We present a multi-wavelength study of the IR bubble G24.136+00.436 .
The J=1-0 observations of ^ { 12 } CO , ^ { 13 } CO and C ^ { 18 } O were carried out with the Purple Mountain Observatory 13.7 m telescope .
Molecular gas with a velocity of 94.8 km s ^ { -1 } is found prominently in the southeast of the bubble , shaping as a shell with a total mass of \sim 2 \times 10 ^ { 4 } M _ { \odot } .
It is likely assembled during the expansion of the bubble .
The expanding shell consists of six dense cores .
Their dense ( a few of 10 ^ { 3 } cm ^ { -3 } ) and massive ( a few of 10 ^ { 3 } M _ { \odot } ) characteristics coupled with the broad linewidths ( > 2.5 km s ^ { -1 } ) suggest they are promising sites of forming high-mass stars or clusters .
This could be further consolidated by the detection of compact HII regions in Cores A and E. We tentatively identified and classified 63 candidate YSOs based on the Spitzer and UKIDSS data .
They are found to be dominantly distributed in regions with strong emission of molecular gas , indicative of active star formation especially in the shell .
The HII region inside the bubble is mainly ionized by a \sim O8V star ( s ) , of the dynamical age \sim 1.6 Myr .
The enhanced number of candidate YSOs and secondary star formation in the shell as well as time scales involved , indicate a possible scenario of triggering star formation , signified by the “ collect and collapse ” process .