A5059586242- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Neutrino Physics Research
- Astrophysics and Star Formation Studies
- SAS software applications and methods
- Adaptive optics and wavefront sensing
- Optical Systems and Laser Technology
- Laser-Plasma Interactions and Diagnostics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Geophysics and Gravity Measurements
- Nuclear Physics and Applications
- Calibration and Measurement Techniques
- Spectroscopy and Chemometric Analyses
- Solar and Space Plasma Dynamics
- Particle Detector Development and Performance
- Gun Ownership and Violence Research
- Radio Astronomy Observations and Technology
- Fluid Dynamics and Turbulent Flows
Royal Holloway University of London
2025
University of Sheffield
2015-2024
Queen's University Belfast
2011-2015
University of Copenhagen
2009-2014
Royal Society
2012-2013
ARC Centre of Excellence for All-sky Astrophysics
2013
University of California, Santa Cruz
2009-2011
Centre for Cosmology and Particle Physics Phenomenology
2011
The University of Texas at Austin
2006-2009
Texas A&M University
2009
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...
(Abridged). We present a sample of 77 optical afterglows (OAs) Swift detected GRBs for which spectroscopic follow-up observations have been secured. provide linelists and equivalent widths all lines redward Ly-alpha. discuss to what extent the current bursts with OA spectroscopy is biased subsample GRBs. For that purpose we define an X-ray selected optimal conditions ground-based follow up from period March 2005 September 2008; 146 fulfill our criteria. derive redshift distribution this...
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...
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 results of one-year long observational campaign type II plateau SN 2005cs, which exploded in nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes 2005cs best observed low-luminosity, 56Ni-poor event so far and one core-collapse supernovae ever. The optical near-infrared spectra show narrow P-Cygni lines characteristic this family, are indicative a very low expansion velocity (about 1000 km s−1) ejected material. light curves cover both phase late-time...
Abstract We present early photometric and spectroscopic observations of SN 2013ej, a bright Type IIP supernova (SN) in M74. 2013ej is one the closest SNe ever discovered. The available archive images discovery help to constrain nature its progenitor. earliest detection this explosion was on 2013 July 24.125 ut our monitoring with FLOYDS spectrographs began 27.7 ut, continuing almost daily for two weeks. Daily optical achieved 1 m telescopes Las Cumbres Observatory Global Telescope (LCOGT)...
We present the detection of putative progenitor Type IIb SN 2011dh in archival pre-explosion Hubble Space Telescope images. Using post-explosion Adaptive Optics imaging with Gemini NIRI+ALTAIR, position supernova (SN) images was determined to within 23 mas. The candidate is consistent an F8 supergiant star (logL/L☉ = 4.92 ± 0.20 and Teff 6000 280 K). Through comparison stellar evolution tracks, this corresponds a single at end core C-burning initial mass MZAMS 13 3 M☉. possibility source...
We have initiated a survey using the newly commissioned X-shooter spectrograph to target candidate relatively metal-rich damped Lyman-alpha absorbers (DLAs). The spectral coverage of allows us search for not only emission, but also rest-frame optical emission lines. chosen DLAs where strongest lines ([OII], [OIII], Hbeta and Halpha) fall in NIR atmospheric transmission bands. In this first paper resulting from survey, we report on discovery galaxy counterpart z_abs = 2.354 DLA towards...
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....
Cao et al. (2013) reported a possible progenitor detection for the type Ib supernovae iPTF13bvn first time. We find that is in fact brighter than magnitudes previously by approximately 0.7 to 0.2 mag with larger error bluer filters. compare our new large set of binary evolution models and many initial masses range 10 20M(Sun) match this photometry other constraints suggested from analysing supernova. In addition these lower mass stars retain more helium at end model indicating they are...
