We present an analysis of multi-wavelength observations from various datasets and Galactic plane surveys to study the star formation process in the W42 complex .
A bipolar appearance of W42 complex is evident due to the ionizing feedback from the O5-O6 type star in a medium that is highly inhomogeneous .
The VLT/NACO adaptive-optics K and L ^ { \prime } images ( resolutions \sim 0 \farcs 2–0 \farcs 1 ) resolved this ionizing source into multiple point-like sources below \sim 5000 AU scale .
The position angle \sim 15 \arcdeg of W42 molecular cloud is consistent with the H-band starlight mean polarization angle which in turn is close to the Galactic magnetic field , suggesting the influence of Galactic field on the evolution of the W42 molecular cloud . Herschel sub-millimeter data analysis reveals three clumps located along the waist axis of the bipolar nebula , with the peak column densities of \sim 3–5 \times  10 ^ { 22 } cm ^ { -2 } corresponding to visual extinctions of A _ { V } \sim 32–53.5 mag .
The Herschel temperature map traces a temperature gradient in W42 , revealing regions of 20Â K , 25Â K , and 30–36Â K . Herschel maps reveal embedded filaments ( length \sim 1–3 pc ) which appear to be radially pointed to the denser clump associated with the O5-O6 star , forming a hub-filament system .
512 candidate young stellar objects ( YSOs ) are identified in the complex , \sim 40 % of which are present in clusters distributed mainly within the molecular cloud including the Herschel filaments .
Our datasets suggest that the YSO clusters including the massive stars are located at the junction of the filaments , similar to those seen in Rosette Molecular Cloud .