Author(s): , , , , , , ,
Institution(s): 1. Harvard-Smithsonian CfA, 2. Iowa State University, 3. NOAO, 4. University of Chile
Understanding the rate and history of star formation within individual molecular clouds requires a knowledge of the time scales involved in the star formation process, and the ability to determine the age of young stellar populations. I have studied several star formation rate tracers in a variety of high-mass Milky Way star forming regions and find that different methods can produce dramatically different star formation rate measurements for an individual cloud. Methods that rely on characterizing the stellar population are sensitive to uncertainties in the age and evolutionary timescale of young stellar objects. When comparing clouds, relative age indicators such as the ratio of protostars to stars with disks are also affected by uncertainties in fundamental physical parameters including the distance to the star forming regions. I will present my investigation into these uncertainties and the conclusions we can draw about star formation rate and star formation histories in different Galactic environments, from nearby, relatively low-mass star forming regions through compact massive clouds that form starburst clusters.