Cluster Luminosity Function

Figure 5 shows the luminosity function for the cluster and the control field. The histogram with the horizontal line shading is the histogram of the cluster, and the histogram with the diagonal line shading is that of the control field. We can do a bin by bin subtraction of these histograms to make a statistical correction for the field contamination. However, it is easier to observe the distribution between the cluster and the control luminosity functions if we plot them separately.

Observing these histograms show that the stars in the control field are, on average, dimmer than the stars in the cluster. It is possible that this means the gas and dust within the cluster is extinguishing the dimmer background stars located at a distance greater than the cluster itself. We already established that the upper limit to the distance of the furthest observed star in our control frame is 1200pc away. All the stars that lie between this line and the 320pc line in Figure 3(b) show the background stars that are located farther than the cluster and it shows the statistical population of the stars that are obscured by the interstellar dust in the cluster.

The luminosity function for our cluster also gives a good description of the distribution of the stellar spectral types in the main sequence. Since IC348 is a relatively young cluster, it will contain many of the higher mass stars which have short lifetimes. Additionally, we can detect low luminosity brown dwarfs within our distribution when the cluster is at a young age because brown dwarfs are brightest when they are young in age. Using this distribution of stars, we can determine the age of the cluster and the mass of the stars within the cluster.

Figure 5: Here is a plot of the Luminosity Functions for our cluster and the control field. The histogram with the horizontal lines is that of the cluster and the histogram with the diagonal lines is for the control field. Notice that the stars in the control field are generally at much higher magnitudes, suggesting that we are observing background stars in the control field that are further away than the stars in the cluster.