Magnetic Fields Studies in the Next Decade: EAO Submillimetre Futures White Paper Series, 2019 (2001.05753v1)

Abstract: Magnetic fields are ubiquitous in our Universe, but remain poorly understood in many branches of astrophysics. A key tool for inferring astrophysical magnetic field properties is dust emission polarimetry. The James Clerk Maxwell Telescope (JCMT) is planning a new 850$\mu$m camera consisting of an array of 7272 paired Microwave Kinetic Inductance Detectors (MKIDs), which will inherently acquire linear polarization information. The camera will allow wide-area polarization mapping of dust emission at 14$^{\prime\prime}$-resolution, allowing magnetic field properties to be studied in a wide range of environments, including all stages of the star formation process, Asymptotic Giant Branch stellar envelopes and planetary nebula, external galaxies including starburst galaxies and analogues for the Milky Way, and the environments of active galactic nuclei (AGN). Time domain studies of AGN and protostellar polarization variability will also become practicable. Studies of the polarization properties of the interstellar medium will also allow detailed investigation of dust grain properties and physics. These investigations would benefit from a potential future upgrade adding 450$\mu$m capability to the camera, which would allow inference of spectral indices for polarized dust emission in a range of environments. The enhanced mapping speed and polarization capabilities of the new camera will transform the JCMT into a true submillimetre polarization survey instrument, offering the potential to revolutionize our understanding of magnetic fields in the cold Universe.

• The paper reveals that the new JCMT 850 μm camera with 7272 MKIDs boosts polarization mapping speed by at least 20-fold, revolutionizing magnetic field surveys.
• It employs enhanced dust emission polarimetry to unravel magnetic influences in star formation, stellar evolution, and active galactic nuclei.
• The study charts a clear path for future time-domain investigations, enabling detailed observation of dynamic magnetic field variations across cosmic scales.

Overview of "Magnetic Fields Studies in the Next Decade"

The paper "Magnetic Fields Studies in the Next Decade," authored by Ray S. Furuya and colleagues, delivers a comprehensive evaluation of impending advancements in the paper of astrophysical magnetic fields, driven principally by observational capabilities enhanced through dust emission polarimetry. Research into magnetic fields remains critically important as they play a fundamental role in shaping various astrophysical phenomena, yet their properties are not well comprehended across numerous domains of astrophysics.

Central to future advancements is the James Clerk Maxwell Telescope (JCMT)'s innovative 850 μm camera, which incorporates an array of 7272 Microwave Kinetic Inductance Detectors (MKIDs). This apparatus promises to inherently acquire linear polarization information, thus enabling expansive wide-area polarization mapping of dust emissions. Such mapping will enhance the ability to paper magnetic field attributes in several environments, from the intricacies of star formation processes to the formidable surroundings of active galactic nuclei (AGN).

Key Methodological Advances

The proposed JCMT camera is anticipated to bolster the mapping speed substantially, achieving at least a 20-fold increase in polarization mapping speed over the current POL-2 setup. This leap is expected to enable sweeping submillimeter polarimetric surveys and intricate observation of individual scientific targets. Such improvements herald a new paradigm in understanding magnetic fields within the universe's colder sectors.

Scientific Implications

Several domains stand to significantly benefit from these enhancements:

1. Star Formation and ISM: The empirical data produced will markedly boost comprehension of magnetic roles in star-forming molecular clouds. By resolving magnetic field configurations in these regions, researchers can better differentiate structures such as filamentary gas alignments, which are potentially influenced or even driven by magnetic forces.
2. Evolved Stars and Stellar Remnants: The data require an understanding of magnetic fields that heavily influence the dynamics of Asymptotic Giant Branch (AGB) stellar envelopes and planetary nebulae. These insights are invaluable for grasping the underlying mechanisms dictating stellar evolution and mass ejection processes, affecting formation rates and patterns across star environments.
3. Magnetic Fields in Galaxies and AGNs: The enhanced survey speed and sensitivity will allow a more detailed exploration of magnetic properties within external galaxies and centrally-hosted supermassive black holes. Dissecting such magnetic influences stands to provide significant insights into galaxy dynamics, starburst phenomena, and the complex physics surrounding AGNs.
4. Time-Domain Studies: The implications of temporal variation in magnetic fields, especially in rapidly evolving environments such as AGN jets and protostellar systems, will offer transformative insights into broader astrophysical processes. This capability opens new avenues for monitoring accretion-driven variability and its magnetic imprint.

Concluding Remarks

The proposed advances in instrumentation and methodology through the JCMT camera mark a pivotal step for the astrophysical community. By facilitating previously infeasible studies, the enhancements stand to revolutionize understandings of magnetic field roles across numerous cosmic phenomena. As such, this work adeptly lays the foundation for an empirical and theoretical renaissance in magnetic studies throughout the cosmic landscape, charting a course for substantial scientific inquiry and discovery. The continued refinement and implementation of these tools are crucial for unlocking the complex interplay of gravitational, turbulent, and magnetic forces shaping the universe.