TY - JOUR
T1 - Polarized line emission from magnetized accretion flows
AU - Ferrario, Lilia
AU - Wickramasinghe, D. T.
AU - Schmidt, Gary
PY - 2002/4/11
Y1 - 2002/4/11
N2 - We construct models of polarized line emission from magnetized accretion flows and investigate how line circular polarization can be used to infer the dynamics and the physics of the field-channelled flow in AM Herculis systems. We show that the line-polarization characteristics depend strongly on field and velocity gradients in the gas. We identify two regions of the flow which can contribute to the polarized line emission. The first is the funnelled flow out of the orbital plane along undistorted field lines. The second is the flow in the transition region closer to the orbital plane where the field lines are distorted, and the fluid motion changes from ballistic to corotation with the white dwarf. We argue that depending on field orientation and viewing aspect one or the other could dominate. In the high-inclination system AR UMa, the polarized line emission is dominated by field-channelled flow in the transition region. In contrast, in the low-inclination system V884 Her, the polarized line emission appears to be dominated by funnel flow along undistorted field lines.
AB - We construct models of polarized line emission from magnetized accretion flows and investigate how line circular polarization can be used to infer the dynamics and the physics of the field-channelled flow in AM Herculis systems. We show that the line-polarization characteristics depend strongly on field and velocity gradients in the gas. We identify two regions of the flow which can contribute to the polarized line emission. The first is the funnelled flow out of the orbital plane along undistorted field lines. The second is the flow in the transition region closer to the orbital plane where the field lines are distorted, and the fluid motion changes from ballistic to corotation with the white dwarf. We argue that depending on field orientation and viewing aspect one or the other could dominate. In the high-inclination system AR UMa, the polarized line emission is dominated by field-channelled flow in the transition region. In contrast, in the low-inclination system V884 Her, the polarized line emission appears to be dominated by funnel flow along undistorted field lines.
KW - Binaries: general
KW - Novae, cataclysmic variables
KW - Stars: individual: AR UMa
KW - Stars: individual: V884 Her
KW - Stars: magnetic fields
KW - White dwarfs
UR - http://www.scopus.com/inward/record.url?scp=0042191718&partnerID=8YFLogxK
U2 - 10.1046/j.1365-8711.2002.05224.x
DO - 10.1046/j.1365-8711.2002.05224.x
M3 - Article
SN - 0035-8711
VL - 331
SP - 736
EP - 744
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -