scholarly journals The Origin of Millisecond Pulsar Velocities

1996 ◽  
Vol 160 ◽  
pp. 51-52
Author(s):  
Thomas M. Tauris
Keyword(s):  
Neutron Star ◽  
Binary System ◽  
Orbital Period ◽  
Main Sequence ◽  
Space Velocity ◽  
Computer Code ◽  
Millisecond Pulsar ◽  
Final State ◽  
Pulsar Velocity ◽  
Orbital Periods

We have developed a computer code (Tauris & Bailes 1996) to follow the evolution of a binary system from the zero-age main sequence to its “final” state as a binary millisecond pulsar (BMSP), at all stages keeping careful track of the mass and orbital separation of the two stars.To help determine the origin of millisecond pulsars, we compute the space velocities predicted by various models of their formation. It is difficult to produce a millisecond pulsar velocity greater than 270 km s−1with any model, unless the formation of the neutron star is accompanied by some form of asymmetric kick. We obtain average 3-D system velocities of 〈vrecoil〉= 99.6, 137.6 and 160.7 km s−1using Gaussian kicks of 〈vkick〉=0, 200 and 450 km s−1(σ=0, 100 and 200 km s - 1, respectively). Our computations show that, in general, we expect those systems with shorter orbital periods to have larger velocities than those with longer periods, but any relation between the final orbital period and space velocity is fairly weak, especially if asymmetries are involved.

scholarly journals Age Dependent Angular Momentum, Orbital Period and Total Mass of Detached Binaries

2011 ◽  
Vol 7 (S282) ◽  
pp. 464-465
Author(s):  
O. Demircan ◽  
M. Tüysüz ◽  
F. Soydugan ◽  
S. Bilir
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Total Mass ◽  
Main Sequence ◽  
Space Velocity ◽  
Angular Momenta ◽  
Age Dependent ◽  
The Mean ◽  
Orbital Periods ◽  
Detached Binaries

AbstractThe orbital angular momenta OAM (J) of detached binaries (including both cool and hot binaries) were estimated and nine subgroups were formed according to their OAM (J) distribution. The mean kinematical ages of all subgroups have been estimated by using their space velocity distributions and, thus, the age dependent variations of the mean OAM (J), orbital period (P), and total mass (M) of all subgroups were investigated. It was discovered that: i) The orbital period of detached binaries with radiative components decrease very slowly during the main sequence (MS) evolution. It is interesting that the large amount of mass loss is almost balanced by the OAM loss, and not much change in the orbital periods is observed. ii) The nuclear evolution of radiative components beyond the MS initiates the increase of the periods until the components have convective upper layers, i.e. until they become later than F5 IV, and the system becomes a cool binary with sub-giant or giant components. iii) The large co-rotating distance of the magnetically-driven wind in cool binaries (CAB) carries out a large amount of OAM and then the periods of such binaries decrease significantly, and the orbits shrink until another effect such as mass transfer dominates the period changes.

Origin of Very-Short Orbital-Period Binary Systems

1983 ◽  
Vol 72 ◽  
pp. 263-267
Author(s):  
Shigeki Miyaji
Keyword(s):  
Binary System ◽  
Globular Cluster ◽  
Orbital Period ◽  
Binary Systems ◽  
Main Sequence ◽  
Cataclysmic Variables ◽  
Close Binaries ◽  
X Ray ◽  
Evolutionary Scenario ◽  
Orbital Periods

Recent observations of four close binaries have established that there is a group of very-short orbital-period (VSOP) binaries whose orbital periods are less than 60 minutes. The VSOP binaries consist of both x-ray close binaries (4U1626-67; Middleditch et al. 1981 and 4U1916 -0.5; White and Swank 1982) and cataclysmic variables (AM CVn; Faulkner et al. 1972 and G61-29; Nather et al. 1981). Their orbital periods are too short to have a main-sequence companion. However, four binaries, none of them belongs to any globular cluster, are too abundant to be explained by capturing mechanism of a white dwarf. Therefore it seemed to be worth to present an evolutionary scenario from an original binary system which can be applied for all of VSOP binaries.

scholarly journals Binary evolution leading to the formation of the very massive neutron star in the J0740+6620 binary system

2020 ◽  
Vol 495 (2) ◽  
pp. 2509-2514
Author(s):  
M Echeveste ◽  
M L Novarino ◽  
O G Benvenuto ◽  
M A De Vito
Keyword(s):  
Neutron Star ◽  
Binary System ◽  
Effective Temperature ◽  
Binary Systems ◽  
Close Binary ◽  
Normal Donor ◽  
Millisecond Pulsar ◽  
Massive Neutron Star ◽  
Binary Evolution ◽  
Age Of The Universe

