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arXiv · 1304.6520

The Mysterious Sickle Object in the Carina Nebula: A stellar wind induced bow shock grazing a clump?

Judith Ngoumou·Thomas Preibisch·Thorsten Ratzka·Andreas Burkert
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Abstract

Optical and near-infrared images of the Carina Nebula show a peculiar arc-shaped feature, which we call the "Sickle", next to the B-type star Trumpler 14 MJ 218. We use multi-wavelength observations to explore and constrain the nature and origin of the nebulosity. Using sub-mm data from APEX/LABOCA as well as Herschel far-infrared maps, we discovered a dense, compact clump with a mass of ~ 40 Msun located close to the apex of the Sickle. We investigate how the B-star MJ 218, the Sickle, and the clump are related. Our numerical simulations show that, in principle, a B-type star located near the edge of a clump can produce a crescent-shaped wind shock front, similar to the observed morphology. However, the observed proper motion of MJ 218 suggest that the star moves with high velocity (~ 100 km/s) through the ambient interstellar gas. We argue that the star is just about to graze along the surface of the clump, and the Sickle is a bow shock induced by the stellar wind, as the object moves supersonically through the density gradient in the envelope of the clump.

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Judith Ngoumou, Thomas Preibisch, Thorsten Ratzka, Andreas Burkert. 2013-04-24. The Mysterious Sickle Object in the Carina Nebula: A stellar wind induced bow shock grazing a clump?. https://doi.org/10.1088/0004-637x/769/2/139

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