scholarly journals Polarimetric Observations of PSR J0437–4715

1996 ◽  
Vol 160 ◽  
pp. 249-251
Author(s):  
José Navarro ◽  
R. N. Manchester
Keyword(s):  
Neutron Star ◽  
Radio Emission ◽  
Time Resolution ◽  
High Time Resolution ◽  
Millisecond Pulsar ◽  
Millisecond Pulsars ◽  
Large Bandwidth ◽  
Pulsar Timing ◽  
Field Geometry ◽  
Star Surface

To date there have been few polarimetric observations of millisecond pulsars, mainly due to the instrumental challenge of simultaneous high time resolution and large bandwidth. Such observations provide our most direct clues to the structure of the magnetic fields around pulsars, and are especially important in the case of millisecond pulsars, where radio emission necessarily originates very close to the neutron star surface.We have observed the bright millisecond pulsar J0437–4715 at the Parkes Radiotelescope with the Caltech Fast Pulsar Timing Machine, at several radio frequencies and in full polarimetric mode. Our analyses show significant deviations from the standard dipole field geometry.

scholarly journals Coherent Dedispersion: History and Results

2017 ◽  
Vol 13 (S337) ◽  
pp. 29-32
Author(s):  
Timothy H. Hankins
Keyword(s):  
Radio Emission ◽  
Real Time ◽  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
Emission Mechanism ◽  
Real Time Processing ◽  
Time Processing ◽  
Pulsar Timing

AbstractThe high time resolution afforded by coherent dedispersion has enabled precision pulsar timing, detailed studies of pulsar morphology, and has led to conclusions about the radio emission mechanism. The advance of technology in the last 50 years has enhanced the capability of coherent dedispersion, now used for most pulsar observing, by nearly six orders of magnitude. Although coherent dedispersion is now done mostly in software, in “earlier days” several novel hardware devices for real-time processing were developed.

scholarly journals Millisecond Pulsars

1989 ◽  
Vol 8 ◽  
pp. 161-165
Author(s):  
J.H. Krolik
Keyword(s):  
Neutron Star ◽  
Stellar Evolution ◽  
Close Binary ◽  
Millisecond Pulsar ◽  
Millisecond Pulsars ◽  
Physical Conditions ◽  
Cast Doubt ◽  
Standard Picture ◽  
The Universe ◽  
New System

AbstractMillisecond pulsars are intrinsically interesting because they illustrate some of the most extreme physical conditions to be found anywhere in the Universe, and because their evolution exhibits several stages of great drama. It had been widely believed for several years that spin-up of an old neutron star by accretion from a close stellar companion explained their fast rotation, but the absence of companions in several cases cast doubt on that picture. This spring a millisecond pulsar in a close binary was discovered in which the companion appears to be evaporating, thus reconciling the existence of lone millisecond pulsars with the standard picture. Ongoing observations of this new system, and complementary calculations, promise to answer many of the questions remaining about this dramatic phase in stellar evolution.

scholarly journals Ensemble Pulsar Time Study by Pulsar Timing Observations

2004 ◽  
Vol 218 ◽  
pp. 439-440
Author(s):  
Tinggao Yang ◽  
Guangren Ni
Keyword(s):  
Time Scale ◽  
Wavelet Decomposition ◽  
Time Study ◽  
Millisecond Pulsar ◽  
Millisecond Pulsars ◽  
Pulsar Time ◽  
Pulsar Timing ◽  
Timing Data ◽  
Gravitational Wave Background

Long term timing of multiple millisecond pulsars can contribute to the study of an ensemble pulsar time scale PTens. A wavelet decomposition algorithm (WDA) was applied to define a PTens using the available millisecond pulsar timing datA. The PTens obtained from WDA is more stable than those resulting from other algorithms. The Chinese 50 m radio telescope is specially designed for PTens study and detection of gravitational wave background via millisecond pulsars timing observations. A scheme for multiple millisecond pulsar timing and ensemble pulsar time study is discussed in some detail.

The Discovery of 5 Millisecond Pulsars in the High Time Resolution Universe Survey

2011 ◽  
Author(s):  
S. D. Bates ◽  
M. Bailes ◽  
N. D. R. Bhat ◽  
M. Burgay ◽  
S. Burke-Spolaor ◽  
...  
Keyword(s):  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
Millisecond Pulsars

scholarly journals The High Time Resolution Universe Pulsar Survey - IV. Discovery and polarimetry of millisecond pulsars

2011 ◽  
Vol 419 (2) ◽  
pp. 1752-1765 ◽  
Author(s):  
M. J. Keith ◽  
S. Johnston ◽  
M. Bailes ◽  
S. D. Bates ◽  
N. D. R. Bhat ◽  
...  
Keyword(s):  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
Millisecond Pulsars

scholarly journals Thermal X-ray emission identified from the millisecond pulsar PSR J1909–3744

