scholarly journals Orbital spin dynamics of a millisecond pulsar around a massive BH with a general mass quadrupole

2020 ◽  
Vol 497 (4) ◽  
pp. 5421-5431 ◽  
Author(s):  
Tom Kimpson ◽  
Kinwah Wu ◽  
Silvia Zane
Keyword(s):  
Spin Dynamics ◽  
Momentum Tensor ◽  
Orbital Dynamics ◽  
Galactic Centre ◽  
Millisecond Pulsar ◽  
Pulse Profile ◽  
Spin Orbital ◽  
Linear Interaction ◽  
General Mass ◽  
Mass Quadrupole

ABSTRACT We investigate the spin dynamics of a millisecond pulsar (MSP) in compact orbit around a Kerr-like massive BH with an general mass quadrupole. We use the Mathisson–Papetrou–Dixon formulation to compute the orbital and spin evolution of the MSP, accounting for the non-linear interaction of the pulsar’s energy–momentum tensor on the background space–time metric. We investigate how the MSP spin and BH quadrupole moment manifest in the pulsar spin-orbital dynamics. We discuss the astrophysical observational implications of these spin and orbital dynamics on the timing of a radio pulsar in an extreme mass ratio binary, e.g. a Galactic Centre pulsar. In particular, notable timing variations in the Einstein delay and Roemer delay are observed, along with modifications to the pulsar pulse profile.

scholarly journals Unusual frequency dependence of the integrated profile of the millisecond pulsar PSR J2145-0705

1996 ◽  
Vol 160 ◽  
pp. 285-286
Author(s):  
A.D. Kuzmin ◽  
B.Ya. Losovski
Keyword(s):  
Frequency Dependence ◽  
Radio Telescope ◽  
High Frequency ◽  
Separation Method ◽  
Dependence Analysis ◽  
Millisecond Pulsar ◽  
Pulse Profile ◽  
Component Structure ◽  
Frequency Measurements ◽  
Gaussian Fit

We report on observations and frequency dependence analysis of the integrated profile of the millisecond pulsar PSR J2145-0705. Observations were performed at 102 MHz with the BSA radio telescope in Pushchino.To analyze the frequency dependence of the integrated profile we supplemented our data with high frequency measurements by Bailes et al. (unpublished). For frequency dependence analysis we used the Gaussian fit separation method of presentation the integrated pulse profile as a superposition of Gaussian-shaped individual components (Wu, Xu and Rankin 1992; Foster, Fairhead and Backer 1991). A good fit is provided by four component structure, suggested by Bailes et al. 1994.

scholarly journals Mode changing in the Black Widow Pulsar

2017 ◽  
Vol 13 (S337) ◽  
pp. 368-369
Author(s):  
Nikhil Mahajan ◽  
Marten van Kerkwijk
Keyword(s):  
Global Change ◽  
Millisecond Pulsar ◽  
Black Widow ◽  
Pulse Profile ◽  
Mode Change ◽  
Multiple Components

AbstractMode changing is a phenomenon where a pulsar’s emission abruptly changes between two or more quasi-stable modes. We have discovered mode changing in the Black Widow Pulsar (PSR B1957+20), a first detection of mode changing in a millisecond pulsar. On average, a mode change occurs every 1.7 seconds. Multiple components across the pulse profile participate in the mode changing, indicating that this is likely caused by a global change in the pulsar’s magnetosphere.

scholarly journals Likely detection of pulsed high-energy γ-rays from millisecond pulsar PSR J0218+4232

2000 ◽  
Vol 177 ◽  
pp. 355-358
Author(s):  
L. Kuiper ◽  
W. Hermsen ◽  
F. Verbunt ◽  
A. Lyne ◽  
I. Stairs ◽  
...  
Keyword(s):  
Timing Analysis ◽  
High Energy ◽  
X Rays ◽  
Millisecond Pulsar ◽  
Imaging Analysis ◽  
Pulse Profile ◽  
Significance Level ◽  
Absolute Phase ◽  
Bl Lac ◽  
Γ Rays

AbstractWe report on the likely detection of pulsed high-energyγ-rays from the binary millisecond pulsar PSR J0218+4232 in 100–1000 MeV data from CGRO EGRET. Imaging analysis demonstrates that the highly significantγ-ray source 2EG J0220+4228 (∼ 10σ) is for energies > 100 MeV positionally consistent with both PSR J0218+4232 and the BL Lac 3C66A. However, above 1 GeV 3C66A is the evident counterpart, whereas between 100 and 300 MeV PSR J0218+4232 is the most likely one. Timing analysis using one ephemeris valid for all EGRET observations yields in the 100-1000 MeV range a double-pulse profile at a ∼ 3.5σsignificance level. The phase separation is similar to the component separation of ∼ 0.47 observed at X-rays. A comparison of theγ-ray profile with the 610 MHz radio profile in absolute phase shows that the twoγ- ray pulses coincide with two of the three emission features in the complex radio profile.

