Context :

Aims : We search for evidence of a relation between properties of young stellar objects ( YSOs ) and their parent molecular clouds to understand the initial conditions of high-mass star formation .

Methods : A sample of 135 sources was selected from the Infrared Astronomical Satellite ( IRAS ) Point Source Catalog , on the basis of their red color to enhance the possibility of discovering young sources .
Using the Kölner Observatorium für SubMillimeter Astronomie ( KOSMA ) 3-m telescope , a single-point survey in ^ { 13 } CO J = 2 – 1 was carried out for the entire sample , and 14 sources were mapped further .
Archival mid-infrared ( MIR ) data were compared with the ^ { 13 } CO emissions to identify evolutionary stages of the sources .
A ^ { 13 } CO observed sample was assembled to investigate the correlation between ^ { 13 } CO line width of the clouds and the luminosity of the associated YSOs .

Results : We identified 98 sources suitable for star formation analyses for which relevant parameters were calculated .
We detected 18 cores from 14 mapped sources , which were identified with eight pre-UC H ii regions and one UC H ii region , two high-mass cores earlier than pre-UC H ii phase , four possible star forming clusters , and three sourceless cores .
By compiling a large ( 360 sources ) ^ { 13 } CO observed sample , a good correlation was found between the ^ { 13 } CO line width of the clouds and the bolometric luminosity of the associated YSOs , which can be fitted as a power law , \lg ( \Delta V _ { 13 } / km s ^ { -1 } ) = ( -0.023 \pm 0.044 ) + ( 0.135 \pm 0.012 ) \lg % ( L _ { bol } / L _ { \odot } ) .
Results show that luminous ( > 10 ^ { 3 } L _ { \odot } ) YSOs tend to be associated with both more massive and more turbulent ( \Delta V _ { 13 } > 2 km s ^ { -1 } ) molecular cloud structures .

Conclusions :