Spin-up of the hyperon-softened accreting neutron stars
نویسندگان
چکیده
We study the spin-up of the accreting neutron stars with a realistic hyperon-softened equation of state. Using precise 2-D calculations we study the evolutionary tracks of accreting neutron stars in the frequency baryon-mass and angular-momentum frequency plane. In contrast to the case of spinning-down solitary radiopulsars, where a strong back-bending behavior has been observed, we do not see back-bending phenomenon in the accretion-powered spinning-up case. We conclude that in case of accretion-driven spin-up the back-bending is strongly suppressed by the mass-increase effect accompanying the angular-momentum increase.
منابع مشابه
Spin and Isospin Asymmetry, Equation of State and Neutron Stars
In the present work, we have obtained the equation of state for neutron star matter considering the in uence of the ferromagnetic and antiferromagnetic spin state. We have also investigated the structure of neutron stars. According to our results, the spin asymmetry stiens the equation of state and leads to high mass for the neutron star.
متن کاملHyperon softening of the EOS of dense matter and the spin evolution of isolated neutron stars
The effect of the hyperon softening of the equation of state (EOS) of dense matter on the spin evolution of isolated neutron stars is studied for a broad set of hyperonic EOSs. We use a multidomain 2-D code based on a spectral method, and show how important the precision of solving the equations of stationary motion is for the stability analysis. For some EOSs, the hyperon softening leads to sp...
متن کاملDo we see accreting magnetars in X-ray pulsars?
Strong magnetic field of accreting neutron stars (10 G) is hard to probe by Xray spectroscopy but can be indirectly inferred from spin-up/spin-down measurement in X-ray pulsars. The existing observations of slowly rotating X-ray pulsars are discussed. It is shown that magnetic fields of neutron stars derived from these observations (or lower limits in some cases) fall within the standard 10-10 ...
متن کاملGravitational Waves and the Maximum Spin Rate of Accreting Neutron Stars
Accreting neutron stars in the weakly magnetic Low-Mass XRay Binaries (LMXBs) are expected to be spun up near the breakup frequency ∼> 1 kHz in a small fraction of their age. The lack of observed systems above ∼ 600−700Hz has led to the suggestion that gravitational-wave spindown torque may be setting a maximum rotation rate. If true, searches for sub-millisecond radio pulsars will not be succe...
متن کاملPeriod Distribution of Old Accreting Isolated Neutron Stars
In this paper we present calculations of period distribution for old accreting isolated neutron stars (INSs). After few billion years of evolution low velocity INSs come to the stage of accretion. At this stage INS's period evolution is governed by magnetic braking and angular momentum accreted. Since the interstellar medium is turbulized accreted momentum can either accelerate or decelerate sp...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005