We present a study of the star formation ( SF ) region G38.9-0.4 using publicly available multiwavelength Galactic Plane surveys from ground- and space-based observatories .
This region is composed of four bright mid-IR bubbles and numerous infrared dark clouds .
Two bubbles , N 74 and N 75 , each host a star cluster anchored by a single O9.5V star .
We identified 162 young stellar objects ( YSOs ) and classify 54 as stage I , 7 stage II , 6 stage III , and 32 ambiguous .
We do not detect the classical signposts of triggered SF , i.e. , star-forming pillars or YSOs embedded within bubble rims .
We conclude that feedback-triggered SF has not occurred in G38.9-0.4 .
The YSOs are preferentially coincident with infrared dark clouds .
This leads to a strong correlation between areal YSO mass surface density and gas mass surface density with a power law slope near 1.3 , which closely matches the Schmidt-Kennicutt Law .
The correlation is similar inside and outside the bubbles and may mean that the SF efficiency is neither enhanced nor supressed in regions potentially influenced by stellar feedback .
This suggests that gas density , regardless of how it is collected , is a more important driver of SF than stellar feedback .
Larger studies should be able to quantify the fraction of all SF that is feedback-triggered by determining the fraction SF , feedback-compressed gas surrounding H ii regions relative to that already present in molecular clouds .