All Figures

$\begin{figure} \par\includegraphics[width=16.5cm,clip]{0447fig1.eps} \end{figure}$ Figure 1: J, H, and Ks images of the W49A region. The main star cluster begins to appear in the H image, but is readily apparent in the Ks image, as are many diffuse nebular features. North is up and East to the left.
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In the text

$\begin{figure} \par\includegraphics[width=6.4cm,clip]{0447fig2.eps} \end{figure}$ Figure 2: Color-color diagram for our survey. The main sequence and giant tracks are overplotted, as is a light solid line indicating the reddening sequence for the bluest, hottest stars. A Rieke & Lebofsky (1985) extinction law was used.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig3.eps}\end{figure}$ Figure 3: The K-band luminosity function for all objects. The binsize is 0.3 mag. We show the 80% completeness limit as a dashed line.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig4.eps}\end{figure}$ Figure 4: The K-band luminosity function for objects with $H-K \ge 1.2$ which are likely to be associated with the W49A star-forming region (see text). The binsize is 0.3 mag. The dashed histogram indicates objects within $45\hbox {$^{\prime \prime }$ }$ of our adopted center of Cluster 1. We include the 80% completeness limit for the entire field as a dashed line, and for the inner $500\times 500$ pixels as a dotted line.
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In the text

$\begin{figure} \par\includegraphics[width=6.9cm,clip]{0447fig5.eps} \end{figure}$ Figure 5: $(H-K{\rm s})$ Color-magnitude diagram showing the limits for an extinction-limited sample. We chose an H-K=2.0 limit to cover a reasonable range of reddening. For the entire field, our 80% completeness limits are H=18.7 and $K{\rm s}=17.2$ . However, crowding in the center of the image reduces this to H=18.2, $K{\rm s}=16.7$ Thus at $K{\rm s}=16.2$ , H-K=2, we are above 80% completeness for everything brighter and bluer than these limits. This defines the bottom-right corner of the overplotted polygon. The slope of the bottom edge is determing by the extinction law, and the H-K=1.2 limit is described in Sect. 4.1.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig6.eps}\end{figure}$ Figure 6: Extinction-limited K-band luminosity function for Cluster 1. The binsize is 0.5 mag.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig7.eps}\end{figure}$ Figure 7: Extinction-limited extinction-corrected K-band luminosity function for Cluster 1. The binsize is 0.5 mag. The slope of the fitted line is $0.30 \pm 0.16$ . We used a larger bin size to take into account extinction correction errors caused by intrinsic $H-K{\rm s}$ colors.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig8.eps} \end{figure}$ Figure 8: Extinction-limited K-band luminosity function for all objects. The binsize is 0.5 mag.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig9.eps}\end{figure}$ Figure 9: Extinction-limited extinction-corrected K-band luminosity function for all objects. The binsize is 0.5 mag. The slope of the fitted line is $0.37 \pm 0.07$ . We used a larger bin size to take into account extinction correction errors caused by intrinsic $H-K{\rm s}$ colors.
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In the text

$\begin{figure} \par\includegraphics[width=16.2cm,clip]{0447fig10.eps} \end{figure}$ Figure 10: Mass functions from the extinction-limited extinction-corrected sample shown in Fig. 9. In the left panel we transformed the Ks magnitudes of the luminosity function into mass. The mass bin sizes thus depend on the mass-magnitude relationship. The fitted slope is $-1.60 \pm 0.28$ . In the right panel, masses were derived based on the Ks magnitudes for individual stars, and the log(M) bins are 0.1. The fitted slope is $-1.64\pm 0.28$ . We do not find evidence for a top-heavy IMF.
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In the text

$\begin{figure} \par\includegraphics[width=6.6cm,clip]{0447fig11.eps} \end{figure}$ Figure 11: (H-K) Color-magnitude diagram showing the limits for identifying candidate massive stars. The solid line represents the reddening line for a $4\times 10^{5}$ yr $20~ M_{\odot}$ star (Lejeune & Schaerer 2001), from A_K=0 to A_K=5. The dotted line represents the H-K=1.2 limit described in Sect. 4.1.
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In the text

$\begin{figure} \par\includegraphics[width=16.5cm,clip]{0447fig1.eps} \end{figure}$	Figure 1: J, H, and Ks images of the W49A region. The main star cluster begins to appear in the H image, but is readily apparent in the Ks image, as are many diffuse nebular features. North is up and East to the left.
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$\begin{figure} \par\includegraphics[width=6.4cm,clip]{0447fig2.eps} \end{figure}$	Figure 2: Color-color diagram for our survey. The main sequence and giant tracks are overplotted, as is a light solid line indicating the reddening sequence for the bluest, hottest stars. A Rieke & Lebofsky (1985) extinction law was used.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig3.eps}\end{figure}$	Figure 3: The K-band luminosity function for all objects. The binsize is 0.3 mag. We show the 80% completeness limit as a dashed line.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig6.eps}\end{figure}$	Figure 6: Extinction-limited K-band luminosity function for Cluster 1. The binsize is 0.5 mag.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig7.eps}\end{figure}$	Figure 7: Extinction-limited extinction-corrected K-band luminosity function for Cluster 1. The binsize is 0.5 mag. The slope of the fitted line is $0.30 \pm 0.16$ . We used a larger bin size to take into account extinction correction errors caused by intrinsic $H-K{\rm s}$ colors.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig8.eps} \end{figure}$	Figure 8: Extinction-limited K-band luminosity function for all objects. The binsize is 0.5 mag.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0447fig9.eps}\end{figure}$	Figure 9: Extinction-limited extinction-corrected K-band luminosity function for all objects. The binsize is 0.5 mag. The slope of the fitted line is $0.37 \pm 0.07$ . We used a larger bin size to take into account extinction correction errors caused by intrinsic $H-K{\rm s}$ colors.
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$\begin{figure} \par\includegraphics[width=6.6cm,clip]{0447fig11.eps} \end{figure}$	Figure 11: (H-K) Color-magnitude diagram showing the limits for identifying candidate massive stars. The solid line represents the reddening line for a $4\times 10^{5}$ yr $20~ M_{\odot}$ star (Lejeune & Schaerer 2001), from A_K=0 to A_K=5. The dotted line represents the H-K=1.2 limit described in Sect. 4.1.
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