tokens: of the relatively isolated star formation. External compression of the core (e.g., Frau et al. 2015 for the possibility of the cloud–cloud collision in the Pipe Nebula) may also initiate the star formation in the core. Rotation of the core does not affect its stability. The rotational kinetic energy of the core is only approximately 1% of the gravitational energy (Aguti et al. 2007 ). Uncertainty arising from the use of the plane-of-sky field component increases the importance of magnetic support. The magnetic field close to a pole-on geometry leads to the condition (subcritical). Therefore, 3D modeling of the polarization structure is desirable in order to determine the line-of-sight inclination angle of the core’s magnetic axis. The formation of a nearly critical core accompanied by a distorted magnetic field is an open problem. Consideration of the interplay among gravity, thermal pressure, and turbulence is necessary in order to understand the formation and evolution mechanism of FeSt 1–457. Quasi-static contraction under the support of a magnetic field (Shu 1977 ) requires a strong magnetic field, and this is not the case for FeSt 1–457 (, magnetically supercritical). In the other extreme, supersonic turbulence can produce cores that collapse dynamically and that are accompanied by highly supersonic infalling motion (e.g., Mac Low Klessen 2004 ). This is also not the case for FeSt 1–457 because nearly critical stability was shown in the present study and radio observations (Kandori et al. 2005 ; Aguti et al. 2007 ) showed quiescent kinematic gas motion in the core. Core formation between the two extreme models may account for the formation of FeSt 1–457 (e.g., Nakamura Li 2005 ; Basu et al. 2009a , 2009b ). Further theoretical studies on such a case are desirable. The relative importance of the magnetic field for the support of the core is investigated through the ratios of the thermal and turbulent energy to the magnetic energy, which are expressed as and , where , , and denote the isothermal sound speed at 9.5 K, the turbulent velocity dispersion, and the Alfvén velocity, respectively. The numerical coefficients differ in the equation depending on whether the velocity dispersion is in 1D or 3D. These ratios were found to be and . FeSt 1–457 is dominated by a static magnetic field and thermal support with a small contribution from turbulence. Turbulence could be an important parameter in the formation and development of the core, although it seems to have already mostly dissipated at the observed stage in the prestellar evolution. Therefore, a static magnetic field, the predominant component of anisotropic pressure in the core, should act as a key parameter controlling the star formation process in FeSt 1–457. Figure 8 shows the relationships among the orientations (position angles) of the axis of the elongation of the core (), the rotation axis (, Aguti et al. 2007 ), and the magnetic field axis (). Note that the elongation of the
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