All Figures

$\begin{figure} \par\includegraphics[width=18cm,clip]{figure1_new_ref.epsf} \end{figure}$ Figure 1: NGC 5253 in Ks (left) and L' (right) bands. North is up and East is left. Coordinates refer to the J2000 equinox. The field of view of the image is 40 $^{\prime \prime }$ . The intensity scale on the Ks band has been chosen to clearly show the brightest clusters. The actual image is much deeper than this display. The clusters are labeled as in C97. As the numbers in C97 correspond to a brightness scale, these images clearly show the dramatic changes occurring in the spectral energy distribution of most clusters in NGC 5253. Cluster 5a is the relatively bright object in the L' image North-East of Cluster 5. Note that the intensity levels have been adjusted in the L' image to show clusters 1 and 3, but that cluster 5 is a point source in L' as well. Wavelet filtering of the L band image reveals that cluster 4 is responsible for the extension seen SW of cluster 5, though the statistical significance of this detection is too low to allow a reliable photometric measurement. At an even lower significance level, the same technique indicates the possible detection of a source around $\alpha =13^{\rm h}39^{\rm m}55.6^{\rm s}$ and $\delta =-31^{\circ }38'39\hbox {$^{\prime \prime }$ }$ , but at this very low level, this could very well be a false detection.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{ngc5253_vikl.ps} \end{figure}$ Figure 2: V-K/V-I and K-L/V-I color-color diagrams of the optically brightest clusters in NGC 5253. The solid black lines represent the output of Starburst99 for a instantaneous burst of $Z=1/5 ~Z_{\odot}$ . The solid lines with square points denote the change on the 1 Myr old point introduced by an increasing amount of dust at 1000 K. The arrows indicate the effect of 2 mag of visual extinction on the colors of cluster 5. The dashed line with open circles shows how a more proper treatment of all dust effects, extinction, scattering and emission, can affect the optical colors. Starting from the 1 Myr dust free Starburst99 model, we compute the colors of the same cluster embedded in a cocoon with the dust properties derived in Sect. 4, with the V optical depth increasing by 1 for each open circle, up to the cluster-5 best-fit value of 7. The photometric errors on the data points are of the same size of the symbols or smaller.
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In the text

$\begin{figure} \par\includegraphics[angle=0,width=17cm,clip]{new_fig_sed.eps} \end{figure}$ Figure 3: The spectral energy distribution of cluster 5 in NGC 5253. The 7-30 $\mu$ m range has been blown up for clarity in the inset. Symbols refer to the photometric source, from left to right: black plus signs correspond to the HST photometry, grey diamonds to the VLT/ISAAC data, grey triangles to the ISO data, black crosses in the 10 $\mu$ m range to the Frogel et al. (1982) data, black circles to the Moorwood & Glass (1982) data, the black square to the Gorjian et al. (2001) 11.7. $\mu$ m point, grey plus signs to IRAS data, the black cross in the submillimeter range to SCUBA data, the grey square to our SEST/SIMBA observation, and the black triangle is the OVRO upper limit. Horizontal error bars describe the filter bandwidths, while vertical error bars show the photometric errors, as quoted by the respective authors (see Table 3). In most cases, these bars are shorter than the symbol size. The dashed line is the best fitting DUSTY model.
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In the text