scholarly journals The Discovery of the Most Accelerated Binary Pulsar

2017 ◽  
Vol 13 (S337) ◽  
pp. 134-137
Author(s):  
Andrew D. Cameron
Keyword(s):  
Neutron Star ◽  
Orbital Period ◽  
Binary Systems ◽  
Galactic Plane ◽  
Low Latitude ◽  
Binary Pulsar ◽  
Binary Pulsars ◽  
Searching Strategy ◽  
Theories Of Gravity ◽  
Relativistic Parameter

AbstractPulsars in relativistic binary systems have emerged as fantastic natural laboratories for testing theories of gravity, the most prominent example being the double pulsar, PSR J0737–3039. The HTRU-South Low Latitude pulsar survey represents one of the most sensitive blind pulsar surveys taken of the southern Galactic plane to date, and its primary aim has been the discovery of new relativistic binary pulsars. Here we present our binary pulsar searching strategy and report on the survey’s flagship discovery, PSR J1757–1854. A 21.5-ms pulsar in a relativistic binary with an orbital period of 4.4 hours and an eccentricity of 0.61, this double neutron star (DNS) system is the most accelerated pulsar binary known, and probes a relativistic parameter space not yet explored by previous pulsar binaries.

scholarly journals Binary pulsar evolution: unveiled links and new species

2012 ◽  
Vol 8 (S291) ◽  
pp. 121-126
Author(s):  
Andrea Possenti
Keyword(s):  
New Species ◽  
Neutron Star ◽  
Evolutionary Path ◽  
Binary Pulsar ◽  
Galactic Field ◽  
New Class ◽  
Binary Pulsars ◽  
Low Mass ◽  
Pulsar Searches ◽  
Pulsar Evolution

AbstractIn the last years a series of blind and/or targeted pulsar searches led to almost triple the number of known binary pulsars in the galactic field with respect to a decade ago. The focus will be on few outliers, which are emerging from the average properties of the enlarged binary pulsar population. Some of them may represent the long sought missing links between two kinds of neutron star binaries, while others could represent the stereotype of new groups of binaries, resulting from an evolutionary path which is more exotic than those considered until recently. In particular, a new class of binaries, which can be dubbed Ultra Low Mass Binary Pulsars (ULMBPs), is emerging from recent data.

scholarly journals The High Time Resolution Universe Pulsar Survey – XVI. Discovery and timing of 40 pulsars from the southern Galactic plane

2020 ◽  
Vol 493 (1) ◽  
pp. 1063-1087 ◽  
Author(s):  
A D Cameron ◽  
D J Champion ◽  
M Bailes ◽  
V Balakrishnan ◽  
E D Barr ◽  
...  
Keyword(s):  
Binary System ◽  
Time Resolution ◽  
Binary Systems ◽  
Total Population ◽  
Galactic Plane ◽  
High Time ◽  
High Time Resolution ◽  
Black Widow ◽  
Low Latitude ◽  
Lower Luminosity

ABSTRACT We present the results of processing an additional 44  per cent of the High Time Resolution Universe South Low Latitude (HTRU-S LowLat) pulsar survey, the most sensitive blind pulsar survey of the southern Galactic plane to date. Our partially coherent segmented acceleration search pipeline is designed to enable the discovery of pulsars in short, highly accelerated orbits, while our 72-min integration lengths will allow us to discover pulsars at the lower end of the pulsar luminosity distribution. We report the discovery of 40 pulsars, including three millisecond pulsar-white dwarf binary systems (PSRs J1537−5312, J1547−5709, and J1618−4624), a black-widow binary system (PSR J1745−23) and a candidate black-widow binary system (PSR J1727−2951), a glitching pulsar (PSR J1706−4434), an eclipsing binary pulsar with a 1.5-yr orbital period (PSR J1653−45), and a pair of long spin-period binary pulsars which display either nulling or intermittent behaviour (PSRs J1812−15 and J1831−04). We show that the total population of 100 pulsars discovered in the HTRU-S LowLat survey to date represents both an older and lower luminosity population, and indicates that we have yet to reach the bottom of the luminosity distribution function. We present evaluations of the performance of our search technique and of the overall yield of the survey, considering the 94  per cent of the survey which we have processed to date. We show that our pulsar yield falls below earlier predictions by approximately 25  per cent (especially in the case of millisecond pulsars), and discuss explanations for this discrepancy as well as future adaptations in RFI mitigation and searching techniques which may address these shortfalls.

scholarly journals Orbital and superorbital periods in ULX pulsars, disc-fed HMXBs, Be/X-ray binaries, and double-periodic variables

2020 ◽  
Vol 495 (1) ◽  
pp. L139-L143
Author(s):  
L J Townsend ◽  
P A Charles
Keyword(s):  
Neutron Star ◽  
Orbital Period ◽  
Binary Systems ◽  
High Mass ◽  
Early Type ◽  
Present Evidence ◽  
X Ray ◽  
Spin Period ◽  
Simple Linear Relationship ◽  
X Ray Binaries

