| dc.description.abstract | Herbig Ae/Be stars are young, pre-main-sequence stars that sample the transition in structure and evolution between
low- and high-mass stars, providing a key test of accretion processes in higher-mass stars. Few Herbig Ae/Be stars
have detected magnetic fields, calling into question whether the magnetospheric accretion paradigm developed for
low-mass stars can be scaled to higher masses. We present He i 10830 ˚A line profiles for 64 Herbig Ae/Be stars with a
magnetic field measurement in order to test magnetospheric accretion in the physical regime where its ecacy
remains
uncertain. Of the 5 stars with a magnetic field detection, 1 shows redshifted absorption, indicative of
infall, and 2 show blueshifted absorption, tracing mass outflow. The fraction of redshifted and blueshifted
absorption profiles in the non-magnetic Herbig Ae/Be stars is remarkably similar, suggesting that the stellar magnetic
field does not a↵ect gas kinematics traced by He i 10830 ˚A. Line profile morphology does not correlate with the
luminosity, rotation rate, mass accretion rate, or disk inclination. Only the detection of a magnetic field and a
nearly face-on disk inclination show a correlation (albeit for few sources). This provides further evidence
for weaker dipoles and more complex field topologies as stars develop a radiative envelope. The small number of
magnetic Herbig Ae/Be stars has already called into question whether magnetospheric accretion can be scaled to higher
masses; accretion signatures are not substantially di↵erent in magnetic Herbig Ae/Be stars, casting further doubt that
they accrete in the same manner as classical T Tauri stars. | en_GB |
