Poster Title: Physical limits to the validity of synthesis models: The Lowest Luminosity Limit.
Abstract: Miguel Cerviņo & Valentina Luridiana
Abstract: In this work we establish a necessary condition for the application of stellar population synthesis models to observed star clusters. Such condition is expressed by the requirement that the total luminosity of the cluster modeled be larger than the contribution of the most luminous star included in the assumed isochrones, which is referred to as the Lowest Luminosity Limit (LLL).
We have obtained the LLL for a wide range of ages (5 Myr to 20 Gyr) and metallicities (Z=0 to Z=0.019), and, using the results of evolutionary synthesis models, we have also obtained the minimal cluster mass associated to the LLL, which is the mass value below which the observed colors are severely biased with respect to the predictions of synthesis models. we find that, the minimal mass is larger in near infrared bands (Mmin around 10$^4$ and 10$^5$ Mo for the K band), implying that severe sampling effects may affect the infrared emission of many observed stellar clusters.
Finally, we extensively discuss the advantages and the drawbacks of our method: it is, on one hand, a very simple criterion for the detection of severe sampling problems, that bypasses the need for sophisticated statistical tools; on the other hand, it is not very sensitive, and it does not identify all the objects in which sampling effects are important and a statistical analysis (like Monte Carlo simulations) is required. As such, it defines a condition necessary but not sufficient for the application of synthesis models to observed clusters.
Link to poster: N/A