Transition from ordered pinched to warped magnetic field on a 100 au
  scale in the Class 0 protostar B335
  We present our observational results of the 0.87 mm polarized dust emission
in the Class 0 protostar B335 obtained with the Atacama Large
Millimeter/submillimeter Array (ALMA) at a 0.2" (20 au) resolution. We compared
our data at 0.87 mm with those at 1.3 mm from the ALMA archive. The observed
polarization orientations at the two wavelengths are consistent within the
uncertainty, and the polarization percentages are systematically higher at 1.3
mm than 0.87 mm by a factor of ~1.7, suggesting that the polarized emission
originates from magnetically aligned dust grains. We inferred the magnetic
field orientations from the observed polarization orientations. We found that
the magnetic field changes from ordered and highly pinched to more complicated
and asymmetric structures within the inner 100 au scale of B335, and the
magnetic field connects to the center along the equatorial plane as well as
along the directions which are ~40-60 degrees from the equatorial plane. We
performed non-ideal MHD simulations of collapsing dense cores. We found that
similar magnetic field structures appear in our simulations of dense cores with
the magnetic field and rotational axis slightly misaligned by 15 degrees but
not in those with the aligned magnetic field and rotational axis. Our results
suggest that the midplane of the inner envelope within the inner 100 au scale
of B335 could be warped because of the misaligned magnetic field and rotational
axis, and the magnetic field could be dragged by the warped accretion flows.
