scholarly journals Understanding the coexistence of spin-up and spin-down behaviours in long-period X-ray pulsars

2020 ◽  
Vol 492 (1) ◽  
pp. 762-769
Author(s):  
W Wang ◽  
H Tong
Keyword(s):  
Magnetic Field ◽  
Binary Systems ◽  
Accretion Rate ◽  
Constant Mass ◽  
X Ray ◽  
Spin Period ◽  
Long Period ◽  
Rotational Evolution ◽  
Order Of Magnitude ◽  
Field Decay

ABSTRACT Assuming wind-fed accretion magnetars in long-period X-ray pulsars, we calculated the rotational evolution of neutron stars. Our calculations considered the effects of magnetic field decay in magnetars. The results show that wind-fed accretion magnetars can evolve to long-period X-ray pulsars with a spin period much longer than 1000 s. The spin-down trend observed in 4U 2206+54-like sources is expected when young X-ray binary systems are on the way to their equilibrium period. Detailed calculations showed that the spin-down may be affected by accretion with outflows or accretion while spinning down. Due to magnetic field decay in magnetars, wind-fed accretion magnetars will have a decreasing equilibrium period for a constant mass accretion rate. For 2S 0114+65, the spin-up rate due to magnetic field decay is one order of magnitude smaller than observations. The spin-up rate of 2S 0114+65 may be attributed to the formation of a transient disc during wind accretion. The slowest X-ray pulsar AX J1910.7+0917 would be a link source between 4U 2206+54 and 2S 0114+65.

scholarly journals The Magnetic Field of the Intermediate Polar RE 0751+14

1996 ◽  
Vol 158 ◽  
pp. 183-183
Author(s):  
H. Väth
Keyword(s):  
Magnetic Field ◽  
White Dwarf ◽  
Accretion Rate ◽  
Shock Structure ◽  
Light Curves ◽  
X Rays ◽  
Strong Magnetic Fields ◽  
X Ray ◽  
Spin Period ◽  
The Magnetic Field

Piirola, Hakala & Coyne (1993) modeled the optical/IR light curve of RE 0751+14 assuming a uniform shock structure and neglecting the hard X-ray emission. In this paper, we model the light curves at optical/IR and hard X-ray wavelengths and include the effects of the shock structure.We base our model on accretion onto a white dwarf with a displaced magnetic dipole for a range of likely white dwarf masses. We find that the observed intensity variations of X-rays and in the I band over one spin period largely determine the position of the emission regions. Furthermore, the observed maximum X-ray flux constrains the specific accretion rate. We deduce that the magnetic field at the pole is likely to be in the range 9 .. .21 MG, which is consistent with the estimates of Piirola et al. (1993). It had been proposed previously that there must exist asynchronous rotators with sufficiently strong magnetic fields such that the binaries will evolve into AM Her binaries (Chanmugam & Ray 1984; King, Frank & Ritter 1985). With this deduced high magnetic field RE 0751+14 is the most likely example of such a system known to date.

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.

High-energy X-ray diffuse scattering

2009 ◽  
Vol 42 (3) ◽  
pp. 392-400 ◽  
Author(s):  
I. B. Ramsteiner ◽  
A. Schöps ◽  
H. Reichert ◽  
H. Dosch ◽  
V. Honkimäki ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
Diffuse Scattering ◽  
Binary Systems ◽  
High Energy ◽  
Absorption Length ◽  
Time Resolved ◽  
X Ray ◽  
Order Of Magnitude ◽  
Extinction Length ◽  
Scattering Volume

Diffuse X-ray scattering has been an important tool for understanding the atomic structure of binary systems for more than 50 years. The majority of studies have used laboratory-based sources providing 8 keV photons or synchrotron radiation with similar energies. Diffuse scattering is weak, with the scattering volume determined by the X-ray absorption length. In the case of 8 keV photons, this is not significantly different from the typical extinction length for Bragg scattering. If, however, one goes to energies of the order of 100 keV the scattering volume for the diffuse scattering increases up to three orders of magnitude while the extinction length increases by only one order of magnitude. This leads to a gain of two orders of magnitude in the relative intensity of the diffuse scattering compared with the Bragg peaks. This gain, combined with the possibility of recording the intensity from an entire plane in reciprocal space using a two-dimensional X-ray detector, permits time-resolved diffuse scattering studies in many systems. On the other hand, diffraction features that are usually neglected, such as multiple scattering, come into play. Four types of multiple scattering phenomena are discussed, and the manner in which they appear in high-energy diffraction experiments is considered.

scholarly journals Searching for a link between the magnetic nature and other observed properties of Herbig Ae/Be stars

2008 ◽  
Vol 4 (S259) ◽  
pp. 395-396 ◽  
Author(s):  
Swetlana Hubrig ◽  
C. Grady ◽  
M. Schöller ◽  
O. Schütz ◽  
B. Stelzer ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Survey ◽  
Accretion Rate ◽  
Be Stars ◽  
General Correlation ◽  
X Ray ◽  
Mass Accretion Rate ◽  
Debris Disk ◽  
Magnetic Nature

AbstractWe present the results of a new magnetic field survey of Herbig Ae/Be and A debris disk stars. They are used to determine whether magnetic field properties in these stars are correlated with the mass-accretion rate, disk inclinations, companion(s), Silicates, PAHs, or show a more general correlation with age and X-ray emission as expected for the decay of a remnant dynamo.

