|
We present the results of an unbiased spectroscopic K-band survey
comprising 212 stars toward the young cluster in M17. While there
are 9 stars with the CO band head in emission we find 103
stars which show this feature in absorption. Many of the CO
absorption sources are located in a region of ongoing star
formation; additionally, more than half of them emit X-rays and/or
have infrared excess. We therefore suggest that CO absorption is a
common feature during early stellar evolution and a sign for heavily
accreting protostars. Furthermore, sources with strong infrared
excess are generally lacking any spectral features, indicating that
veiling by circumstellar dust is a dominant process. Estimates of the
intrinsic luminosity suggest that these sources are progenitors of
intermediate and high-mass stars.
|
