The Mysterious Sickle Object in the Carina Nebula: A Stellar Wind Induced Bow Shock Grazing a Clump?
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 submillimeter data from APEX/LABOCA as well as Herschel far-infrared maps, we discovered a dense, compact clump with a mass of ~40 M ☉ 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 suggests that the star moves with high velocity (~100 km s-1) 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.
The Astrophysical Journal
- Pub Date:
- June 2013
- infrared: ISM;
- shock waves;
- stars: individual: Trumpler 14 MJ 218;
- stars: winds;
- submillimeter: ISM;
- X-rays: stars;
- Astrophysics - Astrophysics of Galaxies
- Accepted for publication in ApJ(8 pages, 6 figures). A high quality preprint is available at: http://www.usm.uni-muenchen.de/people/preibisch/publications.html