scholarly journals The minimum magnetic field of millisecond pulsars calculated according to accretion: application to the X-ray neutron star SAX J1808.4–3658 in a low-mass X-ray binary

2018 ◽  
Vol 480 (1) ◽  
pp. 692-696 ◽  
Author(s):  
Y Y Pan ◽  
C M Zhang ◽  
L M Song ◽  
N Wang ◽  
D Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Low Mass

scholarly journals Hard-tail emission in the soft state of low-mass X-ray binaries and their relation to the neutron star magnetic field

2016 ◽  
Vol 68 (4) ◽  
pp. 50
Author(s):  
Kazumi Asai ◽  
Tatehiro Mihara ◽  
Masaru Mastuoka ◽  
Mutsumi Sugizaki
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
X Ray ◽  
Soft State ◽  
Low Mass ◽  
X Ray Binaries

scholarly journals XTE J1701–462 AND ITS IMPLICATIONS FOR THE NATURE OF SUBCLASSES IN LOW-MAGNETIC-FIELD NEUTRON STAR LOW-MASS X-RAY BINARIES

2010 ◽  
Vol 719 (1) ◽  
pp. 201-212 ◽  
Author(s):  
Jeroen Homan ◽  
Michiel van der Klis ◽  
Joel K. Fridriksson ◽  
Ronald A. Remillard ◽  
Rudy Wijnands ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
X Ray ◽  
Low Mass ◽  
Low Magnetic Field ◽  
X Ray Binaries

scholarly journals A strange star scenario for the formation of isolated millisecond pulsars

2020 ◽  
Vol 633 ◽  
pp. A45 ◽  
Author(s):  
Long Jiang ◽  
Na Wang ◽  
Wen-Cong Chen ◽  
Xiang-Dong Li ◽  
Wei-Min Liu ◽  
...  
Keyword(s):  
Neutron Star ◽  
Galactic Plane ◽  
Critical Mass ◽  
Strange Star ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Mass Distributions ◽  
The Galaxy ◽  
Low Mass ◽  
X Ray Binaries

According to the recycling model, neutron stars in low-mass X-ray binaries were spun up to millisecond pulsars (MSPs), which indicates that all MSPs in the Galactic plane ought to be harbored in binaries. However, about 20% Galactic field MSPs are found to be solitary. To interpret this problem, we assume that the accreting neutron star in binaries may collapse and become a strange star when it reaches some critical mass limit. Mass loss and a weak kick induced by asymmetric collapse during the phase transition (PT) from neutron star to strange star can result in isolated MSPs. In this work, we use a population-synthesis code to examine the PT model. The simulated results show that a kick velocity of ∼60 km s−1 can produce ∼6 × 103 isolated MSPs and birth rate of ∼6.6 × 10−7 yr−1 in the Galaxy, which is approximately in agreement with predictions from observations. For the purpose of comparisons with future observation, we also give the mass distributions of radio and X-ray binary MSPs, along with the delay time distribution.

scholarly journals On the connection between accreting X-ray and radio millisecond pulsars

2012 ◽  
Vol 8 (S290) ◽  
pp. 141-144
Author(s):  
T. M. Tauris
Keyword(s):  
Mass Transfer ◽  
Neutron Star ◽  
Stellar Evolution ◽  
Roche Lobe ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Braking Torque ◽  
Low Mass ◽  
Spin Distributions

AbstractFor many years it has been recognized that the terminal stages of mass transfer in a low-mass X-ray binary (LMXB) should cause the magnetosphere of the accreting neutron star to expand, leading to a braking torque acting on the spinning pulsar. After the discovery of radio millisecond pulsars (MSPs) it was therefore somewhat a paradox (e.g. Ruderman et al. 1989) how these pulsars could retain their fast spins following the Roche-lobe decoupling phase, RLDP. Here I present a solution to this so-called “turn-off problem” which was recently found by combining binary stellar evolution models with torque computations (Tauris 2012). The solution is that during the RLDP the spin equilibrium of the pulsar is broken and therefore it remains a fast spinning object. I briefly discuss these findings in view of the two observed spin distributions in the populations of accreting X-ray millisecond pulsars (AXMSPs) and radio MSPs.

scholarly journals The study of multipeaked type-I X-ray bursts in the neutron star low-mass X-ray binary 4U 1636 − 536 with RXTE

2020 ◽  
Vol 501 (1) ◽  
pp. 168-178
Author(s):  
Chen Li ◽  
Guobao Zhang ◽  
Mariano Méndez ◽  
Jiancheng Wang ◽  
Ming Lyu
Keyword(s):  
Neutron Star ◽  
Flux Ratio ◽  
Light Curves ◽  
Type I ◽  
X Ray ◽  
Soft State ◽  
Peak Flux ◽  
Low Mass ◽  
Two Peaks ◽  
Second Peak

ABSTRACT We have found and analysed 16 multipeaked type-I bursts from the neutron-star low-mass X-ray binary 4U 1636 − 53 with the Rossi X-ray Timing Explorer (RXTE). One of the bursts is a rare quadruple-peaked burst that was not previously reported. All 16 bursts show a multipeaked structure not only in the X-ray light curves but also in the bolometric light curves. Most of the multipeaked bursts appear in observations during the transition from the hard to the soft state in the colour–colour diagram. We find an anticorrelation between the second peak flux and the separation time between two peaks. We also find that in the double-peaked bursts the peak-flux ratio and the temperature of the thermal component in the pre-burst spectra are correlated. This indicates that the double-peaked structure in the light curve of the bursts may be affected by enhanced accretion rate in the disc, or increased temperature of the neutron star.

scholarly journals A Machine Learning Approach For Classifying Low-mass X-ray Binaries Based On Their Compact Object Nature

2020 ◽  
Author(s):  
R Pattnaik ◽  
K Sharma ◽  
K Alabarta ◽  
D Altamirano ◽  
M Chakraborty ◽  
...  
Keyword(s):  
Machine Learning ◽  
Black Hole ◽  
Neutron Star ◽  
Binary Systems ◽  
Compact Object ◽  
X Ray ◽  
Average Accuracy ◽  
Machine Learning Approach ◽  
Low Mass ◽  
X Ray Binaries

Abstract Low Mass X-ray binaries (LMXBs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. It is challenging to unambiguously determine whether a LMXB hosts a black hole or a neutron star. In the last few decades, multiple observational works have tried, with different levels of success, to address this problem. In this paper, we explore the use of machine learning to tackle this observational challenge. We train a random forest classifier to identify the type of compact object using the energy spectrum in the energy range 5-25 keV obtained from the Rossi X-ray Timing Explorer archive. We report an average accuracy of 87±13% in classifying the spectra of LMXB sources. We further use the trained model for predicting the classes for LMXB systems with unknown or ambiguous classification. With the ever-increasing volume of astronomical data in the X-ray domain from present and upcoming missions (e.g., SWIFT, XMM-Newton, XARM, ATHENA, NICER), such methods can be extremely useful for faster and robust classification of X-ray sources and can also be deployed as part of the data reduction pipeline.

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