S. J. Smartt
A5071206727- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Distributed and Parallel Computing Systems
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Spacecraft and Cryogenic Technologies
- Astronomical Observations and Instrumentation
- Scientific Computing and Data Management
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Particle Accelerators and Free-Electron Lasers
- Adaptive optics and wavefront sensing
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Neutrino Physics Research
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Non-Destructive Testing Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Particle physics theoretical and experimental studies
University of Oxford
2023-2025
Queen's University Belfast
2015-2024
Osservatorio Astronomico di Padova
2008-2022
University of Turku
2022
Osservatorio Astrofisico di Catania
2022
National Institute for Astrophysics
2008-2018
Astronomical Observatory of Capodimonte
2018
Astronomical Observatory of Rome
2018
Queens University
2010-2017
European Southern Observatory
2009-2010
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...
Knowledge of the progenitors core-collapse supernovae is a fundamental component in understanding explosions. The recent progress finding such stars reviewed. minimum initial mass that can produce supernova has converged to 8 +/- 1 solar masses, from direct detections red supergiant II-P SNe and most massive white dwarf progenitors, although this value model dependent. It appears type Ibc arise moderate interacting binaries. highly energetic, broad-lined Ic are likely produced by massive,...
We present the results of a 10.5-yr, volume-limited (28-Mpc) search for supernova (SN) progenitor stars. In doing so we compile all SNe discovered within this volume (132, which 27 per cent are Type Ia) and determine relative rates each subtype from literature studies. The core-collapse break down into 59 II-P 29 Ib/c, with remainder being IIb (5 cent), IIn (4 cent) II-L (3 cent). There have been 20 high-quality optical or near-infrared pre-explosion images that allow meaningful five cases...
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...
Abstract Over the last 15 years, supernova community has endeavoured to directly identify progenitor stars for core-collapse supernovae discovered in nearby galaxies. These precursors are often visible as resolved high-resolution images from space-and ground-based telescopes. The discovery rate of is limited by local and availability depth archive galaxies, with 18 detections precursor objects 27 upper limits. This review compiles these results (from 1999 2013) a distance-limited sample...
In the past decade, several rapidly evolving transients have been discovered whose timescales and luminosities are not easily explained by traditional supernovae (SNe) models. The sample size of these objects has remained small due, at least in part, to challenges detecting short timescale with survey cadences. Here we present results from a search within Pan-STARRS1 Medium Deep Survey (PS1-MDS) for luminous transients. We identify 10 new time above half-maximum (t1/2) less than 12 days...
High-quality collections of Type II supernova (SN) light curves are scarce because they evolve for hundreds days, making follow-up observations time consuming and often extending over multiple observing seasons. In these difficulties, the diversity SNe is not fully understood. Here we present ultraviolet optical photometry 12 monitored by Las Cumbres Observatory Global Telescope Network during 2013 to 2014, compare them with previously studied having well-sampled curves. We explore SN...
The progenitors of many type II core-collapse supernovae have now been identified directly on pre-discovery imaging. Here we present an extensive search for the Ibc in all available imaging since 1998. There are 12 with no detections either deep ground-based or Hubble Space Telescope archival deepest absolute BVR magnitude limits between -4 and -5. We compare these observed Wolf-Rayet population Large Magellanic Cloud estimate a 16 per cent probability failed to detect such progenitor by...
We report the results of a three-year-long dedicated monitoring campaign restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and spectroscopically optical near-infrared domains. monitored number erupting episodes past few years, increased density our observations during eruptive episodes. In this paper, we present full historical data set from 2009 to 2012 with multi-wavelength dense coverage two high-luminosity events between August...
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 VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30 Doradus region Magellanic Cloud (LMC). Here we introduce our scientific motivations and give overview survey targets, including near-infrared photometry comprehensive details data reduction. One principal objectives was to detect binary systems via variations their radial velocities, thus shaping observing strategy. Spectral classifications...
The detection of the binary neutron star GW170817 together with observation electromagnetic counterparts across entire spectrum inaugurated a new era multi-messenger astronomy. In this study we incorporate wavelength-dependent opacities and emissivities calculated from atomic-structure data enabling us to model both measured lightcurves spectra transient AT2017gfo. Best-fits observational are obtained by Gaussian Process Regression, which allows present posterior samples for kilonova source...
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 the ATLAS discovery and initial analysis of first 18 days unusual transient event, ATLAS18qqn/AT2018cow. It is characterized by a high peak luminosity ($\sim$1.7 $\times$ 10$^{44}$ erg s$^{-1}$), rapidly evolving light curves ($>$5 mag rise to in $\sim$3.5 days), hot blackbody spectra, peaking at $\sim$27000 K that are relatively featureless unchanging over two weeks. The bolometric curve cannot be powered radioactive decay under realistic assumptions. detection high-energy...
The mergers of binary compact objects such as neutron stars and black holes are central interest to several areas astrophysics, including the progenitors gamma-ray bursts (GRBs), sources high-frequency gravitational waves likely production sites for heavy element nucleosynthesis via rapid capture (the r-process). These elements include some great geophysical, biological cultural importance, thorium, iodine gold. Here we present observations exceptionally bright burst GRB 230307A. We show...
Abstract We present UV and/or optical observations and models of SN 2023ixf, a type II supernova (SN) located in Messier 101 at 6.9 Mpc. Early time ( flash ) spectroscopy obtained primarily Lick Observatory, reveals emission lines H i , He i/ii C iv N iii/iv/v with narrow core broad, symmetric wings arising from the photoionization dense, close-in circumstellar material (CSM) around progenitor star prior to shock breakout. These electron-scattering broadened line profiles persist for ∼8 days...