Outflows from young stellar objects have been identified as a possible source of turbulence in molecular clouds .
To investigate the relationship between outflows , cloud dynamics and turbulence , we compare the kinematics of the molecular gas associated with NGC 1333 , traced in ^ { 13 } CO ( 1-0 ) , with the distribution of young stellar objects ( YSOs ) within .
We find a velocity dispersion of \sim 1 - 1.6 km/s in ^ { 13 } CO that does not significantly vary across the cloud , and is uncorrelated with the number of nearby young stellar outflows identified from optical and submillimeter observations .
However , from velocity channel maps we identify about 20 depressions in the ^ { 13 } CO intensity of scales \gtrsim 0.1 - 0.2 pc and velocity widths 1 - 3 km/s .
The depressions exhibit limb brightened rims in both individual velocity channel maps and position velocity diagrams , suggesting that they are slowly expanding cavities .
We interpret these depressions to be remnants of past YSO outflow activity : If these cavities are presently empty , they would fill in on time scales of \sim 10 ^ { 6 } yr .
This can exceed the lifetime of a YSO outflow phase , or the transit time of the central star through the cavity , explaining the absence of any clear correlation between the cavities and YSO outflows .
We find that the momentum and energy deposition associated with the expansion of the cavities is sufficient to power the turbulence in the cloud .
In this way we conclude that the cavities are an important intermediate step between the conversion of YSO outflow energy and momentum into cloud turbulent motions .