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Catalogue XRT results for GRB 070518

Data were analysed using HEASOFT version 6.29

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Summary Information

RA:16h 56m 47.66sLC breaks:1
Dec:+55° 17′ 41.4′′LC type:One-break, steep first.
Err:1.8′′NH,intr.:1.26×1020 cm-2
Gal long:83.482RedshiftUnknown
Gal lat:38.162Γ2.1
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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 070518

Fit Details

Nbreaksχ2dofCommentsImage
024620Image of this fit
128.718Break required.

(4.01e-07 % probability of chance improvement).
This is the best fit.
Image of this fit
222.016Break significance <4-σ
(11.91 % probability of chance improvement)
Image of this fit
316.714Break significance <4-σ
(8.95 % probability of chance improvement)
Image of this fit

There are 1 flares excluded from the fit:

  • 98.5—291 s

The best-fitting light curve has 1 break.

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.

α12.21 (+0.18, -0.12)
Tb,1948 (+259, -270) s
α20.73 (+0.06, -0.06)

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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

phase1 spectrum (T0 + 76 to 948 s)

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Plots to download

WT and PC mode spectra of GRB 070518

WT mode. Mean photon arrival: T0+153 s

NH (Galactic)1.57 × 1020 cm-2
NH (intrinsic)7.0 (+2.0, -1.9) × 1020 cm-2
z of absorber0
Photon index2.489 (+0.104, -0.100)
Flux (0.3-10 keV)
(Observed)
4.51 (+0.21, -0.20) × 10-10 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
6.26 (+0.28, -0.37) × 10-10 erg cm-2 s-1
Counts to flux (obs)2.63 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.65 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
361.69 (395)
Spectrum exposure178 s

PC mode. Mean photon arrival: T0+510 s

NH (Galactic)1.57 × 1020 cm-2
NH (intrinsic)5 (+88, -5) × 1019 cm-2
z of absorber0
Photon index2.05 (+0.45, -0.27)
Flux (0.3-10 keV)
(Observed)
8.4 (+1.9, -1.8) × 10-12 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
8.9 (+2.0, -1.8) × 10-12 erg cm-2 s-1
Counts to flux (obs)3.13 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.33 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
49.67 (70)
Spectrum exposure694 s

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phase2 spectrum (T0 + 950 to 1672774 s)

Download spectral files for phase2 spectrum.

Plots to download

PC mode spectrum of GRB 070518

PC mode. Mean photon arrival: T0+246190 s

NH (Galactic)1.57 × 1020 cm-2
NH (intrinsic)8.8 (+11.6, -8.2) × 1020 cm-2
z of absorber0
Photon index2.3 (+0.5, -0.4)
Flux (0.3-10 keV)
(Observed)
4.3 (+1.0, -0.8) × 10-14 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
5.88 (+1.12, -0.86) × 10-14 erg cm-2 s-1
Counts to flux (obs)2.86 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.88 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
119.42 (153)
Spectrum exposure179.7 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 070518 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 One-break, steep first light curves. GRB 070518 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.

One-break, steep first
Steep phase
One-break, steep first
Shallow phase
Comparison of One-break, steep first, steep phase closuresComparison of One-break, steep first, shallow phase closures

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