Are interstellar toroids the focusing agent of the bipolar molecular outflows?

8-13 µm Spectropolarimetry of Star Formation Regions

“…Takano et al 1984; Kawabe et al 1984;Torrelles et al 1983). The observed transitions in these molecules require high densities for their excitation, and so are ideal for probing such regions in areas of star formation.…”

“…Making use of observations of the type listed above, contained in the literature, we derived position angles of bipolar outflows (Lada 1985;Fukui 1989 and references therein;Mitchell et al 1991) and disks (Walker et al 1990;Minchin et al 1991bMinchin et al , 1991cTorrelles et al 1983;Hayashi et al 1987;Scoville et al 1986;Plambeck et al 1982) for several objects. We then compared the geometry of such structures with our 10 J.Lm spectropolarimetric observations, a process which defines the direction of the magnetic field on the plane of the sky.…”

“…In some cases, a disk or torus of material has been observed around the source, extending in a direction perpendicular to the axis of the outflow (e.g. Torrelles et al 1983;Takano et al 1984). In a study of the K band polarisation of ten infrared sources in bipolar CO outflows, Sato et al (1985) found that the position angle of the polarisation is predominantly perpendicular to the outflow, and parallel to the disk (four sources).…”

Star formation in molecular disks

“…If jets are magnetically collimated, it is essential to understand why collimation of inner hot gas is so much better than the molecular component (Pudritz and Norman 1986h). If geometrically thick tori collimate the flow (Torrelles et al 1983), then rather special structures will be required to collimate outflow over the scales 10 15 -10 17 cm. Ulrich and Knapp (1985) have obtained moderate dispersion spectra (AV ~ 13 and 30 km s *) for Ha, Hß, Na D, and He I X5846 line profiles for 58 Orion population stars.…”

“…They include: (1) 13 CO (J = 1-0 transitions) observations of NGC 7538, Cep A, and K3-50A with the high-resolution (7") Owens Valley millimeter wave observatory (Sargent et al 1986); (2a) NH 3 ((J,K) = (1,1) inversion transition at 23.69 GHz) observations of 15 sources of bipolar outflow in which nine showed detectable emission (L1551, HH 26IR, NGC 2071, Mon R2, GGD 12-15, GL 961, S 106, V645 Cyg, NGC 7129). The Haystack 37-m radio telescope was used and the beam size was 1.4 (Torrelles et al 1983). (2b) Takano et al (1986) mapped NGC 2071 at Bonn using 40" resolution.…”