2019 ◽  
Vol 627 ◽  
pp. A141 ◽  
Author(s):  
N. A. Webb ◽  
D. Leahy ◽  
S. Guillot ◽  
N. Baillot d’Etivaux ◽  
D. Barret ◽  
...  
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Thermal Emission ◽  
Black Body ◽  
Millisecond Pulsar ◽  
Distance Measurements ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Link Type

Context. Pulsating thermal X-ray emission from millisecond pulsars can be used to obtain constraints on the neutron star equation of state, but to date only five such sources have been identified. Of these five millisecond pulsars, only two have well-constrained neutron star masses, which improve the determination of the radius via modelling of the X-ray waveform. Aims. We aim to find other millisecond pulsars that already have well-constrained mass and distance measurements that show pulsed thermal X-ray emission in order to obtain tight constraints on the neutron star equation of state. Methods. The millisecond pulsar PSR J1909–3744 has an accurately determined mass, M = 1.54 ± 0.03 M⊙ (1σ error) and distance, D = 1.07 ± 0.04 kpc. We analysed XMM-Newton data of this 2.95 ms pulsar to identify the nature of the X-ray emission. Results. We show that the X-ray emission from PSR J1909–3744 appears to be dominated by thermal emission from the polar cap. Only a single component model is required to fit the data. The black-body temperature of this emission is $ {kT}=0.26^{0.03}_{0.02} $ keV and we find a 0.2–10 keV un-absorbed flux of 1.1 × 10−14 erg cm−2 s−1 or an un-absorbed luminosity of 1.5 × 1030 erg s−1. Conclusion. Thanks to the previously determined mass and distance constraints of the neutron star PSR J1909–3744, and its predominantly thermal emission, deep observations of this object with future X-ray facilities should provide useful constraints on the neutron star equation of state.

scholarly journals Observations of the Millisecond Pulsar PSR 1855+09 At 102 MHz

1992 ◽  
Vol 128 ◽  
pp. 213-213
Author(s):  
A. D. Kuz'min ◽  
Yu. I. Alekseev ◽  
K. A. Lapaev ◽  
B. Ya. Losovsky ◽  
A. A. Salnikov
Keyword(s):  
Radio Emission ◽  
Interstellar Medium ◽  
Short Duration ◽  
Time Scale ◽  
Millisecond Pulsar ◽  
Rotation Effect ◽  
Millisecond Pulsars ◽  
Astrophysical Interest ◽  
Pulsar Time

AbstractThe study of millisecond pulsars is of great astrophysical interest. One may expect that the rotation effect on the structure of the magnetosphere should be very significant. In view of the short duration of the pulses they are very suitable for investigations of the interstellar medium; at least they hold the promise for the pulsar time scale.Millisecond pulsars were discovered and have been studied on the basis of their radio-emission at decimeter wavelengths. At longer wavelengths scattering of the radio emission in the interstellar medium is the principal limitation of millisecond pulsar observations.

scholarly journals High-Precision Timing of Millisecond Pulsars and Precision Astrometry

1995 ◽  
Vol 166 ◽  
pp. 163-171 ◽  
Author(s):  
V. M. Kaspi
Keyword(s):  
Solar System ◽  
High Precision ◽  
Reference Frames ◽  
Millisecond Pulsar ◽  
Millisecond Pulsars ◽  
Pulsar Timing ◽  
Solar System Objects ◽  
Optical Reference ◽  
Precision Astrometry

We present the technique of long-term, high-precision timing of millisecond pulsars as applied to precision astrometry. We provide a tutorial on pulsars and pulsar timing, as well as up-to-date results of long-term timing observations of two millisecond pulsars, PSRs B1855+09 and B1937+21. We consider the feasibility of tying the extragalactic and optical reference frames to that defined by solar system objects, and we conclude that precision astrometry from millisecond pulsar timing has a bright future.

scholarly journals Millisecond Pulsar Timing in Effelsberg

1996 ◽  
Vol 160 ◽  
pp. 95-96 ◽  
Author(s):  
M. Kramer ◽  
O. Doroshenko ◽  
A. Jessner ◽  
R. Wielebinski ◽  
A. Wolszczan ◽  
...  
Keyword(s):  
Millisecond Pulsar ◽  
Millisecond Pulsars ◽  
Polarization Measurements ◽  
Pulsar Timing ◽  
Short Period

Millisecond pulsar as clocks are excellent tools for studying a variety of phenomena in physics and astrophysics (e.g. Foster & Backer 1990). We have been observing millisecond pulsars with the 100–m Effelsberg radiotelescope since April 1994. Initially, the goal of this program was to help continuing the timing of Arecibo pulsars during the upgrade–related shutdown period of the 305–m radiotelescope. Gradually, the program has evolved to time and study the emission physics of all short period pulsars detectable from Effelsberg. In particular, polarization measurements are used to make inferences about the emission physics of millisecond pulsars (cf. Xilouris & Kramer, this proceeding). At present, the programme involves approximately monthly observations of a set of 22 sources.

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.

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