ABSTRACT We present evidence for a simple linear relationship between the orbital period and superorbital period in ultra-luminous X-ray (ULX) pulsars, akin to what is seen in the population of disc-fed neutron star supergiant X-ray binary and Be/X-ray binary systems. We argue that the most likely cause of this relationship is the modulation of precessing hotspots or density waves in an accretion or circumstellar disc by the binary motion of the system, implying a physical link between ULX pulsars and high-mass X-ray binary (HMXB) pulsars. This hypothesis is supported by recent studies of Galactic and Magellanic Cloud HMXBs accreting at super-Eddington rates, and the position of ULX pulsars on the spin period–orbital period diagram of HMXBs. An interesting secondary relationship discovered in this work is the apparent connection between disc-fed HMXBs, ULXs, and a seemingly unrelated group of early-type binaries showing so-called double-periodic variability. We suggest that these systems are good candidates to be the direct progenitors of Be/X-ray binaries.

scholarly journals Interstellar Scintillations and Neutron Star Kinematics

1987 ◽  
Vol 125 ◽  
pp. 35-46
Author(s):  
J.M. Cordes
Keyword(s):  
Monte Carlo ◽  
Neutron Star ◽  
Neutron Stars ◽  
Binary Systems ◽  
Galactic Plane ◽  
Radio Pulsars ◽  
Population Monte Carlo ◽  
Interstellar Scintillation ◽  
Supernova Explosions ◽  
The Mean

The interstellar scintillation technique for measuring neutron star speeds is described and results are given for 71 radio pulsars. The mean transverse neutron star speed is 100 km s−1 and the distribution extends to 300 km s−1. The transverse speed correlates with the z velocity derived independently using distance from the galactic plane, consistent with most neutron stars having been born near the galactic plane. A correlation of transverse speed with the quantity PP ∝ (magnetic moment)2 is a general property of the neutron star population. Monte Carlo simulations of the progenitors of neutron stars show that the velocity distribution is inconsistent with the disruption of binary systems solely by symmetric supernova explosions. Either explosions are asymmetric or there are additional accelerations of neutron stars after their formation.

scholarly journals Timing of Binary Pulsars at Kalyazin, Russia

2004 ◽  
Vol 218 ◽  
pp. 433-434 ◽  
Author(s):  
Yu. P. Ilyasov ◽  
V. V. Oreshko ◽  
V. A. Potapov ◽  
A. E. Rodin
Keyword(s):  
Energy Density ◽  
Gravitational Wave ◽  
High Precision ◽  
Radio Telescope ◽  
Orbital Period ◽  
Binary Pulsar ◽  
Binary Pulsars ◽  
Upper Limits ◽  
Gravitational Wave Background

Regular high-precision timing of the binary pulsars J0613−0200, J1012+5307, J1022+1001, J1640+2224, J1643−1224, J1713+0747, J2145−0750 and the pulsar B1937+21 has been conducted at the Kalyazin (Russia) radio telescope RT-64 at 0.6 GHz over more than 6 years. Several of the pulsars monitored have been found to be good probes for gravitational wave background (GWB) tests, while others, having a shorter orbital period, can be used for establishing a dynamical binary pulsar timescale. Upper limits for the GWB energy density were estimated.

scholarly journals RX J0529.8−6556: a BeXRB pulsar with an evolving optical period and out of phase X-ray outbursts

2021 ◽  
Vol 503 (4) ◽  
pp. 6187-6201
Author(s):  
H Treiber ◽  
G Vasilopoulos ◽  
C D Bailyn ◽  
F Haberl ◽  
K C Gendreau ◽  
...  
Keyword(s):  
Neutron Star ◽  
Orbital Period ◽  
Orbital Plane ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Optical Data ◽  
Pulse Profile ◽  
X Ray ◽  
Binary Pulsar ◽  
Be Star

ABSTRACT We report the results of eROSITA and NICER observations of the 2020 June outburst of the Be/X-ray binary pulsar RX J0529.8−6556 in the Large Magellanic Cloud, along with the analysis of archival X-ray and optical data from this source. We find two anomalous features in the system’s behaviour. First, the pulse profile observed by NICER during maximum luminosity is similar to that observed by XMM–Newton in 2000, despite the fact that the X-ray luminosity was different by two orders of magnitude. In contrast, a modest decrease in luminosity in the 2020 observations generated a significant change in pulse profile. Secondly, we find that the historical optical outbursts are not strictly periodic, as would be expected if the outbursts were triggered by periastron passage, as is generally assumed. The optical peaks are also not coincident with the X-ray outbursts. We suggest that this behaviour may result from a misalignment of the Be star disc and the orbital plane, which might cause changes in the timing of the passage of the neutron star through the disc as it precesses. We conclude that the orbital period of the source remains unclear.

scholarly journals Ultra-Short Period Double-Degenerate Binaries

2004 ◽  
Vol 190 ◽  
pp. 324-337 ◽  
Author(s):  
Mark Cropper ◽  
Gavin Ramsay ◽  
Kinwah Wu ◽  
Pasi Hakala
Keyword(s):  
Neutron Star ◽  
Gravitational Wave ◽  
Orbital Period ◽  
Binary Systems ◽  
Star Model ◽  
X Ray ◽  
Compact Binaries ◽  
Short Period ◽  
Observational Status ◽  
Strong Gravitational Wave

