Astronomy & Astrophysics

All Figures

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{4373fig1.eps} }\end{figure}$ Figure 1: The optical/NIR SED of the GRB 050724 host. The circles represent the measured magnitudes of the ${\it BVRIJ}_{\rm s}HK_{\rm s}$ bands in the AB system and corrected for Galactic reddening ( E(B-V)=0.613; Schlegel et al. 1998). The triangle shows the U-band upper limit. The plot shows the satisfactory fit achieved ( $\chi ^2/{\rm d.o.f.} = 0.90$ ) with an S86 IMF, an MW extinction law, and evolving metallicity. The derived stellar population age is 2.6 Gyr.
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In the text

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{4373fig2.eps} }\end{figure}$ Figure 2: The distribution of the dominant stellar population ages for short- and long-duration GRB hosts. As shown, host galaxies of short GRBs (filled bins) tend to have older stellar populations than long GRB hosts. According to the WMWW test, the probability that the two samples (short and long GRB host galaxies) share the same parent median age is only $2.5\times 10^{-3}$ . The arrows indicate that the stellar ages assumed for GRB 050509B, GRB 050709, and GRB 050813 are probably underestimated.
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In the text