Removal of the difference between characteristic and real age in the magnetar model from the analysis of spectral properties of AXPs, SGRs and DRQNSs

Guseinov, OH
Taskin, O
Yazgan, E
Tagieva, S
We put together many observational data of SGRs and AXPs and analyze them with the main purpose to remove contradiction between the real age of these objects and their characteristic times of period change. This work indicates that SGRs and AXPs are neutron stars with magnetic fields up to similar to3 x 10(14) G at birth, which is less than the possible value in the existing magnetar model. These neutron stars undergo starquakes and reconnection of magnetic field occurs from time to time. As a result of these processes plasma is ejected from the NS and propeller mechanism starts to work. Due to the propeller effect P increases and tau decreases. Indeed, high P values are observed in SGRs and in half of the AXPs. Then, for a long time NS looses its activity, its P decreases, tau increases and rapid cooling begins. Each NS stage (AXP, SGR, dim) may occur once or several times until the spin period of the neutron star becomes P > 10-12 s. At the transition period to the SCR and AXP stages, the magnetic field component perpendicular to the rotation axis may increase up to 2-3 times. Observational data and mainly the data of AXP1E1048-5937 and DRQNS RX J1308.8+2127 support this idea.


Do young neutron stars which show themselves as AXPs and SGRs accrete?
Tagieva, SO; Yazgan, E; Ankay, A (World Scientific Pub Co Pte Lt, 2003-05-01)
We examined the fall-back disk models, and in general accretion, proposed to explain the properties of AXPs and SGRs. We checked the possibility of some gas remaining around the neutron star after a supernova explosion. We also compared AXPs and SGRs with the X-ray pulsars in X-ray binaries. We conclude that the existing models of accretion from a fall-back disk are insufficient to explain the nature of AXPs and SGRs.
On period and burst histories of AXPs and SGRs and the possible evolution of these objects on the P-P diagram
Guseinov, OH; Yazgan, EFE; Ankay, A; Tagieva, S (World Scientific Pub Co Pte Lt, 2003-01-01)
In this paper, timing data for anomalous X-ray pulsars and soft gamma repeaters are compiled. Timing properties of these objects are investigated. The effect of bursts of soft gamma repeaters on their period history is investigated. The P-P diagram for pulsars, X-ray binaries, anomalous X-ray pulsars, soft gamma repeaters and dim radio quiet neutron stars is constructed. The possible evolutionary tracks for anomalous X-ray pulsars, soft gamma repeaters and dim radio quiet neutron stars are examined.
Modelling the oscillating star V1162 Ori
Civelek, R; Kiziloglu, N; Kirbiyik, H (EDP Sciences, 2003-12-01)
Evolutionary stellar models of V1162 Ori, with the latest observations of a multiperiodic delta Scuti star, have been calculated theoretically and compared with the observations. Theoretical models representative of the star indicate that it is at an advanced stage of its main-sequence evolution. Calculations have been made for two different masses, 1.80 and 1.82 M-., at different rotational speeds. Rotation was treated as a perturbation and only the first-order effect was considered. The evolutionary model...
Investigations of pulsational properties and evolution of propagation diagram in some delta Scuti star models
Kiziloglu, N; Kirbiyik, H; Civelek, R (World Scientific Pub Co Pte Lt, 2003-07-01)
An investigation on the subject of evolution of propagation diagrams and obtaining the theoretical frequency spectrum of some delta Scuti star models with masses around 2 M-circle dot has been presented. The variations of some eigenfunctions throughout the star, the variation of omega(2) with logT(e) and the distribution of nodes of eigenfunctions of some modes along with the evolution of the star have been plotted and examined. For the models at the ZAMS phase, pure acoustic modes in the outer stellar laye...
A photometric-spectroscopic analysis and the evolutionary status of the Algol-type binary U Coronae Borealis
Yerli, Sinan Kaan; Zola, S; Smith, RC; Tovmassian, G (Oxford University Press (OUP), 2003-07-11)
The prime purposes of this study are to obtain reliable orbital parameters for the Algol-type binary U Coronae Borealis (U CrB) and to explain the evolutionary status of this system. All observations of the primary star's radial velocity are consistent with the value K(1) = 58.6 +/- 2.0 km s(-1). Measurements of the radial velocity of the secondary component give K(2) = 185.2 +/- 5.0 km s(-1). Using the photometrically determined inclination of 78.7 +/- 0.3, the masses of the two stars are therefore deduced...
Citation Formats
O. Guseinov, O. Taskin, E. Yazgan, and S. Tagieva, “Removal of the difference between characteristic and real age in the magnetar model from the analysis of spectral properties of AXPs, SGRs and DRQNSs,” INTERNATIONAL JOURNAL OF MODERN PHYSICS D, pp. 1333–1362, 2003, Accessed: 00, 2020. [Online]. Available: