1. A rotating helical filament in the L1251 dark cloud
- Author
-
Christian Henkel, S. A. Levshakov, and Dieter Reimers
- Subjects
Physics ,010308 nuclear & particles physics ,Magnetic Reynolds number ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Magnetic field ,Rossby number ,Protein filament ,Sinistral and dextral ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Spectral resolution ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Line (formation) ,Dynamo - Abstract
(Abridged) Aims. We derive the physical properties of a filament discovered in the dark cometary-shaped cloud L1251. Methods. Mapping observations in the NH3(1,1) and (2,2) inversion lines, encompassing 300 positions toward L1251, were performed with the Effelsberg 100-m telescope at a spatial resolution of 40 arcsec and a spectral resolution of 0.045 km/s. Results. The filament L1251A consists of three condensations (alpha, beta, and gamma) of elongated morphology, which are combined in a long and narrow structure covering a 38 arcmin by 3 arcmin angular range. The opposite chirality (dextral and sinistral) of the alpha+beta and gamma condensations indicates magnetic field helicities of two types, negative and positive, which were most probably caused by dynamo mechanisms. We estimated the magnetic Reynolds number Rm > 600 and the Rossby number R < 1, which means that dynamo action is important., 21 pages, 10 figures, 1 table. Accepted for publication in A&A
- Published
- 2016