Magnetic fields are ubiquitous throughout our Milky Way Galaxy and they play a crucial role in all dynamics of interstellar medium. Have you ever wondered how the Solar-type stars form out of the magnetized molecular clouds? What is the role of magnetic fields at various scales and densities of molecular clouds? What factors could change the morphology of magnetic fields in low-mass dense cores?

A new study led by Dr. Eswaraiah Chakali from Prof. Di Li's research group in National Astronomical Observatories of Chinese Academy of Sciences (NAOC), has revealed "diverse magnetic field morphologies in the Solar-type star forming cores in Taurus B213 region".

This study was published by The Astrophysical Journal Letters on May 10.

This work has used high resolution and sensitive 850 micron dust emission polarization data acquired from James Clerk Maxwell Telescope (JCMT) using camera SCUBA-2 along with polarimeter POL-2. The observations were conducted as a part of international large program called B-fields In STar-forming Region Observations (BISTRO).

"Although formed out of the same filamentary cloud, Taurus/B213, only one out of three dense cores remembers the relatively uniform large-scale magnetic field threading the parental cloud," said Dr Eswaraiah Chakali, the leading author of this study.

This is in contrast to the expectation based on the theory of magnetic field regulated star formation. If large scale magnetic field dominates throughout cloud accumulation, core collapse, and the star formation within, the mean position angle of the magnetic field should be similar across various spatial scales. Further analysis of the gas velocity gradient reveal that the kinematics due to gas accretion flows onto the parental filament could have altered the magnetic field configuration.

"Therefore, even in the presence of substantial magnetic flux, the local physical conditions can significantly affect the magnetic field morphology and their role in star formation," said Prof. Di Li of NAOC, the co-corresponding author.

Prof. Keping Qiu of Nanjing University, the co-PI of the BISTRO project and a coauthor, commented "our current observations represent one of the deepest sub-millimeter polarimetry images ever taken using the single dish telescope toward a Galactic region".

Prof. Di Li also highlighted that "further, more comprehensive analyses, in combination with Planck data and stellar polarimetry, poise to shed critical lights into the evolution of magnetic fields in this stereotypical low mass star forming region".

Figure 1: Core-scale magnetic fields (red segments) inferred using high-resolution and sensitive dust emission polarization observations using JCMT. The Solar-type star forming cores fragmented out of B213 filament are shown. (Credit: Chakali, Eswaraiah, et al. 2021)

Figure 2: Large-scale, uniform magnetic field morphology of Taurus/B213 region, inferred based on multi-wavelength polarization data. The extent of Figure 1 is marked with a white box. (Credit: Chakali, Eswaraiah, et al. 2021)   

The paper can be accessed at https://iopscience.iop.org/article/10.3847/2041-8213/abeb1c