scholarly journals Recent Ginga Results on Galactic X-Ray Binaries

1992 ◽  
Vol 9 ◽  
pp. 211-215
Author(s):  
Y. Tanaka
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Related Problem ◽  
X Ray ◽  
Field Decay ◽  
X Ray Binaries ◽  
The Magnetic Field ◽  
Black Hole Candidates

AbstractBased on the recent Ginga results, following topics on X-ray binaries are briefly discussed: The cyclotron resonnance features observed from several X-ray pulsars, and related problem of the magnetic field decay. Search for millisec. pulsations from LMXRBs. Very bright transients which are suspected to be new black hole candidates, and an estimation of the number of such black hole sources in our galaxy.

Evidence for Magnetic Field Decay in the Slowest Known Be/X-ray Pulsars X Per and RX J0146.9+5121

2000 ◽  
Vol 175 ◽  
pp. 723-726
Author(s):  
X.-D. Li ◽  
Z.-R. Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
X Ray ◽  
Field Decay

AbstractWe argue that the slowest known Be/X-ray pulsars X Per and RX J0146.9+5121 currently possess relatively weak (≲ 1012 G) magnetic fields. Unless these pulsars were born rotating very slowly (initial periods longer than tens of seconds), in order to explain their long spin periods (~ 835 and ~ 1412 s, respectively), they must have had magnetic fields stronger than a few 1013 G; that is, their magnetic fields must have decayed.

scholarly journals Early neutron star evolution in high-mass X-ray binaries

2020 ◽  
Vol 494 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Wynn C G Ho ◽  
M J P Wijngaarden ◽  
Nils Andersson ◽  
Thomas M Tauris ◽  
F Haberl
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Thermal Emission ◽  
Equilibrium Phase ◽  
High Mass ◽  
X Ray ◽  
Spin Period ◽  
Long Duration ◽  
X Ray Binaries ◽  
The Magnetic Field

ABSTRACT The application of standard accretion theory to observations of X-ray binaries provides valuable insights into neutron star (NS) properties, such as their spin period and magnetic field. However, most studies concentrate on relatively old systems, where the NS is in its late propeller, accretor, or nearly spin equilibrium phase. Here, we use an analytic model from standard accretion theory to illustrate the evolution of high-mass X-ray binaries (HMXBs) early in their life. We show that a young NS is unlikely to be an accretor because of the long duration of ejector and propeller phases. We apply the model to the recently discovered ∼4000 yr old HMXB XMMU J051342.6−672412 and find that the system’s NS, with a tentative spin period of 4.4 s, cannot be in the accretor phase and has a magnetic field B > a few × 1013 G, which is comparable to the magnetic field of many older HMXBs and is much higher than the spin equilibrium inferred value of a few × 1011 G. The observed X-ray luminosity could be the result of thermal emission from a young cooling magnetic NS or a small amount of accretion that can occur in the propeller phase.

scholarly journals The Radius Estimation of Double Pulsar PSR J0737-3039A

2012 ◽  
Vol 8 (S290) ◽  
pp. 369-370 ◽  
Author(s):  
H. H. Zhao ◽  
L. M. Song
Keyword(s):  
Magnetic Field ◽  
Age Estimation ◽  
Accretion Rate ◽  
Millisecond Pulsar ◽  
Spin Period

AbstractWe investigate the radius of the recycled pulsar in double pulsar PSR J0737-3039. In the standard accretion spin-up model, the recycled pulsar spin up continues until arriving at a minimum spin period, or so-called “equilibrium period”, which is related to stellar magnetic field, accretion rate, mass and radius. If present spin period is much longer than that at birth, the spin-down age can give the realistic true age estimation for normal pulsar J0737-3039B. Base on the above conditions, we estimate the radius of millisecond pulsar (MSP) J0737-3039A by assuming its true age is same as the spin-down age of its companion J0737-3039B. We obtained that the radius of J0737-3039A ranges approximately from 5 to 27 km.

Period Clustering of the Anomalous X-Ray Pulsars and Magnetic Field Decay in Magnetars

2000 ◽  
Vol 529 (1) ◽  
pp. L29-L32 ◽  
Author(s):  
Monica Colpi ◽  
Ulrich Geppert ◽  
Dany Page
Keyword(s):  
Magnetic Field ◽  
X Ray ◽  
Field Decay

scholarly journals The surface and inner temperatures of magnetars

2012 ◽  
Vol 8 (S291) ◽  
pp. 386-388
Author(s):  
Z. F. Gao ◽  
N. Wang ◽  
Q. H. Peng
Keyword(s):  
Magnetic Field ◽  
Neutrino Emission ◽  
Effective Surface ◽  
X Ray ◽  
One To One ◽  
Field Decay ◽  
Neutrino Luminosity ◽  
The Magnetic Field

AbstractAssuming that the timescale of the magnetic field decay is approximately equal to that of the stellar cooling via neutrino emission, we obtain a one-to-one relationship between the effective surface thermal temperature and the inner temperature. The ratio of the effective neutrino luminosity to the effective X-ray luminosity decreases with decaying magnetic field.

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