Abstract:
In this study we investigated the effects of external trigger on the characteristics of young stellar objects
(YSOs) associated with cometary globules (CGs). We made
optical spectroscopy of stars associated with star-forming
CGs. We find that the masses of the most massive stars associated with CGs are correlated with the masses of the parent cloud but they are systematically larger than expected
for clouds of similar mass from the relation Mmax-star =
0.33Mcl°·⁴³ given by Larson (Mon. Not. R. Astron. Soc.
200:159, 1982). We have also estimated the luminosities of
the IRAS sources found associated with CGs as a function
of cloud mass and then compared them with those of the
IRAS sources found associated with isolated opacity class 6
clouds (isolated and relatively away from large star forming
regions). We find that the luminosities of IRAS sources associated with CGs are larger than those of the opacity class
6 clouds. These findings support results from recent simulations in which it was shown that the Radiation Driven
Implosion (RDI) process, believed to be responsible for the
cometary morphology and star formation, can increase the
luminosity 1–2 orders of magnitudes higher than those of
protostars formed without external triggering due to an in-
crease in accretion rates. Thus implying that the massive
stars can have profound influence on the star formation in
clouds located in their vicinity.