Mapping Disk Thickness of Neutral Hydrogen in the Magellanic Clouds

Abstract:

The spatial power spectrum (SPS) of the entire HI column density distribution of the Large Magellanic Cloud (LMC) can be fitted with two power-law functions, as shown in previous studies. We have applied the SPS analysis on sub-regions across the LMC and mapped the power-law slopes across this galaxy. In addition, we have mapped the physical scale of the break in the power spectrum, which corresponds to the thickness of the gas layer. We find significant spatial variation of the SPS slopes across the LMC, with significant steepening on large spatial scales in the outskirts of the galaxy. The HI disk is estimated to have a thickness of 200~ 300 pc in central regions and 100~ 200 pc along the outer edges. Similar analyses were performed on the Small Magellanic Cloud, showing more uniform turbulent properties across the galaxy. Understanding spatial variations of the disk thickness could illuminate turbulence …

Año de publicación:

2019

Keywords:

Fuente:

google