In many symbiotic stars there appear broad wings around Hα, of which the formation mechanisms proposed thus far include a fast outflow, motion of the inner accretion disc, electron scattering and Raman scattering of Lyβ. We adopt a Monte Carlo technique to simulate the Raman scattering of ultraviolet photons that are converted into optical photons around Hα, forming broad wings, and compute its polarization. Noting that many symbiotic stars exhibit a bipolar nebular morphology and polarization flip in the red‐wing part of the Raman‐scattered O vi features, we assume that the neutral scattering region is composed of two components. The first component is a static cylindrical shell with finite thickness; and the second component is a finite slab that is moving away with velocity vp= 100 km s−1 along the symmetry axis of the first component. The cylindrical shell component yields polarization in the direction parallel to the cylinder axis. The strongest polarization is obtained in the limit where the height of the cylinder approaches zero and the scattering region effectively becomes a circular ring. As the height of the cylinder increases, the resultant polarization decreases and becomes negligible in the limit of the infinite cylinder. The polarization near the line centre is weaker than in the far‐wing regions because of the large Rayleigh scattering numbers arising from the large scattering cross‐sections near the line centre. The receding polar scattering component produces strong polarization in the direction perpendicular to the cylinder axis. In the presence of a Lyβ emission‐line component with an equivalent width ∼ 0.5 Å, the polarized flux exhibits a local maximum at λ= 6578 Å that corresponds to a recession velocity 6.4vp relative to Hα. When both of the scattering components co‐exist, the polarization is characterized by weak parallel polarization near the line centre and strong perpendicular polarization in the red part. We discuss the observational implications of our computation.

We present the results of 12 CO J = 2 → 1 observations of the X-ray bright giant shell complex 30 Doradus in the Large Magellanic Cloud (LMC) using the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). This is the one of the largest H II complexes in the Local Group. We compare the 12 CO J = 2 → 1 observations against previously taken 12 CO J = 4 → 3 observations and analyze the spatial distribution of young stellar objects (YSO's) within the cloud using the Spitzer IRAC observations of the 30 Doradus complex. Both peaks of 12 CO J = 2 → 1 and J = 4 → 3 emitting clouds coincide with the densest region of the filaments where multiple shells are colliding. We find that the YSO's are clustered in the southern ridge of the warm and dense molecular gas clouds traced by 12 CO J = 4 → 3, indicating a filamentary structure of star formation throughout the 30 Doradus. We also find that some of Class I YSO's candidates which are likely to be Associated with a high-velocity component of 12 CO J = 4 → 3 emitting clouds are present. This is a bona fide place where the triggered star formation had happened and newly formed stars may have produced such a high-velocity outflow interacting with the surrounding molecular cloud material.