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Papers by Patricia Boyd
Astronomische Gesellschaft Meeting Abstracts, 2000
Cultura organizacional y su importancia dentro de la formación en turismo 69 Cultura organizacion... more Cultura organizacional y su importancia dentro de la formación en turismo 69 Cultura organizacional y su importancia dentro de la formación en turismo Organizational culture and its importance within tourism Cultura organizacional e sua importância na formação em turismoçç
Il Nuovo Cimento B, 2006
Résumé/Abstract Swift unprecedented fast follow-up observations of gamma-ray bursts have allowed ... more Résumé/Abstract Swift unprecedented fast follow-up observations of gamma-ray bursts have allowed us to discover a new feature of GRB afterglows: a phase of shallow decay, usually attributed to energy injection in the burst ejecta, which can last for several thousands of ...
We focus on two systems. The first is the Be/X-ray binary Swift J1626.6-5156, discovered in outbu... more We focus on two systems. The first is the Be/X-ray binary Swift J1626.6-5156, discovered in outburst by the Swift Burst Alert Telescope (BAT) in December 2005. Monitoring by the Rossi X-ray Timing Explorer (RXTE) has revealed a 45-day quasi-period in its long-term light curve, one cycle of which was observed in near-simultaneity by the Swift UV/optical Telescope (UVOT) and X-Ray
The Astrophysical Journal, 2008
We present the first Swift Ultra-Violet/Optical Telescope (UVOT) gammaray burst (GRB) afterglow c... more We present the first Swift Ultra-Violet/Optical Telescope (UVOT) gammaray burst (GRB) afterglow catalog. The catalog contains data from over 64, 000 independent UVOT image observations of 229 GRBs first detected by Swift, the High Energy Transient Explorer 2 (HETE2), the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), and the Interplanetary Network (IPN). The catalog covers GRBs occurring during the period from 2005 Jan 17 to 2007 Jun 16 and includes ∼ 86% of the bursts detected by the Swift Burst Alert Telescope (BAT). The catalog provides detailed burst positional, temporal, and photometric information extracted from each of the UVOT images. Positions for bursts detected at the 3σ-level are provided with a nominal accuracy, relative to the USNO-B1 catalog, of ∼ 0. ′′ 25. Photometry for each burst is given in three UV bands, three optical bands, and a 'white' or open filter. Upper limits for magnitudes are reported for sources detected below 3σ. General properties of the burst sample and light curves, including the filter-dependent temporal slopes, are also provided. The majority of the UVOT light curves, for bursts detected at
The Astrophysical Journal, 1994
The Astrophysical Journal, 2006
We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray ba... more We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray bands by the Swift BAT and the Konus-Wind instruments of the short-hard burst, GRB 060313. The observations reveal multiple peaks in both the gamma-ray and hard X-ray bands suggesting a highly variable outflow from the central explosion. We also describe the early-time observations of the X-ray and UV/optical afterglows by the Swift XRT and UVOT instruments. The combination of the X-ray and UV/optical observations provides the most comprehensive light curves to date of a short-hard burst at such an early epoch. The afterglows exhibit complex structure with different decay indices and flaring. This behavior can be explained by the combination of a structured jet, radiative loss of energy, and decreasing microphysics parameters occurring in a circumburst medium with densities varying by a factor of approximately two on a length scale of 10 17 cm. These density variations are normally associated with the environment of a massive star and inhomogeneities in its windy medium. However, the mean density of the observed medium (n $ 10 À4 cm 3) is much less than that expected for a massive star. Although the collapse of a massive star as the origin of GRB 060313 is unlikely, the merger of a compact binary also poses problems for explaining the behavior of this burst. Two possible suggestions for explaining this scenario are that some short bursts may arise from a mechanism that does not invoke the conventional compact binary model, or that soft late-time central engine activity is producing UV/optical but no X-ray flaring.
Astronomische Gesellschaft Meeting Abstracts, 2000
Cultura organizacional y su importancia dentro de la formación en turismo 69 Cultura organizacion... more Cultura organizacional y su importancia dentro de la formación en turismo 69 Cultura organizacional y su importancia dentro de la formación en turismo Organizational culture and its importance within tourism Cultura organizacional e sua importância na formação em turismoçç
Il Nuovo Cimento B, 2006
Résumé/Abstract Swift unprecedented fast follow-up observations of gamma-ray bursts have allowed ... more Résumé/Abstract Swift unprecedented fast follow-up observations of gamma-ray bursts have allowed us to discover a new feature of GRB afterglows: a phase of shallow decay, usually attributed to energy injection in the burst ejecta, which can last for several thousands of ...
We focus on two systems. The first is the Be/X-ray binary Swift J1626.6-5156, discovered in outbu... more We focus on two systems. The first is the Be/X-ray binary Swift J1626.6-5156, discovered in outburst by the Swift Burst Alert Telescope (BAT) in December 2005. Monitoring by the Rossi X-ray Timing Explorer (RXTE) has revealed a 45-day quasi-period in its long-term light curve, one cycle of which was observed in near-simultaneity by the Swift UV/optical Telescope (UVOT) and X-Ray
The Astrophysical Journal, 2008
We present the first Swift Ultra-Violet/Optical Telescope (UVOT) gammaray burst (GRB) afterglow c... more We present the first Swift Ultra-Violet/Optical Telescope (UVOT) gammaray burst (GRB) afterglow catalog. The catalog contains data from over 64, 000 independent UVOT image observations of 229 GRBs first detected by Swift, the High Energy Transient Explorer 2 (HETE2), the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), and the Interplanetary Network (IPN). The catalog covers GRBs occurring during the period from 2005 Jan 17 to 2007 Jun 16 and includes ∼ 86% of the bursts detected by the Swift Burst Alert Telescope (BAT). The catalog provides detailed burst positional, temporal, and photometric information extracted from each of the UVOT images. Positions for bursts detected at the 3σ-level are provided with a nominal accuracy, relative to the USNO-B1 catalog, of ∼ 0. ′′ 25. Photometry for each burst is given in three UV bands, three optical bands, and a 'white' or open filter. Upper limits for magnitudes are reported for sources detected below 3σ. General properties of the burst sample and light curves, including the filter-dependent temporal slopes, are also provided. The majority of the UVOT light curves, for bursts detected at
The Astrophysical Journal, 1994
The Astrophysical Journal, 2006
We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray ba... more We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray bands by the Swift BAT and the Konus-Wind instruments of the short-hard burst, GRB 060313. The observations reveal multiple peaks in both the gamma-ray and hard X-ray bands suggesting a highly variable outflow from the central explosion. We also describe the early-time observations of the X-ray and UV/optical afterglows by the Swift XRT and UVOT instruments. The combination of the X-ray and UV/optical observations provides the most comprehensive light curves to date of a short-hard burst at such an early epoch. The afterglows exhibit complex structure with different decay indices and flaring. This behavior can be explained by the combination of a structured jet, radiative loss of energy, and decreasing microphysics parameters occurring in a circumburst medium with densities varying by a factor of approximately two on a length scale of 10 17 cm. These density variations are normally associated with the environment of a massive star and inhomogeneities in its windy medium. However, the mean density of the observed medium (n $ 10 À4 cm 3) is much less than that expected for a massive star. Although the collapse of a massive star as the origin of GRB 060313 is unlikely, the merger of a compact binary also poses problems for explaining the behavior of this burst. Two possible suggestions for explaining this scenario are that some short bursts may arise from a mechanism that does not invoke the conventional compact binary model, or that soft late-time central engine activity is producing UV/optical but no X-ray flaring.