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Catalogue XRT results for GRB 170318B

Data were analysed using HEASOFT version 6.32

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Summary Information

RA:18h 57m 13.45sLC breaks:0
Dec:+06° 17′ 57.1′′LC type:No breaks.
Err:1.7′′NH,intr.:5.39×1022 cm-2
Gal long:39.197RedshiftUnknown
Gal lat:1.587Γ2.3
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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 170318B

Fit Details

Nbreaksχ2dofCommentsImage
042.38Image of this fit
117.96Break significance <4-σ
(7.58 % probability of chance improvement)
Image of this fit
25.34Break significance <4-σ
(4.29 % probability of chance improvement)
Image of this fit

There are 1 flares excluded from the fit:

  • 111—298 s

The best-fitting light curve has 0 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.

α11.74 (+0.13, -0.11)

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Spectra

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Since there are no breaks in the light curve, only the time-averaged spectra are shown below. 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.

Time-averaged spectrum (T0 + 80 to 41116 s)

Download spectral files for Time-averaged spectrum.

Plots to download

WT and PC mode spectra of GRB 170318B

WT mode. Mean photon arrival: T0+125 s

NH (Galactic)1.35 × 1022 cm-2
NH (intrinsic)5.4 (+1.9, -1.6) × 1022 cm-2
z of absorber0
Photon index1.6 (+0.4, -0.4)
Flux (0.3-10 keV)
(Observed)
6.7 (+0.8, -0.8) × 10-10 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.5 (+0.8, -0.3) × 10-9 erg cm-2 s-1
Counts to flux (obs)9.56 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)2.08 × 10-10 erg cm-2 ct-1
W-stat (dof)
What's this?
293.48 (357)
Spectrum exposure95 s

PC mode. Mean photon arrival: T0+1308 s

NH (Galactic)1.35 × 1022 cm-2
NH (intrinsic)5.4 (+2.7, -2.2) × 1022 cm-2
z of absorber0
Photon index2.3 (+0.8, -0.7)
Flux (0.3-10 keV)
(Observed)
5.01 (+1.12, -0.88) × 10-12 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
2.3 (+5.6, -1.0) × 10-11 erg cm-2 s-1
Counts to flux (obs)8.24 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.74 × 10-10 erg cm-2 ct-1
W-stat (dof)
What's this?
115.78 (139)
Spectrum exposure7.1 ks


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 170318B 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 No breaks light curves. GRB 170318B 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.

No break
Comparison of nobreak closures

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