Quantifying the anisotropic density structure of the Central Molecular Zone -- a 2D correlation function approach

Abstract

The Central Molecular Zone (CMZ) is a ring-like structure sitting at the center of the Milky Way. Using the 870 $\mu$m continuum map from the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL), we study the anisotropy of the density structure of the gas in the Central Molecular Zone (CMZ) using the 2D correlation function. To quantify the spatial anisotropy, we define the critical angle ${\theta }_{\mathrm{half}}$, as well as the anisotropy parameter $A\equiv \frac{\pi }{4{\theta }_{\mathrm{half}}}-1$. We find that the density structure is strongly anisotropic at the large scale (~ 100 pc), and the degree of spatial anisotropy decreases with the decreasing scale. At the scale of ~ 10 pc, the structure is still mildly anisotropic. In our analyses, we provide a quantitative description of the anisotropic density structure of gas in the CMZ, and the formalism can be applied to different regions to study their differences.

arXiv comment8 pages,12 figures, accepted by RAA

References in corpus (19)

• A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
• Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way
• ATLASGAL - The APEX Telescope Large Area Survey of the Galaxy at 870 microns
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• The Nuclear Bulge of the Galaxy. III. Large-Scale Physical Characteristics of Stars and Interstellar Matter
• Variations in the Galactic star formation rate and density thresholds for star formation
• Dense gas in the Galactic central molecular zone is warm and heated by turbulence
• Large-scale filaments associated with Milky Way spiral arms
• The Bones of the Milky Way
• The interplay between a galactic bar and a supermassive black hole: nuclear fueling in a sub-parsec resolution galaxy simulation
• The data reduction pipeline for the Hi-GAL survey
• Spurs and feathering in spiral galaxies
• ATLASGAL -- A Galaxy-wide sample of dense filamentary structures
• The Galactic Center Cloud G0.253+0.016: A Massive Dense Cloud with low Star Formation Potential
• The dynamical evolution of molecular clouds near the Galactic Centre - II. Spatial structure and kinematics of simulated clouds
• Seeding the Galactic Centre gas stream: gravitational instabilities set the initial conditions for the formation of protocluster clouds
• A 500 pc filamentary gas wisp in the disk of the Milky Way
• On the physical mechanisms governing the cloud lifecycle in the Central Molecular Zone of the Milky Way
• A mean density of $112M_{\odot }\mathrm{p}{\mathrm{c}}^{-3}$ for Central Molecular Zone clumps -- Evidences for shear-enabled pressure equilibrium in the Galactic Center