1,709 research outputs found
The ISM Interactions of a Runaway LBV Nebula in the LMC
New observations of the Magellanic Cloud Luminous Blue Variable candidate
S119 (HD269687) show the relationship of the star to its environs. Echelle
spectroscopy and high-resolution HST imagery reveal an expanding bubble
centered on the star. This bubble appears in both Halpha and [NII] and is
noticeably brighter on the near (blue-shifted) side. The systemic velocity of
both the expanding bubble and the star itself (as seen by the very broad Halpha
emission feature in the stellar spectrum) is V_hel=160 km/s whereas the
velocity of the superposed LMC ISM is 250-300 km/s. ISM absorption features
seen in FUSE spectra reveal components at both stellar and LMC velocities. Thus
we conclude that S119 is located within the LMC ISM and that the bubble is
interacting strongly with the ISM in a bow shock.Comment: 5 pages in EmulateApJ format, 3 figures Accepted by ApJL See
http://fuse.pha.jhu.edu/~danforth/s119
Star Formation in the LMC: Gravitational Instability and Dynamical Triggering
Evidence for triggered star formation is difficult to establish because
energy feedback from massive stars tend to erase the interstellar conditions
that led to the star formation. Young stellar objects (YSOs) mark sites of {\it
current} star formation whose ambient conditions have not been significantly
altered. Spitzer observations of the Large Magellanic Cloud (LMC) effectively
reveal massive YSOs. The inventory of massive YSOs, in conjunction with surveys
of interstellar medium, allows us to examine the conditions for star formation:
spontaneous or triggered. We examine the relationship between star formation
and gravitational instability on a global scale, and we present evidence of
triggered star formation on local scales in the LMC.Comment: 6 pages, 6 figures, IAU Symposium 237, Triggered Star Formation in a
Turbulent Medium, eds. Elmegreen and Palou
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