Francisco J Virgili Prompt GRB Conference, 2011 March 5, 2011; Raleigh, NC.
Prompt optical observations of GRB 080330 and GRB 080413A.
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Transcript of Prompt optical observations of GRB 080330 and GRB 080413A.
Prompt optical observations of GRB 080330 and GRB 080413A
Background & Motivation
• Growing number of early optical afterglow observations– Collective study of temporal behavior– Panaitescu & Vestrand 2008: peak time and peak flux
correlation
• Growing number of prompt optical observations– Some show complicated behavior, GRB 08330 and GRB
080413a– Multiple components from both internal and external
shock?– Start from the better-understood afterglow part
2008 Mar. 30, 03:41:39.2
22.4 s after the burst (7.2 s after the GCN notice time)
Schaefer & Guver, GCN 7538
2008 Apr. 13, 02:54:39.7
20.4 s after the burst (6.7 s after the GCN notice time)
Rykoff & Rujopakarn, GCN 7593
2008 Mar. 30, 03:41:39.2
22.4 s after the burst (7.2 s after the GCN notice time)
Schaefer & Guver, GCN 7538
2008 Apr. 13, 02:54:39.7
20.4 s after the burst (6.7 s after the GCN notice time)
Rykoff & Rujopakarn, GCN 7593
2008 Mar. 30, 03:41:39.2
22.4 s after the burst (7.2 s after the GCN notice time)
Schaefer & Guver, GCN 7538
2008 Apr. 13, 02:54:39.7
20.4 s after the burst (6.7 s after the GCN notice time)
Rykoff & Rujopakarn, GCN 7593
GRB 080330
GRB 080330
GRB 080413a
GRB 080413a
Slowly decaying afterglow
• Structured flow viewed off-axis?
• Drowned by prompt emission in X-ray?
Panaitescu & Vestrand 2008
• Eγ,iso = 5.0 x 1051 erg
• γ = 2.5 +/-0.5
• tpeak ~ 150 s
• Γ0 ~ 200
(Sari & Piran 1999, Molinari et al. 2007)
• Can be classified as XRF(Sakamoto et al. 2008, Mao et al. 2008)
• Eγ,iso = 1.7 x 1053 erg• γ = 1.5 +/-0.1
• tpeak ~ 30 s• Γ0 ~ 600
Rising of afterglow
‘Prompt’ optical flash
Other ROTSE-III events
• Eγ,iso = 3.1 x 1051 erg• γ = 1.9 +/-0.1
• tpeak ~ 200 s• Γ0 ~ 150
• Eγ,iso = 4.2 x 1053 erg• γ = 1.1 +/-0.0
• tpeak ~ 40 s• Γ0 ~ 600
Rykoff 2008 in preparation
Summary
• ‘Prompt’ optical component – Need better sampling– Complicated by early afterglow– Better understanding of the afterglow phase will help
• Low Lorentz factor events– Delayed afterglow peak– Easier to observe the peak and shape of the early lightcurve
Next with ROTSE-III
• More interesting events from Swift (sub-threshold triggers)
• GLAST launched• ROTSE supernova verification project• Follow-up of IceCube neutrino doublet triggers
Thank you!
2.5 2.1 1.5 2.0 2.1
1.9
3.11.5