Skip banner and navigation tools.

 |  site map

Catalogue XRT results for GRB 151228B

Data were analysed using HEASOFT version 6.29

About these products.

Back to list of GRBs.

Summary Information

RA:22h 57m 41.89sLC breaks:3
Dec:+08° 04′ 52.9′′LC type:Canonical.
Err:1.6′′NH,intr.:8.48×1012 cm-2
Gal long:80.852RedshiftUnknown
Gal lat:-45.296Γ1.9
| |

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

Hide the light curve section.

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 151228B

Fit Details

Nbreaksχ2dofCommentsImage
047376Image of this fit
128274Break required.

(5.48e-07 % probability of chance improvement)
Image of this fit
211172Break required.

(2.61e-13 % probability of chance improvement)
Image of this fit
366.970Break required.

(1.79e-06 % probability of chance improvement).
This is the best fit.
Image of this fit
464.968Break significance <4-σ
(37.03 % probability of chance improvement)
Image of this fit
563.866Break significance <4-σ
(53.32 % probability of chance improvement)
Image of this fit

There are 1 flares excluded from the fit:

  • 103—281 s

The best-fitting light curve has 3 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.

α11.63 (+0.13, -0.13)
Tb,1139 (+80, -51) s
α23.70 (+2.02, -0.64)
Tb,2526 (+100, -93) s
α30.63 (+0.07, -0.08)
Tb,31.20 (+0.71, -1.07) × 105 s
α44 (+4, -3)

[Back to top]


Spectra

Hide the spectrum section.

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

phase1 spectrum (T0 + 55 to 139 s)

Download spectral files for phase1 spectrum.

Plots to download

WT mode spectrum of GRB 151228B

WT mode. Mean photon arrival: T0+90 s

NH (Galactic)5.75 × 1020 cm-2
NH (intrinsic)1.84 (+0.26, -0.25) × 1021 cm-2
z of absorber0
Photon index2.43 (+0.09, -0.08)
Flux (0.3-10 keV)
(Observed)
2.45 (+0.10, -0.09) × 10-9 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
4.34 (+0.17, -0.22) × 10-9 erg cm-2 s-1
Counts to flux (obs)2.87 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)5.10 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
464.39 (490)
Spectrum exposure83 s

[Back to top]


phase2 spectrum (T0 + 139 to 526 s)

Download spectral files for phase2 spectrum.

Plots to download

WT and PC mode spectra of GRB 151228B

WT mode. Mean photon arrival: T0+172 s

NH (Galactic)5.75 × 1020 cm-2
NH (intrinsic)1.0 (+0.5, -0.4) × 1021 cm-2
z of absorber0
Photon index3.31 (+0.33, -0.25)
Flux (0.3-10 keV)
(Observed)
3.15 (+0.24, -0.24) × 10-10 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
7.9 (+2.7, -3.6) × 10-10 erg cm-2 s-1
Counts to flux (obs)2.20 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)5.51 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
274.51 (223)
Spectrum exposure110 s

PC mode. Mean photon arrival: T0+345 s

NH (Galactic)5.75 × 1020 cm-2
NH (intrinsic)0 (+1.80 × 1020, -0) cm-2
z of absorber0
Photon index2.29 (+0.38, -0.25)
Flux (0.3-10 keV)
(Observed)
3.1 (+0.7, -0.6) × 10-11 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
3.14 (+1.10, -0.31) × 10-11 erg cm-2 s-1
Counts to flux (obs)2.85 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)2.92 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
67.81 (60)
Spectrum exposure275 s

[Back to top]


phase3 spectrum (T0 + 527 to 120210 s)

Download spectral files for phase3 spectrum.

Plots to download

PC mode spectrum of GRB 151228B

PC mode. Mean photon arrival: T0+9371 s

NH (Galactic)5.75 × 1020 cm-2
NH (intrinsic)2.5 (+6.8, -2.5) × 1020 cm-2
z of absorber0
Photon index1.95 (+0.26, -0.21)
Flux (0.3-10 keV)
(Observed)
1.65 (+0.26, -0.22) × 10-12 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.94 (+0.25, -0.22) × 10-12 erg cm-2 s-1
Counts to flux (obs)3.38 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.00 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
150.40 (189)
Spectrum exposure9.9 ks

[Back to top]


phase4 spectrum (T0 + 126043 to 545907 s)

Download spectral files for phase4 spectrum.

Plots to download

PC mode spectrum of GRB 151228B

PC mode. Mean photon arrival: T0+275456 s

NH (Galactic)5.75 × 1020 cm-2
NH (intrinsic)0 (+1.81 × 1022, -0) cm-2
z of absorber0
Photon index1.7 (+3.3, -2.1)
Flux (0.3-10 keV)
(Observed)
2.1 (+2.5, -1.5) × 10-14 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
2.4 (+2.6, -1.7) × 10-14 erg cm-2 s-1
Counts to flux (obs)3.69 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.26 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
5.93 (5)
Spectrum exposure16.9 ks

[Back to top]



Comparison with other bursts

Hide the comparison section.

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 151228B 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 151228B 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

[Back to top]