Magnetic Seismology of Interstellar Gas Clouds: Unveiling a Hidden Dimension

Abstract

Stars and planets are formed inside dense interstellar molecular clouds, by processes imprinted on the 3-dimensional (3D) morphology of the clouds. Determining the 3D structure of interstellar clouds remains challenging, due to projection effects and difficulties measuring their extent along the line of sight. We report the detection of normal vibrational modes in the isolated interstellar cloud Musca, allowing determination of the 3D physical dimensions of the cloud. Musca is found to be vibrating globally, with the characteristic modes of a sheet viewed edge-on, not a filament as previously supposed. We reconstruct the physical properties of Musca through 3D magnetohydrodynamic simulations, reproducing the observed normal modes and confirming a sheet-like morphology.

arXiv commentAccepted in Science, 24 pages, 8 figures. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science , (issue of May 11 2018), doi: 10.1126/science.aao1185

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