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Catalogue XRT results for GRB 130427A

About these products.

Back to list of GRBs.

Non-standard pipeline processing was used to produce these data. The pointing accuracy requirements for the first snapshot has been removed, and the UVOT-derived attitude file used.

Summary Information

RA:11h 32m 32.36sLC breaks:5
Dec:+27° 41′ 54.8′′LC type:Canonical.
Err:3.5′′NH,intr.:8.79×1020 cm-2
Gal long:206.509Redshift0.34
Gal lat:72.500Γ1.7
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Jump to: Light curve | Spectra | Compare to other bursts.

If you use any of these data, please cite Evans et al. (2009), which describes how these products were created (see the usage policy for more information).

Light curve

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This light curve comes from the light curve repository (if you use it, please cite Evans et al [2007, 2009]. Flares, marked by cross-hatched regions, are identified automatically, but may have been manually corrected. These are excluded from the fit. Any power-law breaks added to the fit must be required at the 4-σ level (according to an f-test) to be included in the best-fit. Details of all fits attempted are given below the plot. For more information see the light curve fitting documentation.

Fitted light curve of GRB 130427A

Fit Details

Nbreaksχ2dofCommentsImage
040371659Image of this fit
122771657Break required.

(1.06e-204 % probability of chance improvement)
Image of this fit
222511655Break significance <4-σ
(7.13e-03 % probability of chance improvement)
Image of this fit
318631653Break required.

(1.73e-68 % probability of chance improvement)
Image of this fit
418351651Break required.

(2.52e-04 % probability of chance improvement)
Image of this fit
518001649Break required.

(1.61e-05 % probability of chance improvement).
This is the best fit.
Image of this fit

There are 1 flares excluded from the fit:

  • 219—272 s

The best-fitting light curve has 5 breaks.

Click on the number of breaks in the table to the right to change which fit is plotted above and detailed below.

Currently showing the best fit.

α11.71 (+0.34, -0.23)
Tb,1207 (+6, -7) s
α27.984 (+0.016, -2.217)
Tb,2226 (+25, -5) s
α32.428 (+0.156, -0.082)
Tb,3424 (+16, -16) s
α41.41 (+0.05, -0.05)
Tb,4889 (+42, -43) s
α50.95 (+0.03, -0.04)
Tb,51919 (+290, -161) s
α61.317 (+0.010, -0.006)

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Spectra

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Spectra have been created for each power-law segment in the best fitting light curve (shown above). Times of flaring have not been removed, however this makes little difference to most spectra (see Fig 7/8c of Evans et al. 2009). For more information see the time-resolved spectroscopy documentation.

Jump to: phase1|phase2|phase3|phase4|phase5|phase6

phase1 spectrum (T0 + 143 to 206 s)

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Plots to download

WT mode spectrum of GRB 130427A

WT mode. Mean photon arrival: T0+170 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)2.1 (+0.5, -0.4) × 1021 cm-2
z of absorber0.34
Photon index1.96 (+0.11, -0.10)
Flux (0.3-10 keV)
(Observed)
2.14 (+0.14, -0.13) × 10-7 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
2.85 (+0.16, -0.15) × 10-7 erg cm-2 s-1
Counts to flux (obs)3.53 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.69 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
495.01 (510)
Spectrum exposure62 s

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phase2 spectrum (T0 + 206 to 225 s)

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WT mode spectrum of GRB 130427A

WT mode. Mean photon arrival: T0+215 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)1.2 (+0.6, -0.5) × 1021 cm-2
z of absorber0.34
Photon index2.06 (+0.17, -0.16)
Flux (0.3-10 keV)
(Observed)
1.29 (+0.12, -0.11) × 10-7 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.63 (+0.15, -0.13) × 10-7 erg cm-2 s-1
Counts to flux (obs)3.23 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.08 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
297.86 (336)
Spectrum exposure19 s

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phase3 spectrum (T0 + 225 to 423 s)

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WT mode spectrum of GRB 130427A

WT mode. Mean photon arrival: T0+325 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)0 (+3.47 × 1019, -0) cm-2
z of absorber0.34
Photon index1.750 (+0.041, -0.020)
Flux (0.3-10 keV)
(Observed)
4.47 (+0.10, -0.11) × 10-8 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
4.68 (+0.11, -0.10) × 10-8 erg cm-2 s-1
Counts to flux (obs)3.62 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.79 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
880.49 (699)
Spectrum exposure197 s

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phase4 spectrum (T0 + 423 to 889 s)

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Plots to download

WT mode spectrum of GRB 130427A

WT mode. Mean photon arrival: T0+644 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)1.6 (+10.8, -1.6) × 1019 cm-2
z of absorber0.34
Photon index1.476 (+0.028, -0.020)
Flux (0.3-10 keV)
(Observed)
1.83 (+0.03, -0.03) × 10-8 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.88 (+0.03, -0.03) × 10-8 erg cm-2 s-1
Counts to flux (obs)4.31 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.45 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
1021.15 (806)
Spectrum exposure465 s

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phase5 spectrum (T0 + 889 to 1918 s)

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WT mode spectrum of GRB 130427A

WT mode. Mean photon arrival: T0+1371 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)4.9 (+0.8, -0.8) × 1020 cm-2
z of absorber0.34
Photon index1.562 (+0.020, -0.020)
Flux (0.3-10 keV)
(Observed)
7.61 (+0.10, -0.10) × 10-9 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
8.19 (+0.09, -0.09) × 10-9 erg cm-2 s-1
Counts to flux (obs)4.21 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.53 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
1116.57 (848)
Spectrum exposure1.0 ks

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phase6 spectrum (T0 + 1918 to 15781071 s)

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WT and PC mode spectra of GRB 130427A

WT mode. Mean photon arrival: T0+5574 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)9 (+3, -3) × 1020 cm-2
z of absorber0.34
Photon index1.74 (+0.08, -0.08)
Flux (0.3-10 keV)
(Observed)
1.35 (+0.07, -0.07) × 10-9 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.54 (+0.06, -0.06) × 10-9 erg cm-2 s-1
Counts to flux (obs)3.77 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.30 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
470.80 (533)
Spectrum exposure141 s

PC mode. Mean photon arrival: T0+712132 s

NH (Galactic)1.91 × 1020 cm-2
NH (intrinsic)9.4 (+1.4, -1.4) × 1020 cm-2
z of absorber0.34
Photon index1.74 (+0.04, -0.04)
Flux (0.3-10 keV)
(Observed)
1.40 (+0.03, -0.03) × 10-12 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.60 (+0.03, -0.03) × 10-12 erg cm-2 s-1
Counts to flux (obs)3.86 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.42 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
700.86 (755)
Spectrum exposure453.8 ks

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Comparison with other bursts

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Parameter distributions

The plots below show the probability density functions of the temporal and time-averaged spectral parameters for all GRBs, with the data for GRB 130427A shown on in colour. Click the images for larger versions.

For all plots, the solid vertical lines mark the values for this GRB, and the dashed lines the 1-σ uncertainties. For α and Tb, the colour changes for each phase. For the spectral parameters, the WT fits are shown in blue and the PC in red. These figures correspond to Figs. 5,6, 7a and 8a of Evans et al. (2009). See the PDF documentation for more information.

Temporal indicesBreak TimesNHSpectral indices
Comparison of decay indices Comparison of light curve break times Comparison of intrinsic column densities Comparison of spectral energy indices

Closure Relationships

The plots below show (α, β) scatter plots for each phase of all Canonical light curves. GRB 130427A is shown in colour; where multiple points appear in a given phase (e.g. WT and PC mode spectra for that phase), the different colours refer to different spectra. α and β are the temporal and spectral energy power-law indices respectively. The shaded regions mark those allowed by the standard closure relationships. These figures correspond to Fig. 10 of Evans et al. (2009). See the closure relationship documentation for more information.

Canonical
Steep phase
Canonical
Plateau
Canonical
'Normal'
Canonical
Post jet-break
Comparison of Canonical, steep phase closuresComparison of Canonical, plateau phase closuresComparison of Canonical, normal phase closuresComparison of Canonical, post jet-break phase closures

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