Abstract
We have succeeded in obtaining magnetized equilibrium states with differential rotation and differential toroidal magnetic fields. If an internal toroidal field of a protoneutron star is wound up from the initial poloidal magnetic field by differential rotation, the distribution of the toroidal magnetic field is determined by the profile of this differential rotation. However, the distributions of the toroidal fields in all previous magnetized equilibrium studies do not represent the magnetic winding by the differential rotation of the star. In this paper, we investigate a formulation of a differential toroidal magnetic field that represents the magnetic field wound up by differential rotation. We have developed two functional forms of differential toroidal fields which correspond to a v-constant and a j-constant field in analogy to differential rotations. As the degree of the differential becomes very high, the toroidal magnetic field becomes highly localized and concentrated near the rotational axis. Such a differential toroidal magnetic field would suppress the low-T/|W| instability more efficiently even if the total magnetic field energy is much smaller than that of a non-differential toroidal magnetic field.
| Original language | English |
|---|---|
| Pages (from-to) | 4016-s4024 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 450 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2015 Apr 24 |
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Keywords
- Stars: magnetic field
- Stars: neutron
- Stars: rotation
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Magnetized stars with differential rotation and a differential toroidal field. / Fujisawa, Kotaro.
In: Monthly Notices of the Royal Astronomical Society, Vol. 450, No. 4, 24.04.2015, p. 4016-s4024.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Magnetized stars with differential rotation and a differential toroidal field
AU - Fujisawa, Kotaro
PY - 2015/4/24
Y1 - 2015/4/24
N2 - We have succeeded in obtaining magnetized equilibrium states with differential rotation and differential toroidal magnetic fields. If an internal toroidal field of a protoneutron star is wound up from the initial poloidal magnetic field by differential rotation, the distribution of the toroidal magnetic field is determined by the profile of this differential rotation. However, the distributions of the toroidal fields in all previous magnetized equilibrium studies do not represent the magnetic winding by the differential rotation of the star. In this paper, we investigate a formulation of a differential toroidal magnetic field that represents the magnetic field wound up by differential rotation. We have developed two functional forms of differential toroidal fields which correspond to a v-constant and a j-constant field in analogy to differential rotations. As the degree of the differential becomes very high, the toroidal magnetic field becomes highly localized and concentrated near the rotational axis. Such a differential toroidal magnetic field would suppress the low-T/|W| instability more efficiently even if the total magnetic field energy is much smaller than that of a non-differential toroidal magnetic field.
AB - We have succeeded in obtaining magnetized equilibrium states with differential rotation and differential toroidal magnetic fields. If an internal toroidal field of a protoneutron star is wound up from the initial poloidal magnetic field by differential rotation, the distribution of the toroidal magnetic field is determined by the profile of this differential rotation. However, the distributions of the toroidal fields in all previous magnetized equilibrium studies do not represent the magnetic winding by the differential rotation of the star. In this paper, we investigate a formulation of a differential toroidal magnetic field that represents the magnetic field wound up by differential rotation. We have developed two functional forms of differential toroidal fields which correspond to a v-constant and a j-constant field in analogy to differential rotations. As the degree of the differential becomes very high, the toroidal magnetic field becomes highly localized and concentrated near the rotational axis. Such a differential toroidal magnetic field would suppress the low-T/|W| instability more efficiently even if the total magnetic field energy is much smaller than that of a non-differential toroidal magnetic field.
KW - Stars: magnetic field
KW - Stars: neutron
KW - Stars: rotation
UR - http://www.scopus.com/inward/record.url?scp=84938153917&partnerID=8YFLogxK
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U2 - 10.1093/mnras/stv905
DO - 10.1093/mnras/stv905
M3 - Article
VL - 450
SP - 4016-s4024
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -