A. A. Breeveld
A5063448039- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- SAS software applications and methods
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Photocathodes and Microchannel Plates
- Inertial Sensor and Navigation
- Astrophysics and Star Formation Studies
- Atmospheric Ozone and Climate
- Advanced X-ray and CT Imaging
- Dark Matter and Cosmic Phenomena
- Statistical and numerical algorithms
- Spacecraft Design and Technology
- Infrared Target Detection Methodologies
- Underwater Acoustics Research
University College London
2015-2024
Centre for Alternative Technology
2024
UCL Australia
2006-2015
Pennsylvania State University
2015
Southwest Research Institute
2011-2015
Sapienza University of Rome
2015
Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo
2014-2015
Dorking Community Hospital
2011
Goddard Space Flight Center
2009-2011
Universities Space Research Association
2011
We present the photometric calibration of Swift UltraViolet/Optical Telescope (UVOT) which includes: optimum and background apertures, effective area curves, colour transformations, conversion factors for count rates to flux, zero points (which are accurate better than 4 per cent) each seven UVOT broadband filters. The was performed with observations standard stars star fields that represent a wide range spectral types. results include position dependent uniformity, instrument response over...
The XMM-OM instrument extends the spectral coverage of XMM-Newton observatory into ultraviolet and optical range. It provides imaging time-resolved data on targets simultaneously with observations in EPIC RGS. also has ability to track stars its field view, thus providing an improved post-facto aspect solution for spacecraft. An overview operation is given, together current information performance instrument.
With the first direct detection of merging black holes in 2015, era gravitational wave (GW) astrophysics began. A complete picture compact object mergers, however, requires an electromagnetic (EM) counterpart. We report ultraviolet (UV) and X-ray observations by Swift Nuclear Spectroscopic Telescope ARray (NuSTAR) EM counterpart binary neutron star merger GW170817. The bright, rapidly fading emission indicates a high mass ($\approx0.03$ solar masses) wind-driven outflow with moderate...
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...
The Ultraviolet/Optical Telescope (UVOT) is one of three instruments onboard the Swift observatory. photometric calibration has been published, and this paper follows up with details on other aspects including a measurement point spread function an assessment orbital variation effect photometry. A correction for large-scale variations in sensitivity over field view described, as well model coincidence loss which used to assess extended regions. We have provided detector distortion measured...
Recent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and X-rays. This is densest extended AGN continuum sampling ever obtained, with a mean rate <0.5 day. Approximately daily HST UV was also obtained. The light curves show strong correlations (r_max = 0.57 - 0.90) clearest measurement to date interband lags. These lags are well-fit by \tau propto \lambda^4/3 wavelength dependence, normalization that indicates...
ABSTRACT We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multiwavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in nine filters ( BVRI and ugriz ). Combined with ultraviolet the Hubble Space Telescope Swift , we confirm significant time delays between continuum bands as a function wavelength, extending wavelength coverage 1158 Å z band (~9160 Å). find that lags at wavelengths longer...
We present the observations of GRB090510 performed by Fermi Gamma-Ray Space Telescope and Swift observatory. This is a bright, short burst that shows an extended emission detected in GeV range. Furthermore, its optical initially rises, feature so far observed only long bursts, while X-ray flux initial shallow decrease, followed steeper decay. exceptional behavior enables us to investigate physical properties GRB outflow, poorly known bursts. discuss internal shock external models for...
Abstract Swift intensive accretion disk reverberation mapping of four AGN yielded light curves sampled ∼200–350 times in 0.3–10 keV X-ray and six UV/optical bands. Uniform reduction cross-correlation analysis these data sets yields three main results: (1) The X-ray/UV correlations are much weaker than those within the UV/optical, posing severe problems for lamp-post reprocessing model which variations a central corona drive power surrounding disk. (2) interband lags generally consistent with...
We describe the first results from a six-month long reverberation-mapping experiment in ultraviolet based on 170 observations of Seyfert 1 galaxy NGC 5548 with Cosmic Origins Spectrograph Hubble Space Telescope. Significant correlated variability is found continuum and broad emission lines, amplitudes ranging ~30% to factor two lines three continuum. The variations all strong lag behind those continuum, He II 1640 lagging by ~2.5 days Lyman alpha 1215, C IV 1550, Si 1400 ~5-6 days....
The bright transient AT2018cow has been unlike any other known type of transient. Its high brightness, rapid rise and decay initially nearly featureless spectrum are unprecedented difficult to explain using models for similar burst sources. We present evidence faint gamma-ray emission continuing at least 8 days, spectra in the ultraviolet bands -- both unusual eruptive X-ray variability source a burst-like character. UV-optical does not show CNO line but is well described by blackbody....
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...
We present the first statistical analysis of 27 UVOT optical/ultra-violet lightcurves GRB afterglows. have found, through in observer's frame, that a significant fraction rise 500s after trigger, all decay 500s, typically as power-law with relatively narrow distribution indices, and brightest optical afterglows tend to quickest. find could either be produced physically by start forward shock, when jet begins plough into external medium, or geometrically where an off-axis observer sees rising...
We present the first Swift Ultraviolet/Optical Telescope (UVOT) gamma-ray burst (GRB) afterglow catalog. The catalog contains data from over 64,000 independent UVOT image observations of 229 GRBs detected by Swift, High Energy Transient Explorer 2 (HETE2), International Gamma-Ray Astrophysics Laboratory (INTEGRAL), and Interplanetary Network (IPN). covers occurring during period 2005 January 17 to 2007 June 16 includes ∼86% bursts Burst Alert (BAT). provides detailed positional, temporal,...
We present an updated calibration of the Swift/UVOT broadband ultraviolet (uvw1, uvm2, and uvw2) filters. The new accounts for ~1% per year decline in UVOT sensitivity observed all filters, makes use additional sources with a wider range colours HST spectrophotometry. In this paper we effective area curves instrumental photometric zeropoints compare previous calibration.
The XMM-Newton Serendipitous Ultraviolet Source Survey (XMM-SUSS) is a catalogue of ultraviolet (UV) sources detected serendipitously by the Optical Monitor (XMM-OM) on-board observatory. contains ultraviolet-detected collected from 2,417 XMM-OM observations in 1-6 broad band UV and optical filters, made between 24 February 2000 29 March 2007. primary contents are source positions, magnitudes fluxes 1 to 6 passbands, these accompanied profile diagnostics variability statistics. XMM-SUSS...
We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part a larger multi-wavelength reverberation mapping campaign. The campaign spanned six months and achieved almost daily cadence with observations from five ground-based telescopes. H$\beta$ He II $\lambda$4686 broad emission-line light curves lag that 5100 $\AA$ continuum by $4.17^{+0.36}_{-0.36}$ days $0.79^{+0.35}_{-0.34}$ days, respectively. relative to 1158 ultraviolet curve measured Hubble Space...
ABSTRACT We present results of time-series analysis the first year Fairall 9 intensive disc-reverberation campaign. used Swift and Las Cumbres Observatory global telescope network to continuously monitor from X-rays near-infrared at a daily subdaily cadence. The cross-correlation function between bands provides evidence for lag spectrum consistent with τ ∝ λ4/3 scaling expected an optically thick, geometrically thin blackbody accretion disc. Decomposing flux into constant variable...