Abstract
GRB 050223 was discovered by the Swift Gamma-Ray Burst Explorer on 2005 February 23 and was the first gamma-ray burst (GRB) to be observed by both Swift and XMM-Newton. At the time of writing (2005 May), it has one of the faintest GRB afterglows ever observed. The spacecraft could not slew immediately to the burst, so the first X-ray and optical observations occurred approximately 45 min after the trigger. Although no optical emission was found by any instrument, both Swift and XMM-Newton detected the fading X-ray afterglow. Combined data from both of these observatories show the afterglow to be fading monotonically as 0.99+0.15 -0.12 over a time-frame between 45 min and 27 h post-burst. Spectral analysis, allowed largely by the higher throughput of XMM-Newton, implies a power law with a slope of Γ = 1.75+0.19 -0.18and shows no evidence for absorption above the Galactic column of 7 × 1020 cm-2. From the X-ray decay and spectral slopes, a low electron power-law index of p = 1.3-1.9 is derived; the slopes also imply that a jet-break has not occurred up to 27 h after the burst. The faintness of GRB 050223 may be due to a large jet opening or viewing angle or a high redshift.
| Original language | English (US) |
|---|---|
| Journal | Monthly Notices of the Royal Astronomical Society: Letters |
| Volume | 363 |
| Issue number | 1 |
| DOIs | |
| State | Published - Oct 1 2005 |
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All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
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GRB 050223 : A faint gamma-ray burst discovered by Swift. / Page, K. L.; Rol, E.; Levan, A. J.; Zhang, B.; Osborne, J. P.; O'Brien, P. T.; Beardmore, A. P.; Burrows, David Nelson; Campana, S.; Chincharini, G.; Cummings, J. R.; Cusumano, G.; Gehrels, N.; Giommi, P.; Goad, M. R.; Godet, O.; Mangano, V.; Tagliaferri, G.; Wells, A. A.
In: Monthly Notices of the Royal Astronomical Society: Letters, Vol. 363, No. 1, 01.10.2005.Research output: Contribution to journal › Letter
TY - JOUR
T1 - GRB 050223
T2 - A faint gamma-ray burst discovered by Swift
AU - Page, K. L.
AU - Rol, E.
AU - Levan, A. J.
AU - Zhang, B.
AU - Osborne, J. P.
AU - O'Brien, P. T.
AU - Beardmore, A. P.
AU - Burrows, David Nelson
AU - Campana, S.
AU - Chincharini, G.
AU - Cummings, J. R.
AU - Cusumano, G.
AU - Gehrels, N.
AU - Giommi, P.
AU - Goad, M. R.
AU - Godet, O.
AU - Mangano, V.
AU - Tagliaferri, G.
AU - Wells, A. A.
PY - 2005/10/1
Y1 - 2005/10/1
N2 - GRB 050223 was discovered by the Swift Gamma-Ray Burst Explorer on 2005 February 23 and was the first gamma-ray burst (GRB) to be observed by both Swift and XMM-Newton. At the time of writing (2005 May), it has one of the faintest GRB afterglows ever observed. The spacecraft could not slew immediately to the burst, so the first X-ray and optical observations occurred approximately 45 min after the trigger. Although no optical emission was found by any instrument, both Swift and XMM-Newton detected the fading X-ray afterglow. Combined data from both of these observatories show the afterglow to be fading monotonically as 0.99+0.15 -0.12 over a time-frame between 45 min and 27 h post-burst. Spectral analysis, allowed largely by the higher throughput of XMM-Newton, implies a power law with a slope of Γ = 1.75+0.19 -0.18and shows no evidence for absorption above the Galactic column of 7 × 1020 cm-2. From the X-ray decay and spectral slopes, a low electron power-law index of p = 1.3-1.9 is derived; the slopes also imply that a jet-break has not occurred up to 27 h after the burst. The faintness of GRB 050223 may be due to a large jet opening or viewing angle or a high redshift.
AB - GRB 050223 was discovered by the Swift Gamma-Ray Burst Explorer on 2005 February 23 and was the first gamma-ray burst (GRB) to be observed by both Swift and XMM-Newton. At the time of writing (2005 May), it has one of the faintest GRB afterglows ever observed. The spacecraft could not slew immediately to the burst, so the first X-ray and optical observations occurred approximately 45 min after the trigger. Although no optical emission was found by any instrument, both Swift and XMM-Newton detected the fading X-ray afterglow. Combined data from both of these observatories show the afterglow to be fading monotonically as 0.99+0.15 -0.12 over a time-frame between 45 min and 27 h post-burst. Spectral analysis, allowed largely by the higher throughput of XMM-Newton, implies a power law with a slope of Γ = 1.75+0.19 -0.18and shows no evidence for absorption above the Galactic column of 7 × 1020 cm-2. From the X-ray decay and spectral slopes, a low electron power-law index of p = 1.3-1.9 is derived; the slopes also imply that a jet-break has not occurred up to 27 h after the burst. The faintness of GRB 050223 may be due to a large jet opening or viewing angle or a high redshift.
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U2 - 10.1111/j.1745-3933.2005.00086.x
DO - 10.1111/j.1745-3933.2005.00086.x
M3 - Letter
VL - 363
JO - Monthly Notices of the Royal Astronomical Society: Letters
JF - Monthly Notices of the Royal Astronomical Society: Letters
SN - 1745-3925
IS - 1
ER -