scholarly journals Magnetic field amplification in proto-neutron stars

2007 ◽  
Vol 479 (1) ◽  
pp. 167-176 ◽  
Author(s):  
L. Naso ◽  
L. Rezzolla ◽  
A. Bonanno ◽  
L. Paternò
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Field Amplification

scholarly journals Magnetic field amplification in newly-born neutron stars

1996 ◽  
Vol 160 ◽  
pp. 435-436
Author(s):  
H.-J. Wiebicke ◽  
U. Geppert
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Gravitational Collapse ◽  
Dipole Field ◽  
Numerical Calculations ◽  
Selection Effects ◽  
Thermoelectric Effects ◽  
Field Amplification ◽  
Seed Field ◽  
Flux Conservation

AbstractWe present a scenario of magnetic field (MF) evolution of newly-born neutron stars (NSs). Numerical calculations show that in the hot phase of young NSs the MF can be amplified by thermoelectric effects, starting from a moderately strong seed-field. Therefore, there is no need to assume a 1012G dipole field immediately after the gravitational collapse of the supernova (SN) event. The widely accepted scenario for such a field to be produced by flux conservation during the collapse is critically discussed. Instead, it can be generated by amplification and selection effects in the first 104yrs, and by the subsequent fast ohmic decay of higher multipole components, when the NS cools down.

scholarly journals Galactic and Metagalactic Magnetic Fields

1972 ◽  
Vol 44 ◽  
pp. 520-525
Author(s):  
K. Brecher
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Galactic Nuclei ◽  
Direct Result ◽  
Field Amplification ◽  
Recent Origin ◽  
Intergalactic Magnetic Field ◽  
Rotating Objects

All of the possible sources of primeval magnetic fields are examined and found to be inadequate to account for the observed galactic B-fields (if the magnetic fields in galaxies are the direct result of the condensation of a magnetized metagalactic medium). Field amplification in dense rotating objects (perhaps neutron stars or galactic nuclei) may be responsible for the bulk of such fields. Most of the (hypothetical) intergalactic B-field then originates in galaxies and is dragged along with the cosmic rays escaping from them. Limits are placed on the value of any present intergalactic magnetic field of either primordial or ‘recent’ origin.

scholarly journals SGRs and AXPs: Evidence for Delayed Amplification of Magnetic Field after Neutron Star Formation?

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Denis Leahy ◽  
Rachid Ouyed
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Birth Rate ◽  
Massive Stars ◽  
Robust Estimator ◽  
High Magnetic Fields ◽  
Field Amplification ◽  
Kolmogorov Smirnov

We present new analysis of the birth rate of AXPs and SGRS and their associated SNRs. Using Kolmogorov-Smirnov statistics together with parametric fits based on a robust estimator, we find a birth rate of ∼1/(1000 years) for AXPs/SGRs and their associated SNRs. These high rates suggest that all massive stars (greater than ∼(23–32)M⊙) give rise to remnants with magnetar-like fields. Observations indicate a limited fraction of high magnetic fields in these progenitors; thus our study is suggestive of magnetic field amplification. Dynamo mechanisms during the birth of the neutron stars require spin rates much faster than either observations or theory indicate. We propose that massive stars produce neutron stars with normal (∼1012 G) magnetic fields, which are then amplified to1014-1015 G after a delay of hundreds of years. The amplification is speculated to be a consequence of color ferromagnetism and to occur with a delay after the neutron star core reaches quark deconfinement density (i.e., the quark-nova scenario). The delayed amplification allows one to interpret simultaneously the high birth rate and high magnetic fields of AXPs/SGRs and their link to massive stars.

scholarly journals A New View on Young Pulsars in Supernova Remnants: Slow, Radio-quiet & X-ray Bright

2000 ◽  
Vol 177 ◽  
pp. 699-702 ◽  
Author(s):  
E. V. Gotthelf ◽  
G. Vasisht
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Simple Explanation ◽  
Crab Pulsar ◽  
Radio Pulsars ◽  
Substantial Fraction ◽  
Subsequent Evolution ◽  
X Ray ◽  
Field Decay

AbstractWe propose a simple explanation for the apparent dearth of radio pulsars associated with young supernova remnants (SNRs). Recent X-ray observations of young remnants have revealed slowly rotating (P∼ 10s) central pulsars with pulsed emission above 2 keV, lacking in detectable radio emission. Some of these objects apparently have enormous magnetic fields, evolving in a manner distinct from the Crab pulsar. We argue that these X-ray pulsars can account for a substantial fraction of the long sought after neutron stars in SNRs and that Crab-like pulsars are perhaps the rarer, but more highly visible example of these stellar embers. Magnetic field decay likely accounts for their high X-ray luminosity, which cannot be explained as rotational energy loss, as for the Crab-like pulsars. We suggest that the natal magnetic field strength of these objects control their subsequent evolution. There are currently almost a dozen slow X-ray pulsars associated with young SNRs. Remarkably, these objects, taken together, represent at least half of the confirmed pulsars in supernova remnants. This being the case, these pulsars must be the progenitors of a vast population of previously unrecognized neutron stars.

Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars

2008 ◽  
Vol 32 (2) ◽  
pp. 108-111 ◽  
Author(s):  
Liu Jing-Jing ◽  
Luo Zhi-Quan
Keyword(s):  
Magnetic Field ◽  
Energy Loss ◽  
Neutron Stars ◽  
Electron Capture ◽  
Neutrino Energy

MAGNETIC FIELD AMPLIFICATION BY RELATIVISTIC SHOCKS IN AN INHOMOGENEOUS MEDIUM

2012 ◽  
Vol 08 ◽  
pp. 364-367
Author(s):  
YOSUKE MIZUNO ◽  
MARTIN POHL ◽  
JACEK NIEMIEC ◽  
BING ZHANG ◽  
KEN-ICHI NISHIKAWA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Inhomogeneous Medium ◽  
Magnetic Energy ◽  
Small Scale ◽  
Two Dimensional ◽  
Filamentary Structure ◽  
Field Amplification ◽  
Relativistic Shocks ◽  
Field Lines ◽  
Magnetohydrodynamic Simulations

We perform two-dimensional relativistic magnetohydrodynamic simulations of a mildly relativistic shock propagating through an inhomogeneous medium. We show that the postshock region becomes turbulent owing to preshock density inhomogeneity, and the magnetic field is strongly amplified due to the stretching and folding of field lines in the turbulent velocity field. The amplified magnetic field evolves into a filamentary structure in two-dimensional simulations. The magnetic energy spectrum is flatter than the Kolmogorov spectrum and indicates that the so-called small-scale dynamo is occurring in the postshock region. We also find that the amplitude of magnetic-field amplification depends on the direction of the mean preshock magnetic field.

scholarly journals Evidence for Heating of Neutron Stars by Magnetic-Field Decay

2007 ◽  
Vol 98 (7) ◽  
Author(s):  
José A. Pons ◽  
Bennett Link ◽  
Juan A. Miralles ◽  
Ulrich Geppert
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Field Decay

scholarly journals Magnetic field amplification in cold dark matter anisotropic collapse

2003 ◽  
Vol 338 (3) ◽  
pp. 785-789 ◽  
Author(s):  
Marco Bruni ◽  
Roy Maartens ◽  
Christos G. Tsagas
Keyword(s):  
Magnetic Field ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Field Amplification
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