ABSTRACT We study the evolution of close binary systems in order to account for the existence of the recently observed binary system containing the most massive millisecond pulsar ever detected, PSR J0740+6620, and its ultra-cool helium white dwarf companion. In order to find a progenitor for this object we compute the evolution of several binary systems composed by a neutron star and a normal donor star employing our stellar code. We assume conservative mass transfer. We also explore the effects of irradiation feedback on the system. We find that irradiated models also provide adequate models for the millisecond pulsar and its companion, so both irradiated and non irradiated systems are good progenitors for PSR J0740+6620. Finally, we obtain a binary system that evolves and accounts for the observational data of the system composed by PSR J0740+6620 (i.e. orbital period, mass, effective temperature and inferred metallicity of the companion, and mass of the neutron star) in a time scale smaller than the age of the Universe. In order to reach an effective temperature as low as observed, the donor star should have an helium envelope as demanded by observations.

scholarly journals On the Binary Nature of the Slow Nova, RR Telescopii

1974 ◽  
Vol 59 ◽  
pp. 123-124
Author(s):  
B. L. Webster
Keyword(s):  
Binary System ◽  
Energy Distribution ◽  
Wavelength Range ◽  
Mass Exchange ◽  
Orbital Period ◽  
Optical Spectrum ◽  
Classical Novae ◽  
Cool Star ◽  
Current Mass ◽  
Orbital Periods

Those novae known to be binaries generally have orbital periods of the order of hours, exceptions being the atypical recurrent novae T CrB and RS Oph, which have giant companions and probably much longer periods. Since the orbital period in a semi-detached system relates to the mechanism of current mass exchange and also to the extent to which the primary evolved before mass exchange took place at an earlier stage, it is of interest to see if any classical novae are in more widely separated systems.This communication concerns the star RR Telescopii, which has all the characteristics of a slow nova – a range in amplitude greater than seven magnitudes, a spectral type at maximum of F, and a decline through a nebular stage of increasing ionization level (e.g. Thackeray, 1955). RR Tel was seen as a variable before outburst, but little is known about this variable apart from its period of 387 days, although doubts have been expressed about its being a red variable (Payne-Gaposchkin, 1957). Dr Thackeray has Radcliffe spectrograms of RR Tel from soon after maximum to the present. On some of the more recent of these, bands of TiO have become visible, presumably as the hot star has faded, and Dr Thackeray and I interpret these as meaning that the original variable is still there and is an M giant. Thus RR Tel is in a binary system containing a giant M star and a hot companion and such a system cannot have an orbital period of hours like the classical novae mentioned above.In 1972, Dr Glass and I examined RR Tel in the infrared between 1.2 and 20 µ. The energy distribution does not resemble the cool star that might be expected, but is exactly like that of free-free radiation over the whole wavelength range. The puzzle is that the infrared is two orders of magnitude stronger than we would predict from the optical spectrum for free-free radiation.

scholarly journals Recycling in progress: RXTE discovery of the first accretion-powered millisecond pulsar

2000 ◽  
Vol 177 ◽  
pp. 643-648
Author(s):  
M. van der Klis
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Binary System ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Radio Pulsar ◽  
Millisecond Pulsar ◽  
X Ray ◽  
Millisecond Radio

AbstractThe discovery is reported of the first accretion-powered millisecond pulsar, SAX J 1808.4–3658. This 2.5 millisecond pulsar has a magnetic field strength of 1–10108Gauss and has all the characteristics of the long-predicted millisecond radio pulsar progenitor, a neutron star in an X-ray binary system where the process of recycling is taking place at this time.

scholarly journals The Evolutionary Status of PSR 1718–19

1996 ◽  
Vol 165 ◽  
pp. 73-79
Author(s):  
Ene Ergma ◽  
Marek J. Sarna
Keyword(s):  
Neutron Star ◽  
Binary System ◽  
Main Sequence ◽  
Roche Lobe ◽  
Evolutionary Status ◽  
Star Model ◽  
Eclipsing Binary ◽  
Matter Source

Possible models for the matter source inside the eclipsing binary system PSR 1718–19, and for the evolution of this system are reviewed, including Zwitter's (1993) stripped main-sequence (MS) turnoff star model. Both the accretion induced collapse (AIC) scenario with a young neutron star, and the capture scenario with an old neutron star are discussed. Although Burderi & King (1994) claim that the size of the Roche lobe (∼0.5 R⊙) unambiguously rules out the AIC formation scenario, we show that in our evolutionary picture an AIC scenario will be possible.

scholarly journals A Shapiro delay detection in the pulsar binary system PSR J1811–2405

2020 ◽  
Vol 493 (1) ◽  
pp. 1261-1267
Author(s):  
C Ng ◽  
L Guillemot ◽  
P C C Freire ◽  
M Kramer ◽  
D J Champion ◽  
...  
Keyword(s):  
Binary System ◽  
Orbital Period ◽  
Binary Systems ◽  
Millisecond Pulsar ◽  
Orbital Inclination ◽  
Compact Binary ◽  
A Value ◽  
Delay Detection ◽  
Pulsar Timing ◽  
Compact Binary Systems

