J/ApJ/672/449 GRB 061126 light curves (Perley+, 2008)
The troublesome broadband evolution of GRB 061126:
does a gray burst imply gray dust?
Perley D.A., Bloom J.S., Butler N.R., Pollack L.K., Holtzman J.,
Blake C.H., Kocevski D., Vestrand W.T., Li W., Foley R.J., Bellm E.,
Chen H.-W., Prochaska J.X., Starr D., Filippenko A.V., Falco E.E.,
Szentgyorgyi A.H., Wren J., Wozniak P.R., White R., Pergande J.
<Astrophys. J., 672, 449-464 (2008)>
=2008ApJ...672..449P 2008ApJ...672..449P
ADC_Keywords: Gamma rays ; Photometry
Keywords: gamma-rays: bursts
Abstract:
We report on observations of a gamma-ray burst (GRB 061126) with an
extremely bright (R∼12mag at peak) early-time optical afterglow. The
optical afterglow is already fading as a power law 22s after the
trigger, with no detectable prompt contribution in our first exposure,
which was coincident with a large prompt-emission gamma-ray pulse. The
optical-infrared photometric SED is an excellent fit to a power law,
but it exhibits a moderate red-to-blue evolution in the spectral index
at about 500s after the burst. This color change is contemporaneous
with a switch from a relatively fast decay to slower decay.
Description:
At 08:47:56 on 2006 November 26 (UT dates are used throughout this
paper), the Swift Burst Alert Telescope (BAT) triggered and located
GRB 061126. Unfortunately, due to an Earth limb constraint, Swift was
unable to slew promptly to the target for 23 minutes and could not
begin observations with the XRT or the Ultraviolet/Optical Telescope
(UVOT) before that time. After 23 minutes, Swift slewed to the burst
position and detected a fading X-ray afterglow (Sbarufatti et al.
2006GCN..5855....1S 2006GCN..5855....1S).
We download the Swift BAT and XRT data from the Swift Archive.
The XRT data are processed with version 0.10.3 of the xrtpipeline
reduction script from the HEAsoft 6.0.69 software release. We employ
the latest (2006 December 19) XRT and BAT calibration files.
Objects:
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RA (2000) DE Designation(s)
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05 46 24.5 +64 12 38 GRB 061126 = GRB 061126
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 412 XRT light curve of GRB
table2.dat 50 33 RAPTOR observations of GRB 061126
table3.dat 50 102 PAIRITEL observations of GRB 061126
table4.dat 50 50 NMSU 1m Observations of GRB 061126
table5.dat 50 27 KAIT and Lick 1m Observations of GRB 061126
table6.dat 50 30 UVOT Observations of GRB 061126
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.2 s Tstart Observation start time (1)
11- 20 F10.2 s Tend Observation end time (1)
22- 32 F11.8 uJy Flux Swift/XRT flux (2)
34- 44 F11.8 uJy e_Flux Uncertainty in Flux
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Note (1): Measured from the Swift trigger 26 November 2006 08:47:56.4 UT.
Note (2): Normalized to 1keV and corrected for NH absorption. The
conversion factor is 7.5µJy/cps.
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Byte-by-byte Description of file: table[23456].dat
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Bytes Format Units Label Explanations
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1- 7 F7.1 s Tmid Mid-time of exposure (1)
9- 13 A5 --- Filt Filter used (2)
15- 20 F6.1 s ExpTime Exposure time
22- 23 A2 --- l_mag [≥ ] Limit flag on mag
24- 28 F5.2 mag mag Observed magnitude in Filt (3)
30- 33 F4.2 mag e_mag ? Uncertainty in mag
34 A1 --- f_mag [c] Flag on mag (4)
35- 36 A2 --- l_Flux [≤ ] Limit flag on Flux
37- 43 F7.1 uJy Flux Observed flux (3)
45- 50 F6.1 uJy e_Flux ? Uncertainty in Flux
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Note (1): Measured from the Swift trigger 26 November 2006 08:47:56.4 UT.
Note (2): Filters used:
table2 : clear
table3 : J, H, Ks
table4 : U, B, V, R, I
table5 : V, R, I, clear
table6 : U, B, V, UVW1 (260nm), UVM2 (225nm), White
Note (3): Not corrected for Galactic extinction.
Note (4): c: Contemporaneous with strong GRB pulse; point not used in modeling.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 05-Apr-2010