arXiv subjects

Efe Yazgan

Publications and source records attributed to Efe Yazgan.

22 records · Page 2Linked to original sources

arXiv2005

An Approach to Explain the Long Cooling Times of Anomalous X-ray Pulsars and Soft Gamma Repeaters with the Neutrino Magnetic Moment

The surface temperatures as well as X-ray luminosities of Anomalous X-ray Pulsars and Soft Gamma Repeaters are several times higher than that of the ordinary isolated neutron stars at similar ages. We present a simple approach to explain this observation by the effect of the neutrino magnetic moment on neutron star cooling. This requires a neutrino magnetic moment about $(3-5)\times10^{-11}μ_B$. The simple approach presented in this paper might be used in determining the exact value of the neutrino magnetic moment and its contribution to the neutrino-electron scattering when the models to explain Anomalous X-ray Pulsars and Soft Gamma Repeaters are mature enough.

astro-ph↗

arXiv2002

A Trustworthy and Simple Method to Determine Pulsar Distances and the Electron Distribution in the Galaxy

We present the model for determination of pulsar distances or average electron distribution using a method similar to the widely used dependence of A$_V$ on distances in different directions. To have reliable pulsar distances, we have used several natural requirements and distances of pulsar-calibrators. We have constructed dispersion measure-distance relations for pulsars in 48 different directions.

astro-ph↗

arXiv2002

On Period and Burst Histories of AXPs and SGRs and the Possible Evolution of these Objects on the P-Pdot Diagram

In this paper, timing data for all of the 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-Pdot diagram for pulsars, X-ray binaries, anomalous X-ray pulsars, soft gamma repeaters and dim radio quiet netron stars is constructed. The possible evolutionary tracks for anomalous X-ray pulsars, soft gamma repeaters and dim radio quiet netron stars are examined.

astro-ph↗

arXiv2001

Pulsar Spindown by a Fall-Back Disk and the P-P_dot Diagram

Neutron stars may be surrounded by fall-back disks formed from supernova core-collapse. If the disk circumscribes the light-cylinder, the neutron star will be an active radio pulsar spinning down under the propeller spin-down torque applied by the disk as well as the usual magnetic dipole radiation torque. Evolution across the P-P_dot diagram is very rapid when pulsar spin-down is dominated by the propeller torque. This explains the distribution of pulsars in the P-P_dot diagram.

astro-ph↗