A study of gamma-ray burst afterglows as they first come into view of the swift ultraviolet and optical telescope

M. J. Page, S. R. Oates, M. de Pasquale, A. A. Breeveld, S. W.K. Emery, N. P.M. Kuin, F. E. Marshall, M. H. Siegel, P. W.A. Roming

Research output: Contribution to journalArticle

Abstract

We examine the emission from optically bright gamma-ray burst (GRB) afterglows, as the Ultraviolet and Optical Telescope (UVOT) on the Neil Gehrels Swift Observatory first begins observing, following the slew to target the GRB, while the pointing of the Swift satellite is still settling. We verify the photometric quality of the UVOT settling data using bright stars in the field of view. In the majority of cases, we find no problems with the settling exposure photometry, but in one case, we excise the first second of the exposure to mitigate a spacecraft attitude reconstruction issue, and in a second case, we exclude the first second of the exposure in which the UVOT photocathode voltage appears to be ramping up. Of a sample of 23 afterglows which have peak V magnitudes <16, we find that all are detected in the settling exposures, when Swift arrives on target. For nine of the GRBs, the UVOT settling exposure took place before the conclusion of the prompt gamma-ray emission. Five of these GRBs have well-defined optical peaks after the settling exposures, with rises of >0.5 mag in their optical light curves, and there is a marginal trend for these GRBs to have long T90. Such a trend is expected for thick-shell afterglows, but the temporal indices of the optical rises and the timing of the optical peaks appear to rule out thick shells.

Original languageEnglish (US)
Pages (from-to)2855-2863
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Volume488
Issue number2
DOIs
StatePublished - Jan 1 2019

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ultraviolet telescopes
settling
afterglows
gamma ray bursts
telescopes
Swift observatory
shell
trends
photocathodes
field of view
light curve
photometry
spacecraft
observatory
time measurement
stars
electric potential
exposure
trend

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Page, M. J., Oates, S. R., de Pasquale, M., Breeveld, A. A., Emery, S. W. K., Kuin, N. P. M., ... Roming, P. W. A. (2019). A study of gamma-ray burst afterglows as they first come into view of the swift ultraviolet and optical telescope. Monthly Notices of the Royal Astronomical Society, 488(2), 2855-2863. https://doi.org/10.1093/mnras/stz1845
Page, M. J. ; Oates, S. R. ; de Pasquale, M. ; Breeveld, A. A. ; Emery, S. W.K. ; Kuin, N. P.M. ; Marshall, F. E. ; Siegel, M. H. ; Roming, P. W.A. / A study of gamma-ray burst afterglows as they first come into view of the swift ultraviolet and optical telescope. In: Monthly Notices of the Royal Astronomical Society. 2019 ; Vol. 488, No. 2. pp. 2855-2863.
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Page, MJ, Oates, SR, de Pasquale, M, Breeveld, AA, Emery, SWK, Kuin, NPM, Marshall, FE, Siegel, MH & Roming, PWA 2019, 'A study of gamma-ray burst afterglows as they first come into view of the swift ultraviolet and optical telescope', Monthly Notices of the Royal Astronomical Society, vol. 488, no. 2, pp. 2855-2863. https://doi.org/10.1093/mnras/stz1845

A study of gamma-ray burst afterglows as they first come into view of the swift ultraviolet and optical telescope. / Page, M. J.; Oates, S. R.; de Pasquale, M.; Breeveld, A. A.; Emery, S. W.K.; Kuin, N. P.M.; Marshall, F. E.; Siegel, M. H.; Roming, P. W.A.

In: Monthly Notices of the Royal Astronomical Society, Vol. 488, No. 2, 01.01.2019, p. 2855-2863.

Research output: Contribution to journalArticle

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AU - Page, M. J.

AU - Oates, S. R.

AU - de Pasquale, M.

AU - Breeveld, A. A.

AU - Emery, S. W.K.

AU - Kuin, N. P.M.

AU - Marshall, F. E.

AU - Siegel, M. H.

AU - Roming, P. W.A.

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