scholarly journals Radio timing in a millisecond pulsar – extreme/intermediate mass ratio binary system

2020 ◽  
Vol 644 ◽  
pp. A167
Author(s):  
T. Kimpson ◽  
K. Wu ◽  
S. Zane
Keyword(s):  
Globular Clusters ◽  
Relativistic Effects ◽  
Propagation Delay ◽  
Higher Order ◽  
Galactic Centre ◽  
Millisecond Pulsar ◽  
Fundamental Physics ◽  
Timing Model ◽  
Pulsar Timing ◽  
Timing Models

Radio timing observations of a millisecond pulsar in orbit around the Galactic centre black hole (BH) or a BH at the centre of globular clusters could answer foundational questions in astrophysics and fundamental physics. Pulsar radio astronomy typically employs the post-Keplerian approximation to determine the system parameters. However, in the strong gravitational field around the central BH, higher order relativistic effects may become important. We compare the pulsar timing delays given by the post-Keplerian approximation with those given by a relativistic timing model. We find significant discrepancies between the solutions derived for the Einstein delay and the propagation delay (i.e. Roemer and Sharpiro delay) compared to the fully relativistic solutions. Correcting for these higher order relativistic effects is essential in order to construct accurate radio timing models for pulsar systems at the Galactic centre and the centre of globular clusters and informing issues related to their detection.

scholarly journals Gravitational burst radiation from pulsars in the Galactic centre and stellar clusters

2020 ◽  
Vol 495 (1) ◽  
pp. 600-613 ◽  
Author(s):  
Tom Kimpson ◽  
Kinwah Wu ◽  
Silvia Zane
Keyword(s):  
Gravitational Radiation ◽  
Globular Clusters ◽  
Radio Signal ◽  
Strong Field ◽  
Galactic Centre ◽  
Stellar Clusters ◽  
Mass Ratio ◽  
Pulsar Radio ◽  
Orbital Parameters ◽  
Pulsar Timing

ABSTRACT Pulsars (PSRs) orbiting intermediate or supermassive black holes at the centre of galaxies and globular clusters are known as Extreme Mass Ratio Binaries (EMRBs) and have been identified as precision probes of strong-field GR. For appropriate orbital parameters, some of these systems may also emit gravitational radiation in a ‘burst-like’ pattern. The observation of this burst radiation in conjunction with the electromagnetic radio timing signal would allow for multimessenger astronomy in strong-field gravitational regimes. In this work we investigate gravitational radiation from these PSR-EMRBs, calculating the waveforms and SNRs and explore the influence of this GW on the pulsar radio signal. We find that for typical PSR-EMRBs, gravitational burst radiation should be detectable from both the Galactic centre and the centre of stellar clusters, and that this radiation will not meaningfully affect the pulsar timing signal, allowing PSR-EMRB to remain ‘clean’ test-beds of strong-field GR.

scholarly journals Testing the Universality of Free Fall with the Triple System J0337+1715

2017 ◽  
Vol 13 (S337) ◽  
pp. 138-141 ◽  
Author(s):  
A. M. Archibald ◽  
N. V. Gusinskaia ◽  
J. W. T. Hessels ◽  
D. R. Lorimer ◽  
R. S. Lynch ◽  
...  
Keyword(s):  
White Dwarf ◽  
Triple System ◽  
Free Fall ◽  
Analysis Procedure ◽  
Time Of Arrival ◽  
Pulse Time ◽  
Millisecond Pulsar ◽  
Timing Model ◽  
Universality Of Free Fall ◽  
Pulsar Timing

AbstractThe millisecond pulsar PSR J0337+1715 is in a mildly relativistic hierarchical triple system with two white dwarfs. This offers the possibility of testing the universality of free fall: does the neutron star fall with the same acceleration as the inner white dwarf in the gravity of the outer white dwarf? We have carried out an intensive pulsar timing campaign, yielding some 27000 pulse time-of-arrival (TOA) measurements with a median uncertainty of 1.2 μs. Here we describe our analysis procedure and timing model.

