Interstellar HI: Filaments and threads
Abstract
A very long and nearly straight HI filament at about -60 km s-1 in the southern galactic hemisphere, seen nearly normal to the line-of-sight and well separated from low velocity gas, has been studied in several ways in order to understand its physics, structure, and morphology. Gaussian analysis of 1800 profiles show an underlying HI component, which is at least 15 deg. long and about 1 deg. wide, has a typical line width of 21 km/s. At a distance of 100 pc it would be confined by a magnetic field of 18 μG. Examination of 140 declination-velocity cross-sections revealed evidence for narrow, elongated features (threads) unresolved in width within the boundaries of the filament. These cooler components have an average density of 29 cu.cm. and may be confined by a magnetic field of 5 μG. These results, taken together, suggest that interstellar HI filaments may have magnetic substructure.
- Publication:
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American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23311107V