P. W. A. Roming
A5059034919- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- SAS software applications and methods
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Particle Detector Development and Performance
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Spacecraft Design and Technology
- CCD and CMOS Imaging Sensors
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
- Galaxies: Formation, Evolution, Phenomena
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Radio Astronomy Observations and Technology
- Science Education and Pedagogy
- Space Exploration and Technology
- Spacecraft and Cryogenic Technologies
Southwest Research Institute
2013-2024
The University of Texas at San Antonio
2015-2017
Pennsylvania State University
2007-2016
University College London
2008-2011
Goddard Space Flight Center
2011
Universities Space Research Association
2011
University of Leicester
2011
Trieste Astronomical Observatory
2010
National Institute for Astrophysics
2010
Saint Vincent College
2008
The Swift mission, scheduled for launch in 2004, is a multiwavelength observatory gamma-ray burst (GRB) astronomy. It first-of-its-kind autonomous rapid-slewing satellite transient astronomy and pioneers the way future rapid-reaction missions. will be far more powerful than any previous GRB observing 100 bursts yr-1 performing detailed X-ray UV/optical afterglow observations spanning timescales from 1 minute to several days after burst. objectives are (1) determine origin of GRBs, (2)...
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 double explosion of SN 2009ip in 2012 raises questions about our understanding the late stages massive star evolution. Here we present a comprehensive study during its remarkable rebrightenings. High-cadence photometric and spectroscopic observations from GeV to radio band obtained variety ground-based space facilities (including Very Large Array, Swift, Fermi, Hubble Space Telescope, XMM) constrain be low energy (E ∼ 1050 erg for an ejecta mass ∼0.5 M☉) asymmetric complex medium shaped...
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...
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,...
GRB 060614 is a remarkable gamma-ray burst (GRB) observed by Swift with puzzling properties, which challenge current progenitor models. In particular, the lack of any bright supernova (SN) down to very strict limits and vanishing spectral lags during whole are typical short GRBs, strikingly at odds long (102 s) duration this event. Here we present detailed temporal analysis observations 060614. We show that presents standard optical, ultraviolet X-ray afterglows, detected beginning 4 ks...
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 composition and amount of interstellar dust within gamma-ray burst (GRB) host galaxies is key importance when addressing selection effects in the GRB redshift distribution, studying properties their galaxies. As well as implications for research, probing high-z hosts GRBs also contributes to our understanding conditions medium star-formation distant Universe. Nevertheless, physical continues be a highly contended issue. In this paper we explore mean extinction sample 17 with total galaxy...
We present an extensive optical and near-infrared photometric spectroscopic campaign of the Type IIP supernova SN 2012aw. The data set densely covers evolution 2012aw shortly after explosion through end photospheric phase, with two additional observations collected during nebular to fit radioactive tail estimate 56Ni mass. Also included in our analysis is previously published Swift UV data, therefore providing a complete view ultraviolet-optical-infrared phase. On basis set, we all relevant...
The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from very earliest phases of burst. X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after burst, indicative jet break. This break time combined total energy constrains opening angle to be 3.2 degrees. We derive an empirical `time-lag' redshift BAT data z_hat = 0.69 +/- 0.02, in good agreement spectroscopic 0.61. Prior break,...
The Swift Gamma Ray Burst satellite routinely provides prompt positions for GRBs and their afterglows on timescales of a few hundred seconds. However, with pointing accuracy only arcminutes, systematic uncertainty the star-tracker solutions to World Coordinate System 3–4 arcsec, precision early XRT is limited arcsec at best. This significant because operationally, detects >95% all GRBs, while UVOT optically brightest bursts, ~30% bursts detected by BAT; thus accurate are important majority...
Using a sample of gamma-ray burst (GRB) afterglows detected by both the X-Ray Telescope (XRT) and UV/Optical (UVOT) on Swift, we modelled spectral energy distributions (SEDs) to determine gas column densities dust extinction in GRB local environment. In six out seven cases find an X-ray absorber associated with host galaxy density (assuming solar abundances) ranging from (0.8–7.7) × 1021 cm−2. We rest-frame visual AV using Small Magellanic Cloud (SMC), Large (LMC) Galactic curves model...
In this paper we present the results from analysis of a sample 28 gamma-ray burst (GRB) afterglow spectral energy distributions, spanning X-ray through to near-infrared wavelengths. This is largest GRB distributions thus far studied, providing strong handle on optical depth distribution soft absorption and dust-extinction systems in host galaxies. We detect an system within galaxy 79% sample, extinction 71% find Small Magellanic Cloud (SMC) law provide acceptable fit profile for majority...
We present the results from a multiwavelength campaign of powerful Gamma-ray quasar PKS 1510-089. This commenced with deep Suzaku observation lasting three days for total exposure time 120 ks, and continued Swift monitoring over 18 days. Besides observations, included ground-based optical radio data, yielded quasi-simultaneous broad-band spectral energy distribution 10^9 Hz to 10^{19} Hz. The provided high S/N X-ray spectrum, which is well represented by an extremely hard power-law photon...
The peculiar Type Ib supernova (SN) 2006jc has been observed with the UV/Optical Telescope (UVOT) and X-Ray (XRT) on board Swift observatory over a period of 19-183 days after explosion. Signatures interaction outgoing SN shock dense circumstellar material (CSM) are detected, such as strong X-ray emission (L0.2–10 > 1039 erg s−1) presence Mg II 2800 Å line visible in UV spectra. In combination Chandra observation obtained day 40 explosion, light curve is constructed, which shows unique rise...
Correlation studies of prompt and afterglow emission from gamma-ray bursts (GRBs) between different spectral bands have been difficult to do in the past because few had comprehensive comparable measurements. In this paper we present a large uniform data set for correlation analysis based on detected by Swift mission. For first time, short long can be analyzed compared. It is found both classes that optical, X-ray, are linearly correlated, but with spread about line; stronger tend brighter...
We present the entire sample of ultraviolet (UV) spectra supernovae (SNe) obtained with Ultraviolet/Optical Telescope (UVOT) on board Swift satellite during first two years observations (2005/2006). A total 29 UV-grism and 22 V-grism nine SNe have been collected, which six are thermonuclear (Type Ia) three core-collapse Ibc/II) SNe. All photospheric phase. After a comparison our those in literature (SNe 1992A, 1990N, 1999em), we confirm some degree diversity UV emission Type Ia greater...
The new and extreme population of gamma-ray bursts (GRBs) detected by the Fermi Large Area Telescope (LAT) shows several features in high-energy gamma rays that are providing interesting unexpected clues into GRB prompt afterglow emission mechanisms. Over last six years, it has been Swift provided robust data set UV/optical X-ray observations opened many windows components structure. relationship between LAT-detected GRBs well-studied, fainter, less energetic Burst Alert is only beginning to...
We present a study of the early (days to weeks) X-ray and UV properties eight Type Ia supernovae (SNe Ia) which have been extensively observed with X-Ray Telescope (XRT) UV/Optical (UVOT) onboard Swift, ranging from 5-132 days after outburst. SN 2005ke is tentatively detected (at 3-3.6 sigma level significance) in X-rays based on deep monitoring XRT 8 120 The inferred luminosity [(2+/-1) x 10^{38} ergs/s; 0.3-2 keV band] likely caused by interaction shock circumstellar material (CSM),...
Context.We present the results of a set observations nine TeV detected BL Lac objects performed by XRT and UVOT detectors on board Swift satellite between March December 2005.