Health
2023
We present optical light curves, redshifts, and classifications for 365 spectroscopically confirmed Type Ia supernovae (SNe Ia) discovered by the Pan-STARRS1 (PS1) Medium Deep Survey. detail improvements to PS1 SN photometry, astrometry calibration that reduce systematic uncertainties in distances. combine subset of 279 ($0.03 < z 0.68$) with useful distance estimates from SDSS, SNLS, various low-z HST samples form largest combined sample consisting a total 1048 ranging $0.01 2.3$, which we...
We present the fifth release of UMIST Database for Astrochemistry (UDfA). The new reaction network contains 6173 gas-phase reactions, involving 467 species, 47 which are to this release. have updated rate coefficients across all types. included 1171 anion reactions and reviewed photorates. In addition usual network, we also now include, download, state-specific deuterated coefficients, deuterium exchange a list surface binding energies many neutral species. Where possible, referenced...
We report extensive observational data for five of the lowest redshift Super-Luminous Type Ic Supernovae (SL-SNe Ic) discovered to date, namely PTF10hgi, SN2011ke, PTF11rks, SN2011kf and SN2012il. Photometric imaging transients at +50 +230 days after peak combined with host galaxy subtraction reveals a luminous tail phase four these SL-SNe. A high resolution, optical near infrared spectrum from xshooter provides detection broad He I $\lambda$10830 emission line in (+50d) SN2012il, revealing...
We present optical spectroscopy and optical/near-IR photometry of 31 host galaxies hydrogen-poor superluminous supernovae (SLSNe), including 15 events from the Pan-STARRS1 Medium Deep Survey. Our sample spans redshift range 0.1 ≲ z 1.6, is first comprehensive galaxy study this specific subclass cosmic explosions. Combining multi-band emission-line measurements, we determine luminosities, stellar masses, star formation rates, metallicities. find that, as a whole, hosts SLSNe are...
Technology has advanced to the point that it is possible image entire sky every night and process data in real time. The hardly static: many interesting phenomena occur, including variable stationary objects such as stars or QSOs, transient supernovae M dwarf flares, moving asteroids themselves. Funded by NASA, we have designed built a survey system for purpose of finding dangerous near-Earth (NEAs). This system, "Asteroid Terrestrial-impact Last Alert System" (ATLAS), been optimized produce...
The Asteroid Terrestrial impact Last Alert System (ATLAS) system consists of two 0.5m Schmidt telescopes with cameras covering 29 square degrees at plate scale 1.86 arcsec per pixel. Working in tandem, the routinely survey whole sky visible from Hawaii (above $\delta > -50^{\circ}$) every nights, exposing four times night, typically reaching $o < 19$ magnitude exposure when moon is illuminated and $c 19.5$ dark skies. Construction underway further units to be sited Chile South Africa which...
We present griz light curves of 146 spectroscopically confirmed Type Ia Supernovae ($0.03 < z <0.65$) discovered during the first 1.5 years Pan-STARRS1 Medium Deep Survey. The natural photometric system is determined by a combination on-site measurements instrument response function and observations spectrophotometric standard stars. find that systematic uncertainties in are currently 1.2\% without accounting for uncertainty HST Calspec definition AB system. A Hubble diagram constructed with...
The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. We describe the data reduction strategy and products which are publicly available through ESO archive Data Release 1 (SSDR1). PESSTO uses New Technology Telescope with EFOSC2 SOFI to provide optical NIR spectroscopy imaging. target supernovae transients brighter than 20.5mag for classification. Science targets then selected follow-up based on...
We present panchromatic observations and modeling of supernova (SN) 2020tlf, the first normal type II-P/L SN with confirmed precursor emission, as detected by Young Supernova Experiment transient survey Pan-STARRS1 telescope. Pre-explosion emission was in $riz-$bands at 130 days prior to 2020tlf persisted relatively constant flux until light. Soon after discovery, "flash" spectroscopy revealed prominent narrow symmetric lines ($v_w < 300$ km s$^{-1}$) that resulted from photo-ionization...
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...
Recent searches by unbiased, wide-field surveys have uncovered a group of extremely luminous optical transients. The initial discoveries SN 2005ap the Texas Supernova Search and SCP-06F6 in deep Hubble pencil beam survey were followed Palomar Transient Factory confirmation host redshifts for other similar transients share common properties high luminosities (peak magnitudes ∼−21 to −23), blue colors, lack H or He spectral features. physical mechanism that produces luminosity is uncertain,...
