Filamentary structures in planetary nebulae
2007 (English)In: Astrophysics and Space Science, ISSN 0004-640X, E-ISSN 1572-946X, Vol. 310, no 1-2, 65-72 p.Article in journal (Refereed) Published
We have studied small-scale, filamentary features in 14 planetary nebulae and found that some structures are recurrent and shaped like the letters V and Y, with the apex or stem pointing toward the central parts of the nebula. Two such filaments containing dust, one in NGC 3132 and one in NGC 7293, were investigated in more detail. The mass and density of the filaments were obtained from extinction measurements, and their physical properties were derived. We propose that the structures are confined by magnetic fields, and derive magnetic field strengths of about 10(-8) T, in line with earlier estimates. We also estimate the magnitude of the electric currents that we expect are generated in these dynamic systems. We propose a theory where the magnetic fields control the sculpting and evolution of small-scale filaments. This theory demonstrates how the substructures may form magnetized flux ropes that are twisted around each other, in the shape of double helices. Similar structures, and with similar origin, are found in many other astrophysical environments.
Place, publisher, year, edition, pages
2007. Vol. 310, no 1-2, 65-72 p.
planetary nebulae, filaments, double helix mechanism, NGC 3132, NGC 7293
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-37432DOI: 10.1007/s10509-007-9414-yISI: 000247635000010ScopusID: 2-s2.0-34347233451OAI: oai:DiVA.org:kth-37432DiVA: diva2:433951
QC 201108122011-08-122011-08-112011-08-12Bibliographically approved