Mapping Spatial Variations of HI Turbulent Properties in the Small and Large Magellanic Cloud

Abstract

We developed methods for mapping spatial variations of the spatial power spectrum (SPS) and structure function (SF) slopes, with a goal of connecting neutral hydrogen (HI) statistical properties with the turbulent drivers. The new methods were applied on the HI observations of the Small and Large Magellanic Clouds (SMC and LMC). In the case of the SMC, we find highly uniform turbulent properties of HI, with no evidence for local enhancements of turbulence due to stellar feedback. Such properties could be caused by a significant turbulent driving on large-scales. Alternatively, a significant line-of-sight depth of the SMC could be masking out localized regions with a steeper SPS slope caused by stellar feedback. In contrast to the SMC, the LMC HI shows a large diversity in terms of its turbulent properties. Across most of the LMC, the small-scale SPS slope is steeper than the large-scale slope due to the presence of the HI disk. On small spatial scales, we find several areas of localized steepening of the SPS slope around major HII regions, with the 30 Doradus region being the most prominent. This is in agreement with predictions from numerical simulations which suggest steepening of the SPS slope due to stellar feedback eroding and destroying interstellar clouds. We also find localized steepening of the large-scale SPS slope in the outskirts of the LMC. This is likely caused by the flaring of the HI disk, or alternatively ram-pressure stripping of the LMC disk due to the interactions with the surrounding halo gas.

17 pages, 14 figures, accepted to the ApJ

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Cited by in corpus (8)

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• The Dependence of the Hierarchical Distribution of Star Clusters on Galactic Environment
• Spatial Power Spectra of Dust across the Local Group: No Constraint on Disc Scale Height
• Evidence of large scale energy cascade in the spiral galaxy NGC 5236
• The VMC survey -- XLVII. Turbulence-Controlled Hierarchical Star Formation in the Large Magellanic Cloud
• A Search for correlations between turbulence and star formation in THINGS galaxies
• Testing massive star evolution, star-formation history, and feedback at low metallicity: Photometric analysis of OB stars in the SMC Wing