Astronomy & Astrophysics

All Figures

$\begin{figure} \par {\includegraphics[width=8.1cm,clip]{0493fig1.ps} } \end{figure}$ Figure 1: The SFR in the Universe as a function of the redshift. The dashed line represents the SFR derived from numerical simulations for $z \ge 5$ (Gnedin & Ostriker 1997). The solid line shows the SFR at the z < 5 region based on observational estimates (Rowan-Robinson 1999, 2001). The transition between the two regions has been smoothed.
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In the text

$\begin{figure} \par {\includegraphics[width=8.7cm,clip]{0493fig2.ps} }\end{figure}$ Figure 2: Differential peak photon flux distribution of GRBs. The solid curve shows the differential peak photon flux distribution if all redshifts are considered, i.e., $N_{\rm GRB}(P)$ . The dashed curves represent the differential peak photon flux distribution of GRBs when only GRBs with $z > z_{\rm edge}$ are taken into account, i.e., $N_{\rm GRB}(P,z_{\rm edge})$ . The intention of this figure is to show how the Gaussian-like solid curve displaces leftwards (low P values) as $z_{\rm edge}$ increases. The dashed lines plotted in the figure are shown as an example, using arbitrary values of $z_{\rm edge}$ , not marked for simplicity. As $z_{\rm edge}$ increases the closer GRBs (and therefore larger P bursts) are left out (right tail of the Gaussian-like distribution). The vertical lines represent the detection thresholds for the different missions/instruments, showing the arrows the detectability region.
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In the text

$\begin{figure} \par {\includegraphics[width=8.6cm,clip]{0493fig3.ps} }\end{figure}$ Figure 3: Relative number of detections as a function of the redshift. This plot shows, for several high-energy missions/instruments, the fraction of the detected GRBs that have a redshift larger than $z_{\rm edge}$ .
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In the text

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{0493fig4.ps} } \end{figure}$ Figure 4: The GRB detection ratio of INTEGRAL/IBIS with respect to SWIFT/BAT as a function of the GRB population redshift. $f_{ {\rm INTEGRAL/IBIS}-{\rm SWIFT/BAT}}$ increases with redshift because of the better sensitivity for high redshift GRBs of INTEGRAL/IBIS. At redshifts $z\protect \la 5.6$ the larger field of view of SWIFT dominates, making $f_{ {\rm INTEGRAL/IBIS}-{\rm SWIFT/BAT}}< 1$ .
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In the text

$\begin{figure} \par {\includegraphics[width=8.3cm,clip]{0493fig5.ps} } \end{figure}$ Figure 5: The evolution of the observed flux of a typical GRB afterglow (GRB 000301c) when it is redshifted from z=2.0404 (spectroscopic redshift; Jensen et al. 2001) up to z=22. The circles show the photometric measurements of the afterglow from the U to the K-band, taken 1.06 days after the GRB. The dashed line represents the SED fitted to the photometric points (see main text). The rhomboids, triangles and squares show the JHK-band sensitivities (5 $\sigma$ ) foreseen for the future GTC 10 m telescope (+ EMIR instrument), for several exposure times. Afterglows can be detected in the three JHK bands up to z=9, with only a exposure time of 900 s per filter. K-band counterparts would be detectable up to $z\sim 17$ . For $T_{\exp} >$ 900 s the detectability of the GRB 000301c afterglow with the GTC (+EMIR) is dominated by the Ly- $\alpha$ blanketing effect, and is basically independent of the exposure time employed in the observations. The Ly- $\alpha$ blanketing absorption has been modeled following Madau (1995).
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In the text

$\begin{figure} \par {\includegraphics[width=8.1cm,clip]{0493fig1.ps} } \end{figure}$	Figure 1: The SFR in the Universe as a function of the redshift. The dashed line represents the SFR derived from numerical simulations for $z \ge 5$ (Gnedin & Ostriker 1997). The solid line shows the SFR at the z < 5 region based on observational estimates (Rowan-Robinson 1999, 2001). The transition between the two regions has been smoothed.
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$\begin{figure} \par {\includegraphics[width=8.6cm,clip]{0493fig3.ps} }\end{figure}$	Figure 3: Relative number of detections as a function of the redshift. This plot shows, for several high-energy missions/instruments, the fraction of the detected GRBs that have a redshift larger than $z_{\rm edge}$ .
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