Characterizing the Turbulent Properties of the Starless Molecular Cloud MBM 16

This is the authors' abstract. We don't add key points for this paper.

We investigate turbulent properties of the non-star-forming, translucent molecular cloud MBM 16 by applying the statistical technique of a two-dimensional spatial power spectrum (SPS) on the neutral hydrogen (H i ) observations obtained by the Galactic Arecibo L-Band Feed Array H i survey. The SPS, calculated over the range of spatial scales from 0.1 to 17 pc, is well represented with a single power-law function, with a slope ranging from −3.3 to −3.7 and being consistent over the velocity range of MBM 16 for a fixed velocity channel thickness. However, the slope varies significantly with the velocity slice thickness, suggesting that both velocity and density contribute to H i intensity fluctuations. By using this variation, we estimate the slope of three-dimensional density fluctuations in MBM 16 to be −3.7 ± 0.2. This is significantly steeper than what has been found for H i in the Milky Way plane, the Small Magellanic Cloud, or the Magellanic Bridge, suggesting that interstellar turbulence in MBM 16 is driven on scales >17 pc and that the lack of stellar feedback could be responsible for the steep power spectrum.