SIMBAD references

1995A&A...303..901T - Astronomy and Astrophysics, volume 303, 901-913 (1995/11-3)

The W 3 core: masses, densities, sizes and kinematics.


Abstract (from CDS):

The core of the W 3 molecular cloud has been mapped in a 3'x2' region in the J=2-1 transition of C18O and the J=3-2 and J=5-4 transitions of C34S with angular resolutions of 11", 17" and 10", respectively, using the IRAM 30-m telescope. The W 3 core consists of two regions separated by 75" (=0.85pc at 2.3kpc). The region associated with W 3 IRS 5 has an average vlsr≃-39km/s and a mass of 800M. The other, more extended region associated with W 3 IRS 4 has an average vlsr≃-43km/s and a mass of 1500M. The IRS 4 region is resolved into four smaller clumps. One of these is close to, but not coincident with, the submillimeter continuum peak SMS 3; another is very close to IRS 4 and SMS 2. The IRS 5 region is barely resolved into four clumps. There is a clump centered on IRS 5. From the C18O data, the H2 column densities of the clumps have been determined. From a Large Velocity Gradient analysis of the C34S 3-2/5-4 ratios the H2 densities and masses were estimated; these are compared with general results from the virial theorem. Dynamics are investigated using velocity channel maps. Over a 70" region in Declination, the vlsr of the IRS 4 region changes from -42km/s in the southern part to -46km/s in the northern part. For the northern part of IRS 4, over 70" in Right Ascension, there is a change from -41km/s in the western part to -47km/s in the eastern part. This velocity change is opposite to the sense of galactic rotation; the gradient is 9km/s/pc. For the IRS 5 region, there is a similar change in vlsr with Dec., but only a small change with R.A. Considering the presence of a magnetic field of 100µG towards IRS 4 and the striking change in radial velocity, we speculate that "magnetic braking" dominates the dynamics in the IRS 4 region. Our C18O and C34S results are compared with the abundances of other molecular species and show that the IRS 4 and IRS 5 regions have distinctly different chemistry.

Abstract Copyright:

Journal keyword(s): ISM: clouds - ISM: molecules - radio lines: ISM - ISM: magnetic fields - ISM: individual: W 3

Simbad objects: 15

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