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.

scholarly journals Long-term observations of pulsars in the globular clusters 47 Tucanae and M15

2017 ◽  
Vol 13 (S337) ◽  
pp. 251-254
Author(s):  
A. Ridolfi ◽  
P. C. C. Freire ◽  
M. Kramer ◽  
C. G. Bassa ◽  
F. Camilo ◽  
...  
Keyword(s):  
Gravitational Potential ◽  
Globular Clusters ◽  
Higher Order ◽  
The Other ◽  
Line Of Sight ◽  
Physical Parameters ◽  
Spin Period ◽  
Emission Beam ◽  
System Geometry

AbstractMulti-decade observing campaigns of the globular clusters 47 Tucanae and M15 have led to an outstanding number of discoveries. Here, we report on the latest results of the long-term observations of the pulsars in these two clusters. For most of the pulsars in 47 Tucanae we have measured, among other things, their higher-order spin period derivatives, which have in turn provided stringent constraints on the physical parameters of the cluster, such as its distance and gravitational potential. For M15, we have studied the relativistic spin precession effect in PSR B2127+11C. We have used full-Stokes observations to model the precession effect, and to constrain the system geometry. We find that the visible beam of the pulsar is swiftly moving away from our line of sight and may very soon become undetectable. On the other hand, we expect to see the opposite emission beam sometime between 2041 and 2053.

scholarly journals An Upper Limit to the Mass Loss from the Centre of the Galaxy

1974 ◽  
Vol 64 ◽  
pp. 36-36
Author(s):  
Arcadio Poveda ◽  
Christine Allen
Keyword(s):  
Mass Loss ◽  
Gravitational Waves ◽  
Mass Distribution ◽  
Globular Clusters ◽  
Loss Rate ◽  
Galactic Centre ◽  
Isotropic Source ◽  
The Past ◽  
Upper Limit ◽  
The Galaxy

A mass loss of 200 M⊙ per year, as conservatively suggested if Weber is detecting gravitational waves from an isotropic source at the galactic centre, is shown to be incompatible with the existence of (a) globular clusters, (b) old wide binaries, if this loss rate has been constant over the past 1010 yr.From the orbit of ω Centauri in the galactic field and its observed mass distribution and tidal radius an upper limit to the mass loss from the galactic centre is found to be 1 M⊙ yr-1 over the past 1010 yr.

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 Statistical analysis of Galactic globular cluster type properties

2020 ◽  
Vol 495 (4) ◽  
pp. 3981-3989
Author(s):  
M Simioni ◽  
A Aparicio ◽  
G Piotto
Keyword(s):  
Globular Clusters ◽  
Principal Component ◽  
Slow Neutron ◽  
Galactic Centre ◽  
Type I ◽  
Type Ii ◽  
Relative Age ◽  
Average Complexity ◽  
Chromosome Maps ◽  
Cluster Type

ABSTRACT The analysis of pseudo-colour diagrams, the so-called chromosome maps, of Galactic globular clusters (GCs) permits to classify them into type I and type II clusters. Type II GCs are characterized by an above-the-average complexity of their chromosome maps and some of them are known to display star-to-star variations of slow neutron-capture reaction elements including iron. This is at the basis of the hypothesis that type II GCs may have an extragalactic origin and were subsequently accreted by the Milky Way. We performed a principal component analysis to explore possible correlations among various GCs parameters in the light of this new classification. The analysis revealed that cluster type correlates mainly with relative age. The cause of this relation was further investigated finding that more metal-rich type II clusters, also appear to be younger and more distant from the Galactic centre. A depletion of type II clusters for positive values of Galactic coordinate Z was also observed, with no type II clusters detected above Z ∼ 2 kpc. Type II cluster orbits also have larger eccentricities than type I ones.

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.

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