AbstractWe review the current observational status of the ROSAT sources RX J1914.4+2456 and RX J0806.3+1527, and the evidence that these are ultra-short period (< 10 min) binary systems. We argue that an Intermediate Polar interpretation can be ruled out, that they are indeed compact binaries with a degenerate secondary, and that the period seen in the X-ray and optical is the orbital period. A white dwarf primary is preferred, but a neutron star cannot be excluded. We examine the capability of the three current double-degenerate models (Polar, Direct Accretor and Electric Star) to account for the observational characteristics of these systems. All models have difficulties with some aspects of the observations, but none can be excluded with confidence at present. The Electric Star model provides the best description, but the lifetime of this phase requires further investigation. These ultra-short period binaries will be strong gravitational wave emitters in the LISA bandpass, and because of their known source properties will be important early targets for gravitational wave studies.

scholarly journals Intermediate-Mass Binary Pulsars: a New Class of Objects?

1996 ◽  
Vol 160 ◽  
pp. 539-540
Author(s):  
F. Camilo
Keyword(s):  
Radio Telescope ◽  
Orbital Period ◽  
White Dwarf ◽  
Binary Systems ◽  
Intermediate Mass ◽  
Circular Orbits ◽  
Millisecond Pulsars ◽  
New Class ◽  
Binary Pulsars ◽  
The Galaxy

Approximately 4/5 of the ∼ 35 millisecond pulsars known in the disk of the Galaxy are in binary systems. The vast majority of these binary pulsars have (presumed) helium white dwarf companions with massesm2&lt; 0.45 M⊙, spin periodsP&lt; 10 ms, and all are in extremely circular orbits (Fig. 1). In a search for millisecond pulsars with the Arecibo radio telescope, we have recently discovered PSR J1022+1001, a 16.45 ms pulsar in a 7.8 d orbit with a companion that is at least 0.73 M⊙, and is more likely as massive as 0.8−1.0M⊙; and PSR J0621+1002, a 28.85 ms pulsar in an 8.3 d orbit with a companion at least 0.45 M⊙, and more likely withm2≈ 0.54 M⊙. One other system, PSR J2145–0750, hasP= 16.05 ms, orbital periodPb= 6.8 d, andm2≈ 0.50 M⊙(see Table 1).

scholarly journals Monte Carlo Simulations of Radio Pulsars and Their Progenitors

1987 ◽  
Vol 125 ◽  
pp. 408-408
Author(s):  
Rachel J. Dewey ◽  
James M. Cordes
Keyword(s):  
Neutron Star ◽  
Velocity Distribution ◽  
Neutron Stars ◽  
Binary Systems ◽  
Stellar Population ◽  
Main Sequence ◽  
Radio Pulsar ◽  
Close Binary ◽  
Radio Pulsars ◽  
Binary Pulsars

The formation of neutron stars in binary systems is often used to explain the nature of specific radio pulsars and characteristics of the pulsar population as a whole. We have investigated the extent to which such scenarios provide a self-consistent description of the pulsar population. Using a computer simulation, we modeled the evolution of the main sequence stellar population and compared the predicted neutron star population to the observed radio pulsar population, focusing our attention on the pulsar velocity distribution and the incidence of binary pulsars. These characteristics relate very directly to the binary nature of pulsar progenitors, and are not strongly dependent on models of pulsar magentic field and luminosity evolution.The need to reproduce both the high velocities typical of pulsars and the low incidence of binary pulsars strongly constrains the formation of pulsars in binary systems. Unless one assumes that virtually all pulsars originate in close binary systems, the observed velocity distribution cannot result from the disruption of binary systems by symmetric supernova explosions; some additional acceleration process (e.g. asymmetric supernova mass ejection or asymmetries in pulsar radiation) must act during or soon after a pulsar's formation. It is possible to reproduce the velocity distribution by assuming that all pulsars are born in binary systems with initial orbital periods less than about 30 years. However, the predicted incidence of binaries is then too large by more than an order of magnitude, unless one also assumes that the process of mass transfer from the primary to the secondary is almost always non-conservative, or that the minimum mass necessary for a stripped helium core to explode as a supernova is larger (over 4 M⊙) than currently believed. Further analyses of the radio pulsar population, the X-ray binary population and the abundances of elements ejected in supernovae should help determine which of these alternatives is most reasonble. Additional studies of the main sequence stellar population, accounting more accurately for evolutionary and observational selection effects, will reduce the uncertainties in modeling the formation of the neutron star population.It has also been suggested that the observed correlation between pulsar velocities and magnetic moments (see Cordes, these Proceedings) is induced by the differing evolutionary paths by which stars in binary systems form radio pulsars. Our simulation does not reproduce this correlation, and we do not find any paths likely to produce low velocity, low magnetic field neutron stars not in binary systems.We are submitting a full description of our model and results to The Astrophysical Journal.

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