Star formation rates (top panel) and central gas masses (bottom panel) for all systems in isolation with R_g = R_d for models A (orange), B (red), C1 (blue), D1 (black), and with R_g = 2R_d for models A (purple) and C1 (green). Note that although model C1 (blue) is less massive than B (red), the star formation rate is higher for C1 because it has a higher gas mass in the center due to its higher initial gas fraction.