We present the Pan-STARRS1 discovery of long-lived and blue transient PS1-11af, which was also detected by Galaxy Evolution Explorer with coordinated observations in near-ultraviolet (NUV) band. PS1-11af is associated nucleus an early type galaxy at redshift z = 0.4046 that exhibits no evidence for star formation or active galactic activity. Four epochs spectroscopy reveal a pair broad absorption features UV on otherwise featureless spectra. Despite superficial similarity these to P-Cygni...
We assemble a sample of 24 hydrogen-poor super-luminous supernovae (SLSNe). Parameterizing the light curve shape through rise and decline timescales shows that two are highly correlated. Magnetar-powered models can reproduce correlation, with diversity in rates driven by diffusion timescale. Circumstellar interaction exhibit similar rise-decline relation, but only for narrow range densities, which may be problematic these models. find SLSNe approximately 3.5 magnitudes brighter have curves 3...
We present observations of SN 2015bn (= PS15ae = CSS141223-113342+004332 MLS150211-113342+004333), a Type I superluminous supernova (SLSN) at redshift $z=0.1136$. As well as being one the closest SLSNe yet discovered, it is intrinsically brighter ($M_U\approx-23.1$) and in fainter galaxy ($M_B\approx-16.0$) than other $z\sim0.1$. used this opportunity to collect most extensive dataset for any SLSN date, including densely-sampled spectroscopy photometry, from UV NIR, spanning $-$50 +250 days...
We present optical spectra and light curves for three hydrogen-poor superluminous supernovae followed by the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). Time series spectroscopy from a few days after maximum to 100 d later shows them be fairly typical this class, with dominated Ca ii, Mg Fe Si which evolve slowly over most post-peak photospheric phase. determine bolometric apply simple fitting tools, based on diffusion energy input magnetar spin-down, 56Ni decay, collision...
We present optical and near-infrared (NIR) photometry spectroscopy of the Type IIb supernova (SN) 2011dh for first 100 days. complement our extensive dataset with SWIFT ultra-violet (UV) Spitzer mid-infrared (MIR) data to build a UV MIR bolometric lightcurve using both photometric spectroscopic data. Hydrodynamical modelling SN based on this have been presented in Bersten (2012). find that absorption minimum hydrogen lines is never seen below ~11000 km/s but approaches value as get weaker....
We probe the systematic uncertainties from 113 Type Ia supernovae (SNIa) in Pan-STARRS1 (PS1) sample along with 197 SN a combination of low-redshift surveys. The companion paper by Rest et al. (2013) describes photometric measurements and cosmological inferences PS1 sample. largest uncertainty stems calibration low-z samples. increase observed Calspec standards 7 to 10 used define system. SDSS-II systems are compared discrepancies up ~0.02 mag recovered. find proper way treat intrinsic...
We present ultraviolet, optical and near-infrared observations of the interacting transient SN 2009ip, covering period from start outburst in 2012 October until end observing season. The reached a peak magnitude MV = −17.7 mag, with total integrated luminosity 1.9 × 1049 erg over August–December. light curve fades rapidly, dropping by 4.5 mag V-band 100 d. spectra are dominated narrow emission lines broad electron scattering wings, signalling dense circumstellar environment, together...
The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely-calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. calibration of the current SN is largest component systematic uncertainties cosmology, new data are necessary make progress. We present motivation, survey design, observation strategy, implementation, first results Survey. using Pan-STARRS telescope obtain photometry up 800 SNe at z < 0.1. This strategy has several unique...
Hypervelocity stars (HVS) travel with velocities so high, that they exceed the escape velocity of Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, 2) is a compact helium star. Here we present spectroscopic and kinematic analysis US\,708. Travelling $\sim1200\,{\rm km\,s^{-1}}$, it fastest unbound star in our In reconstructing its trajectory, Galactic center becomes very unlikely as an origin, which hardly consistent most favored ejection mechanism for other...
We present observations and analysis of 18 stripped-envelope supernovae observed during 2013–2018. This sample consists five H/He-rich SNe, six H-poor/He-rich three narrow lined SNe Ic, four broad Ic. The peak luminosity characteristic time-scales the bolometric light curves are calculated, modelled to derive 56Ni ejecta masses (MNi Mej). Additionally, temperature evolution spectral line velocity each SN examined. Analysis [O i] in nebular phase eight suggests their progenitors had initial...