High spatial resolution isotopic CO and CS observations of M17 SW - The clumpy structure of the molecular cloud core
J. Stutzki, R. Guesten;
ApJ, 1990, 356, 513
ABSTRACT:This paper presents high-angular-resolution maps of the M17 SW cloud core in the C(O-18) J = 2-1 (13 arcsec FWHM beam) and C(S-34) J = 2-1 (27 arcsec
FWHM), 3-2 (17 arcsec FWHM) lines obtained with the IRAM 30 m telescope.
These
maps directly reveal the clumpy structure of the entire cloud core down to
linear scales of 13 arcsec and below.
Individual clumps have line widths as
small as 0.5 km/s, compared to a line width of 3-5 km/s observed with lower
angular resolution in the same lines.
The C(O-18) 2-1 line reaches a peak
brightness temperature of 24 K in the 13-arcsec beam and is probably slightly
optically thick in several locations.
Spectra in the more abundant CO isotopes
obtained toward several selected positions show strong self-absorption
notches and peak brightness temperatures in between these notches of about 100 K.
KEYWORDS: carbon monoxide, molecular clouds, nebulae, spatial resolution, sulfides, abundance, astronomical maps, brightness temperature, carbon compounds, emission spectra, line spectra, spectral line width
CODE: stutzki90