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Galactic HII Regions are normally
found deeply embedded within the giant interstellar cloud complexes,
being well-known signposts of the massive star formation activity.
In this kind of environment, near-infrared
(NIR) photometry is a powerful tool to probe deep into the obscuring
dust, allowing the analysis of the newly formed stellar population.
Furthermore, the magnetic field is probably an important physical
property of
these regions. Indeed, its sky-projected components can be mapped
from the interstellar polarization generated by the aligned dust
grains.
In this talk I will present some preliminary results of our recent
optical polarimetric survey (using CTIO's 0.9m telescope),
particularly toward the Vela Molecular Ridge (VMR), which is a very
interesting site where star formation is still ongoing. In fact, the
distortion of the projected interstellar magnetic field lines,
probably generated by the presence of expanding HII regions, are
clearly seen toward some areas. Specifically in the direction
of the RCW 41 HII region (in the VMR), deep near-infrared images
from the NTT 3.6m telescope (La Silla) are being used to study the
photometric properties of the embedded young stellar population.
These data reveal the presence of several YSO's (young stellar
objects), probably T Tauri stars, indicating a mean cluster age of
approximately 2.5 million years.
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