In the direction of l = 17 \arcdeg .6 – 19 \arcdeg , the star-forming sites Sh 2-53 and IRAS 18223-1243 are prominently observed , and seem to be physically detached from each other .
Sh 2-53 has been investigated at the junction of the molecular filaments , while a larger-scale environment of IRAS 18223-1243 remains unexplored .
The goal of this paper is to investigate the star formation processes in the IRAS site ( area \sim 0 \arcdeg .4 \times 0 \arcdeg .4 ) .
Based on the GRS ^ { 13 } CO line data , two molecular clouds , peaking at velocities of 45 and 51 km s ^ { -1 } , are found .
In the position-velocity plots , a relatively weak ^ { 13 } CO emission is detected at intermediate velocities ( i.e .
47.5–49.5 km s ^ { -1 } ) between these two clouds , illustrating a link between two parallel elongated velocity structures .
These clouds are physically connected in both space and velocity .
The MAGPIS data at 20 cm trace free-free continuum emission toward the IRAS 18223-1243 source .
Using the Spitzer and UKIDSS photometric data , we have identified infrared-excess young stellar objects ( YSOs ) , and have observed their groups toward the intersection zones of the clouds .
IRAS 18223-1243 is also spatially seen at an interface of the clouds .
Considering these observational findings , we propose the onset of the collision of two clouds in the IRAS site about 1 Myr ago , which triggered the birth of massive star ( s ) and the YSO groups .
A non-uniform distribution of the GPIPS H-band starlight mean polarization angles is also observed toward the colliding interfaces , indicating the impact of the collision on the magnetic field morphology .