scholarly journals Timing of the accreting millisecond pulsar IGR J17591–2342: evidence of spin-down during accretion

2020 ◽  
Vol 495 (2) ◽  
pp. 1641-1649
Author(s):  
A Sanna ◽  
L Burderi ◽  
K C Gendreau ◽  
T Di Salvo ◽  
P S Ray ◽  
...  
Keyword(s):  
Neutron Star ◽  
Timing Analysis ◽  
Millisecond Pulsar ◽  
Pulse Profile ◽  
X Ray ◽  
Observed Behaviour ◽  
October 17 ◽  
Refined Estimate ◽  
Star Surface ◽  
Orbital Solution

ABSTRACT We report on the phase-coherent timing analysis of the accreting millisecond X-ray pulsar IGR J17591–2342, using Neutron Star Interior Composition Explorer (NICER) data taken during the outburst of the source between 2018 August 15 and 2018 October 17. We obtain an updated orbital solution of the binary system. We investigate the evolution of the neutron star spin frequency during the outburst, reporting a refined estimate of the spin frequency and the first estimate of the spin frequency derivative ($\dot{\nu }\sim -7\times 10^{-14}$ Hz s−1), confirmed independently from the modelling of the fundamental frequency and its first harmonic. We further investigate the evolution of the X-ray pulse phases adopting a physical model that accounts for the accretion material torque as well as the magnetic threading of the accretion disc in regions where the Keplerian velocity is slower than the magnetosphere velocity. From this analysis we estimate the neutron star magnetic field Beq = 2.8(3) × 108 G. Finally, we investigate the pulse profile dependence on energy finding that the observed behaviour of the pulse fractional amplitude and lags as a function of energy is compatible with the down-scattering of hard X-ray photons in the disc or the neutron star surface.

scholarly journals Finite-temperature spin dynamics and phase transitions in spin-orbital models

2009 ◽  
Vol 80 (18) ◽  
Author(s):  
C.-C. Chen ◽  
B. Moritz ◽  
J. van den Brink ◽  
T. P. Devereaux ◽  
R. R. P. Singh
Keyword(s):  
Phase Transitions ◽  
Finite Temperature ◽  
Spin Dynamics ◽  
Spin Orbital

scholarly journals Optically and Electrically Controllable Adatom Spin–orbital Dynamics in Transition Metal Dichalcogenides

Nano Letters ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 6721-6726 ◽  
Author(s):  
Bin Shao ◽  
Malte Schüler ◽  
Gunnar Schönhoff ◽  
Thomas Frauenheim ◽  
Gerd Czycholl ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metal Dichalcogenides ◽  
Orbital Dynamics ◽  
Spin Orbital ◽  
Metal Dichalcogenides

scholarly journals The Future of Pulsar Timing Arrays

2015 ◽  
Vol 11 (A29B) ◽  
pp. 344-350
Author(s):  
B. W. Stappers
Keyword(s):  
Gravitational Waves ◽  
Millisecond Pulsar ◽  
Medium Effects ◽  
Pulse Profile ◽  
Project Approach ◽  
Science Project ◽  
Pulsar Timing ◽  
Timing Sensitivity ◽  
Pulsar Timing Array ◽  
Made In

AbstractSignificant advances have been made in the sensitivity of pulsar timing arrays for the detection of gravitational waves in the last decade. This presentation looked forward to consider where the development of pulsar timing arrays might go as we head towards the Square Kilometre Array (SKA) and then beyond. I reviewed where progress needs to be made in terms of sensitivity to gravitational waves, including improvements to existing observing approaches and new telescopes such as MeerKAT and FAST and techniques like LEAP. The dramatic increase in the number of millisecond pulsars is presented and how that might affect progress towards a first detection is discussed. Developments in analytic techniques were also discussed, including the removal of interstellar medium effects, red noise and pulse profile variations. A summary of how the SKA can contribute through an increased millisecond pulsar population and pulsar timing sensitivity was presented. With the likelihood that the SKA will implement some form of Key Science Project approach, some ideas of how will this affect how the International Pulsar Timing Array effort and how it might evolve into a KSP were discussed.

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