We report and discuss post-explosion observations of supernova iPTF13bvn. find that the brightness SN at +740 days is below level pre-explosion source thus confirm progenitor star has gone. estimate late-time still dominated by supernova, which constrains magnitude mass a possible companion to approximately 10Msun. In turn this implies progenitor's initial constrained narrow range between 10 12Msun. The iPTF13bvn would have been helium giant rather than Wolf-Rayet star. addition, we suggest...
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 We present observations of SN 2021csp, the second example a newly identified type supernova (SN) hallmarked by strong, narrow, P Cygni carbon features at early times (Type Icn). The appears as fast and luminous blue transient times, reaching peak absolute magnitude −20 within 3 days due to strong interaction between ejecta ( v ≈ 30,000 km s −1 ) massive, dense, fast-moving C/O wind shed WC-like progenitor months before explosion. narrow-line disappear from spectrum 10–20 after...
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 As one of the closest supernovae (SNe) in last decade, SN 2023ixf is an unprecedented target to investigate progenitor star that exploded. However, there still significant uncertainty reported properties. In this work, we present a detailed study 2023ixf’s with two independent analyses. We first modeled its spectral energy distribution (SED) based on Hubble Space Telescope optical, Spitzer mid-infrared (IR), and ground-based near-IR data. find stellar pulsation circumstellar...
Abstract We present JWST near-infrared (NIR) and mid-infrared (MIR) spectroscopic observations of the nearby normal Type Ia supernova (SN) SN 2021aefx in nebular phase at +255 days past maximum light. Our Near Infrared Spectrograph (NIRSpec) Mid Instrument observations, combined with ground-based optical data from South African Large Telescope, constitute first complete optical+NIR+MIR spectrum covering 0.3–14 μ m. This unveils previously unobserved 2.5−5 m region, revealing strong iron...
Abstract To date, SN 2017ein is the only Type Ic supernova with a directly identified progenitor candidate. This candidate points to very massive (>45 M ⊙ ) Wolf–Rayet (WR) progenitor, but its disappearance after explosion of remains unconfirmed. In this work, we revisit in late-time images acquired by Hubble Space Telescope at 2.4–3.8 yr peak brightness. We find source has not disappeared, and brightness color remain almost same as preexplosion images. Thus, conclude that genuine...
We present the discovery of a red supergiant star that exploded as supernova 2003gd in nearby spiral galaxy M74. The Hubble Space Telescope (HST) and Gemini imaged this 6 to 9 months before explosion, subsequent HST images confirm positional coincidence with single resolved is 8(+4)(-2) solar masses. This confirms both stellar evolution models theories predicting cool supergiants are immediate progenitor stars type II-plateau supernovae.
The progenitor of SN 2005cs, in the galaxy M51, is identified pre-explosion HST ACS WFC imaging. Differential astrometry, with post-explosion HRC F555W images, permitted identification an accuracy 0.006". was detected F814W image I=23.3+/-0.2, but below detection thresholds F435W and B<24.8 V<25 at 5-sigma. Limits were also placed on U R band fluxes from WFPC2 F336W F675W images. Deep images infra-red NIRI Gemini-North telescope taken 2 months prior to explosion, not clearly these. upper...
Using images from the Hubble Space Telescope and Gemini Telescope, we confirmed disappearance of progenitors two type II supernovae (SNe) evaluated presence other stars associated with them. We found that progenitor SN 2003gd, an M-supergiant star, is no longer observed at location determined its intrinsic brightness using image subtraction techniques. The 1993J, a K-supergiant also present, but B-supergiant binary companion still observed. confirms these were produced by red supergiants.
[Abridged]. Here, we report on the discovery of galaxy counterpart z_abs=2.58 DLA line-of-sight to z=3.07 quasar SDSS J091826.16+163609.0. The is detected in OIII 5007 and OII 3726,3729 emission lines redshifted into NIR at an impact parameter 16 kpc. Ly-alpha not detected. upper limit implies that from this suppressed by more than order magnitude. amongst most metal-rich DLAs studied so far comparable redshifts. We find evidence for substantial depletion refractory elements onto dust...