All Figures

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig1.eps} \end{figure}$ Figure 1: The X-ray lightcurve obtained by Swift/XRT starting 7.1 h after the event onset and continuing up to 10 days later. The data are fit by a power-law decline exponent $\alpha _{\rm X} = -1.1_{-0.2}^{+0.1}$ .
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In the text

$\begin{figure} \par\psfrag{nh}[t][r]{\LARGE nH = 10$^{22}$\space cm$^{-2}$ } \p... ...m$^2$ } \resizebox{8.5cm}{!}{\includegraphics{4757fig2.eps}} \par\end{figure}$ Figure 2: The X-ray spectrum obtained by Swift/XRT for the time interval T₀ + 7.1 h to T₀ + 13.2 h. The data can be fitted by a power-law with photon index $\Gamma = 2.3_{-0.25}^{+0.30}$ .
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In the text

$\begin{figure} \par\psfrag{NH}[l]{\LARGE$N_{H, GAL} \sim$\space 1.2$\times$ 10$^... ...} \resizebox{8.5cm}{!}{\includegraphics[clip]{4757fig3.eps}} \par\end{figure}$ Figure 3: Contour plot of column density versus photon index for the absorbed power law model shown in Fig. 2. The dashed line shows the estimated Galactic column density value $1.2 \times 10^{21}$ cm^-2 and the contours denote 68%, 90% and 99% confidence levels respectively. The spectrum is compatible (90% confidence) with Galactic absorption.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig4.eps} \end{figure}$ Figure 4: The deep R band image of the GRB 051028 field taken at the 4.2WHT on 28 Oct. 2005. The optical afterglow within the 3 $.\!\!^{\prime\prime}$ 8 Swift/XRT error box (circle) is depicted. The field is $2\hbox {$.\mkern -4mu^\prime $ }5 \times 1\hbox {$.\mkern -4mu^\prime $ }9$ with North up and East to the left.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig5.eps} \end{figure}$ Figure 5: The R and I-band lightcurves (including the V-band single detection) obtained at Hanle (HCT), Tautenburg and La Palma (WHT) starting 2.7 h after the event onset and continuing up to 3.5 days later. The data after 4.0 h are fit by a power-law decline exponent $\alpha _{\rm opt} = -0.9 \pm 0.1$ .
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig6.eps} \end{figure}$ Figure 6: The GRB 051028 R and I-band light curves shifted by $\sim$ 3 mag in order to match the GRB 050730 R-band lightcurve (from Pandey et al. 2006). No shift in the T-T₀ values has been performed. These combined data strengthen the evidence of a "bumpy'' behaviour of the GRB 051028 afterglow.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig7.eps} \end{figure}$ Figure 7: The $\beta _{\rm opt}$ spectral indexes obtained for GRB optical afterglows in the redshift range 3 < z < 4.5 based solely on the $\it VRI$ data. The $\beta _{\rm opt}$ value derived for GRB 051028 is in the range of those derived for this high-z sample and therefore supports that GRB 051028 also arose at a z = 3-4.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig1.eps} \end{figure}$	Figure 1: The X-ray lightcurve obtained by Swift/XRT starting 7.1 h after the event onset and continuing up to 10 days later. The data are fit by a power-law decline exponent $\alpha _{\rm X} = -1.1_{-0.2}^{+0.1}$ .
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$\begin{figure} \par\psfrag{nh}[t][r]{\LARGE nH = 10$^{22}$\space cm$^{-2}$ } \p... ...m$^2$ } \resizebox{8.5cm}{!}{\includegraphics{4757fig2.eps}} \par\end{figure}$	Figure 2: The X-ray spectrum obtained by Swift/XRT for the time interval T₀ + 7.1 h to T₀ + 13.2 h. The data can be fitted by a power-law with photon index $\Gamma = 2.3_{-0.25}^{+0.30}$ .
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$\begin{figure} \par\psfrag{NH}[l]{\LARGE$N_{H, GAL} \sim$\space 1.2$\times$ 10$^... ...} \resizebox{8.5cm}{!}{\includegraphics[clip]{4757fig3.eps}} \par\end{figure}$	Figure 3: Contour plot of column density versus photon index for the absorbed power law model shown in Fig. 2. The dashed line shows the estimated Galactic column density value $1.2 \times 10^{21}$ cm^-2 and the contours denote 68%, 90% and 99% confidence levels respectively. The spectrum is compatible (90% confidence) with Galactic absorption.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig4.eps} \end{figure}$	Figure 4: The deep R band image of the GRB 051028 field taken at the 4.2WHT on 28 Oct. 2005. The optical afterglow within the 3 $.\!\!^{\prime\prime}$ 8 Swift/XRT error box (circle) is depicted. The field is $2\hbox {$.\mkern -4mu^\prime $ }5 \times 1\hbox {$.\mkern -4mu^\prime $ }9$ with North up and East to the left.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig5.eps} \end{figure}$	Figure 5: The R and I-band lightcurves (including the V-band single detection) obtained at Hanle (HCT), Tautenburg and La Palma (WHT) starting 2.7 h after the event onset and continuing up to 3.5 days later. The data after 4.0 h are fit by a power-law decline exponent $\alpha _{\rm opt} = -0.9 \pm 0.1$ .
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$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig6.eps} \end{figure}$	Figure 6: The GRB 051028 R and I-band light curves shifted by $\sim$ 3 mag in order to match the GRB 050730 R-band lightcurve (from Pandey et al. 2006). No shift in the T-T₀ values has been performed. These combined data strengthen the evidence of a "bumpy'' behaviour of the GRB 051028 afterglow.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8cm,clip]{4757fig7.eps} \end{figure}$	Figure 7: The $\beta _{\rm opt}$ spectral indexes obtained for GRB optical afterglows in the redshift range 3 < z < 4.5 based solely on the $\it VRI$ data. The $\beta _{\rm opt}$ value derived for GRB 051028 is in the range of those derived for this high-z sample and therefore supports that GRB 051028 also arose at a z = 3-4.
Open with DEXTER