Multi-scale Magnetic Fields in the Central Molecular Zone: Inference from the Gradient Technique

Abstract

The central molecular zone (CMZ) plays an essential role in regulating the nuclear ecosystem of our Galaxy. To get an insight into the magnetic fields of the CMZ, we employ the Gradient Technique (GT), which is rooted in the anisotropy of magnetohydrodynamic turbulence. Our analysis is based on the data of multiple wavelengths, including molecular emission lines, radio 1.4 GHz continuum image, and Herschel 70 $\mu$m image, as well as ionized [Ne II] and Paschen-alpha emissions. The results are compared with the observations of Planck 353 GHz and High-resolution Airborne Wideband Camera Plus (HWAC+) 53 $\mu$m polarized dust emissions. We map the orientation of the magnetic field at multiple wavelengths across the central molecular zone, including close-ups of the Radio Arc and Sagittarius A West regions, on multi scales from $\sim$ 0.1 pc to 10 pc. The magnetic fields towards the central molecular zone traced by GT are globally compatible with the polarization measurements, accounting for the contribution from the galactic foreground and background. This correspondence suggests that the magnetic field and turbulence are dynamically crucial in the galactic center. We find that the magnetic fields associated with the Arched filaments and the thermal components of the Radio Arc are in good agreement with the HAWC+ polarization. Our measurement towards the non-thermal Radio Arc reveals the poloidal magnetic field components in the galactic center. For Sagittarius A West region, we find a great agreement between the GT measurement using [Ne II] emission and HWAC+ 53 $\mu$m observation. We use GT to predict the magnetic fields associated with ionized Paschen-alpha gas down to scales of 0.1 pc.

15 pages, 13 figures, accepted for publication in MNRAS

References in corpus (13)

• Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust
• Tracing Magnetic Fields with Aligned Grains
• Velocity Gradients as a Tracer for Magnetic Fields
• Subsonic Mechanical Alignment of Irregular Grains
• Tracing interstellar magnetic field using velocity gradient technique: Application to Atomic Hydrogen data
• Magnetic Field Morphology in Interstellar Clouds with the Velocity Gradient Technique
• Main-sequence stars masquerading as Young Stellar Objects in the central molecular zone
• Magnetic field near the central region of the Galaxy: Rotation measure of extragalactic sources
• Extragalactic sources towards the central region of the Galaxy
• Revealing Gravitational Collapse in Serpens G3-G6 Molecular Cloud using Velocity Gradients
• Far-infrared polarimetry from the Stratospheric Observatory for Infrared Astronomy
• ALMA Detection of Extreme Blue-Shifted Ionized Gas Within 0.2 pc of Sgr A* from -480 to -300 km/s
• Intermittency of Fast MHD Modes and Regions of Anomalous Gradient Orientation in Low-beta Plasmas

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• Probing Three-Dimensional Magnetic Fields: I -- Polarized Dust Emission
• Characterizing three-dimensional magnetic field, turbulence, and self-gravity in the star-forming region L1688
• Parallel and Perpendicular Alignments of Velocity Gradient and Magnetic Field observed in the Molecular Clouds L1478 and L1482