Abstract
view Abstract Citations (52) References (44) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Dense Cores in Dark Clouds. IX. Observations of 13CO and C 18O in Vela, Chamaeleon, Musca, and the Coalsack Vilas-Boas, J. W. S. ; Myers, P. C. ; Fuller, G. A. Abstract One hundred one condensations with average optical size less than 7 min and visual extinction greater than 2.5 mag have been selected from European Southern Observatory (ESO) J plates, extinction maps, and catalogs of southern hemisphere dark clouds for observation in the (13)CO and C(18)O J = 1 goes to 0 transitions. These regions are condensations in the dark molecular clouds Musca, Coalsack, Chamaeleon II, Chamaeleon III, and cometary globules in Vela and Gum nebula. A search for IRAS point sorces having colors of young stellar objects shows that these condensations have at most seven associated young stellar objects-far fewer than in Taurus and Ophiuchus. These 101 condensations generally have lower (13)CO and C(18)O line intensity, C(18)O optical depth, and (13)CO line width than do 90 condensations in Taurus, Ophiuchus, and Cepheus. Similarly, 47 of these southern condensations having star-count estimates of visual extinction generally have less extinction than do the 19 condensations in Taurus having extinction estimated by the same method. The C(18)O to (13)CO line-width ratio for the cometary globules in the Vela ragion is greater than for the other clouds, indicating that the (13)CO line width observed toward dark cloud condensations is related to the more extended and less dense intercondensation gas. Radial velocities suggest that the system of Vela globules has velocity dispersion 4.7 km/s, which is at least 2 times greater than the dispersion determined from formalhyde observations. The Musca filament has velocities which are slightly higher-by approximately 0.5 km/s-in the center than at the ends of the filament. Chamaeleon III has a 0.2 km/s velocity gradient and Chamaeleon II has no indication of velocity gradients. The Chamaeleon clouds and the Musca filament appear close to virial equilibrium. Publication: The Astrophysical Journal Pub Date: September 1994 DOI: 10.1086/174628 Bibcode: 1994ApJ...433...96V Keywords: Carbon Dioxide; Gas Dynamics; Interstellar Gas; Kinematics; Molecular Clouds; Molecular Spectra; Radio Astronomy; Astronomical Spectroscopy; Carbon 13; Ophiuchi Clouds; Radio Telescopes; Astronomy; ISM: CLOUDS; ISM: KINEMATICS AND DYNAMICS; ISM: MOLECULES full text sources ADS | data products SIMBAD (113) Related Materials (12) Part 1: 1983ApJ...264..517M Part 2: 1983ApJ...266..309M Part 3: 1983RMxAA...7..238M Part 4: 1983ApJ...270..105M Part 5: 1983ApJ...270..589B Part 6: 1988ApJ...324..907M Part 7: 1991ApJ...376..561M Part 8: 1992ApJ...384..523F Part 9: 1993ApJ...406..528G Part 11: 1994ApJ...433..117L Part 12: 1998ApJ...506..743B Part 13: 2000ApJ...532.1038V
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