Striations in the Taurus molecular cloud: Kelvin–Helmholtz instability or MHD waves?
| Autor: | Edith Falgarone, U. A. Yildiz, Jorge L. Pineda, R. L. Snell, Paul F. Goldsmith, Mark H. Heyer |
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| Přispěvatelé: | Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL) |
| Rok vydání: | 2016 |
| Předmět: |
010504 meteorology & atmospheric sciences
Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Instability 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics ComputingMilieux_MISCELLANEOUS Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Line (formation) [PHYS]Physics [physics] Physics Filling factor Molecular cloud Astronomy Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Magnetic field Interstellar medium 13. Climate action Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Magnetohydrodynamics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Striation |
| Zdroj: | Monthly Notices of the Royal Astronomical Society Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2016, 461 (4), pp.3918-3926. ⟨10.1093/mnras/stw1567⟩ Monthly Notices of the Royal Astronomical Society, 2016, 461 (4), pp.3918-3926. ⟨10.1093/mnras/stw1567⟩ |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | The origin of striations aligned along the local magnetic field direction in the translucent envelope of the Taurus molecular cloud is examined with new observations of 12CO and 13CO J=2-1 emission obtained with the 10~m submillimeter telescope of the Arizona Radio Observatory. These data identify a periodic pattern of excess blue and redshifted emission that is responsible for the striations. For both 12CO and 13CO, spatial variations of the J=2-1 to J=1-0 line ratio are small and are not spatially correlated with the striation locations. A medium comprised of unresolved CO emitting substructures (cells) with a beam area filling factor less than unity at any velocity is required to explain the average line ratios and brightness temperatures. We propose that the striations result from the modulation of velocities and the beam filling factor of the cells as a result of either the Kelvin-Helmholtz instability or magnetosonic waves propagating through the envelope of the Taurus molecular cloud. Both processes are likely common features in molecular clouds that are sub-Alfvenic and may explain low column density, cirrus-like features similarly aligned with the magnetic field observed throughout the interstellar medium in far-infrared surveys of dust emission. 11 pages, 4 figures. Accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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