ABSTRACT This paper presents the first detection of Shapiro delay from the binary millisecond pulsar PSR J1811–2405. We report a 11σ measurement of the orthometric amplitude, h3 = 6.8(6) × 10−7, and a 16σ measurement of the orthometric ratio, ς = 0.81(5). Given the relatively high orbital inclination, i = 79(2)°, of this binary system, we obtain constraints on the companion mass of $m_{\rm {c}}=0.31^{+0.08 }_{ -0.06}\, \mathrm{M}_{\odot }$. The pulsar mass is currently less well constrained, with a value of $2.0^{+0.8 }_{ -0.5}\, \mathrm{M}_{\odot }$. The companion mass and the orbital period are in agreement with the prediction made by previous numerical calculations of the evolution of compact binary systems. From a study of the polarization, we find that the orbital inclination angle is ∼100° and that PSR J1811–2405 is an orthogonal rotator. In addition, the μs-level timing precision together with its narrow profile makes PSR J1811–2405 a good candidate for inclusion in the pulsar timing arrays being used to detect nHz gravitational waves.

Long-term optical variability of Her X-1

2018 ◽  
Vol 14 (S346) ◽  
pp. 239-241
Author(s):  
T. İçli ◽  
D. Koçak ◽  
K. Yakut
Keyword(s):  
Neutron Star ◽  
Binary System ◽  
Orbital Period ◽  
Optical Variability ◽  
National Observatory ◽  
Short Term ◽  
X Ray ◽  
Robotic Telescope

AbstractLong-term and short-term multicolor photometric variations of the X-ray binary system Her X-1 (HZ Her) has been studied. We obtained new VRI observations of the system by using the 60cm Robotic telescope at the TÜBİTAK National Observatory (TUG) in 2018. Using newly obtained data, we modified the orbital period of the binary system with a neutron star component.

scholarly journals THE FIRST DETAILED ANALYSIS ON THE ASTROPHYSICAL PROPERTIES OF THE ECCENTRIC BINARY V990 HER

2021 ◽  
Vol 57 (2) ◽  
pp. 363-379
Author(s):  
E. Kiran ◽  
V. Bakiş ◽  
H. Bakiş ◽  
Ö. L. Değirmenci
Keyword(s):  
Binary System ◽  
Detailed Analysis ◽  
Internal Structure ◽  
Orbital Period ◽  
Spectroscopic Data ◽  
Main Sequence ◽  
Physical Parameters ◽  
Apsidal Motion ◽  
Structure Constants ◽  
First Time

We present accurate physical parameters of the eccentric binary system V990 Her which has an orbital period of P=8.193315±0.000003 days using its photometric and spectroscopic data. The physical parameters of the components were derived as Teff1=8000±200 K, Teff2=7570±200 K, M1=2.01±0.07 Mʘ, M2=1.83±0.03 Mʘ, R1=2.22±0.02 Rʘ, R2=2.12±0.01 Rʘ, log(L1/Lʘ)=1.25±0.04, log(L2/Lʘ)=1.12±0.05. Our findings revealed that both components are slightly evolved from the zero-age main sequence with an age of 6.3×108 years. We estimated an apsidal motion with a period of U=14683±2936 years in the system and the internal structure constants of the components were derived for the first time.

scholarly journals A Limit on the Space Density of Short-Period Binary White Dwarfs

1989 ◽  
Vol 114 ◽  
pp. 492-497
Author(s):  
Edward L. Robinson ◽  
Allen W. Shafter
Keyword(s):  
Orbital Period ◽  
Binary Stars ◽  
White Dwarfs ◽  
Main Sequence ◽  
Close Binaries ◽  
Main Sequence Stars ◽  
Space Density ◽  
Short Period ◽  
Hot Subdwarfs ◽  
Orbital Periods

We infer that detached binary white dwarfs with orbital periods of a few hours exist because we observe both their progenitors and their descendents. The binary LB 3459 has an orbital period of 6.3 hr and contains a pair of hot subdwarfs that will eventually cool to become white dwarfs (Kilkenny, Hill, and Penfold 1981). L870-2 is a pair of white dwarfs and, given enough time, its 1.55 d orbital period will decay to shorter periods (Saffer, Liebert, and Olszewski 1988). GP Com, AM CVn, V803 Cen, and PG1346+082 are interacting binary white dwarfs with orbital periods between 1051 s for AM CVn and 46.5 min for GP Com (Nather, Robinson, and Stover 1981; Solheim et al. 1984; Wood et al. 1987; O’Donoghue and Kilkenny 1988). These ultrashort period systems must be descendents of detached pairs of white dwarfs. We also expect short-period binary white dwarfs to exist for theoretical reasons. All calculations of the evolution of binary stars show that main-sequence binaries can evolve to binary white dwarfs (e.g., Iben and Tutukov 1984). Among Population I stars, 1/2 to 2/3 of all main-sequence stars are binaries and about 20% of these binaries should become double white dwarfs with short orbital periods (Abt 1983, Iben and Tutukov 1986). Thus, about 1/10 of all white dwarfs could be close binaries (Paczynski 1985). Nevertheless, no detached binary white dwarfs with extremely short periods have yet been found.

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