scholarly journals The binary evolution of SAX J1808.4−3658: implications of an evolved donor star

2020 ◽  
Vol 495 (1) ◽  
pp. 796-805
Author(s):  
A J Goodwin ◽  
T E Woods
Keyword(s):  
Mass Transfer ◽  
Binary System ◽  
Orbital Period ◽  
Lagrangian Point ◽  
Millisecond Pulsar ◽  
Pulsar Radiation ◽  
Evolutionary Studies ◽  
Period Derivative ◽  
Binary Evolution ◽  
Additional Loss

ABSTRACT Observations of the accretion powered millisecond pulsar SAX J1808.4−3658 have revealed an interesting binary evolution, with the orbit of the system expanding at an accelerated rate. We use the recent finding that the accreted fuel in SAX J1808.4−3658 is hydrogen depleted to greatly refine models of the progenitor and prior evolution of the binary system. We constrain the initial mass of the companion star to 1.0–1.2 M⊙, more massive than previous evolutionary studies of this system have assumed. We also infer the system must have undergone strongly non-conservative mass transfer in order to explain the observed orbital period changes. We include mass loss due to the pulsar radiation pressure on the donor star, inducing an evaporative wind which is ejected at the inner Lagrangian point of the binary system. The resulting additional loss of angular momentum resolves the discrepancy between conservative mass transfer models and the observed orbital period derivative of this system. We also include a treatment of donor irradiation due to the accretion luminosity, and find this has a non-negligible effect on the evolution of the system.

scholarly journals Rapid orbital expansion in millisecond pulsar PSR J0636+5128: evaporation winds?

2020 ◽  
Vol 501 (2) ◽  
pp. 2327-2331
Author(s):  
Wen-Cong Chen
Keyword(s):  
Orbital Period ◽  
Accretion Disc ◽  
Lagrangian Point ◽  
Millisecond Pulsar ◽  
The Third ◽  
Binary Pulsars ◽  
Period Derivative

ABSTRACT PSR J0636+5128 is a 2.87 ms binary millisecond pulsar (MSP) discovered by the Green Bank Northern Celestial Cap Pulsar Survey, and possesses the third shortest orbital period ( P = 1.6 h) among confirmed binary pulsars. Recent observations reported that this source is experiencing a rapid orbital expansion at a rate of $\dot{P}=(1.89\pm 0.05)\times 10^{-12}\,\rm s\, s^{-1}$. The evaporation winds of the companion induced by the spin-down luminosity of the MSP may be responsible for such a positive orbital period derivative. However, our calculations show that the winds ejecting from the vicinity of the companion or the inner Lagrangian point cannot account for the observation due to an implausible evaporation efficiency. Assuming that the evaporation winds eject from the vicinity of the MSP in the form of asymmetric disc winds or outflows, the evaporation efficiency can be constrained to be ∼0.1. Therefore, the rapid orbital expansion detected in PSR J0636+5128 provides evidence of outflows and accretion disc around the MSP.

scholarly journals Prospects for the Discovery of Black Hole Binaries without Mass Accretion with Gaia

2016 ◽  
Vol 12 (S324) ◽  
pp. 41-42
Author(s):  
Norita Kawanaka ◽  
Masaki Yamaguchi ◽  
Tsvi Piran ◽  
Tomasz Bulik
Keyword(s):  
Mass Transfer ◽  
Black Holes ◽  
Black Hole ◽  
Orbital Period ◽  
Proper Motion ◽  
Binary Systems ◽  
Evolution Model ◽  
Black Hole Binaries ◽  
Black Hole Binary ◽  
Binary Evolution

AbstractWe study the prospect for Gaia to detect black hole binary systems without the mass transfer from their companion stars. Gaia will be able to discover Galactic black holes without mass accretion by detecting the proper motion of their companion stars. We evaluate the number of such black hole binaries which have the orbital period short enough to be detected by Gaia during its operation, taking into account the binary evolution model.

scholarly journals Contamination of RR Lyrae stars from Binary Evolution Pulsators

2015 ◽  
Vol 5 (1) ◽  
pp. 24-28
Author(s):  
P. Karczmarek
Keyword(s):  
Mass Transfer ◽  
Binary System ◽  
Synthesis Method ◽  
Population Synthesis ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Low Mass ◽  
Binary Evolution ◽  
Lyrae Stars ◽  
Range Of Values

A Binary Evolution Pulsator (BEP) is a low-mass (0.26 𝔐☉) member of a binary system, which pulsates as a result of a former mass transfer to its companion. The BEP mimics RR Lyrae-type pulsations, but has completely different internal structure and evolution history. Although there is only one known BEP (OGLE-BLG-RRLYR-02792), it has been estimated that approximately 0.2% of objects classified as RR Lyrae stars can be undetected Binary Evolution Pulsators. In the present work, this contamination value is re-evaluated using the population synthesis method. The output falls inside a range of values dependent on tuning the parameters in the StarTrack code, and varies from 0.06% to 0.43%.

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 Influence of the initial orbital period and accretion efficiency on the low-mass binary evolution

2021 ◽  
pp. 25-30
Author(s):  
J. Petrovic
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
White Dwarf ◽  
Binary Systems ◽  
Evolutionary Models ◽  
Stable Case ◽  
Long Period ◽  
Low Mass ◽  
Orbital Periods ◽  
Binary Evolution

This paper presents detailed evolutionary models of low-mass binary systems (1.25 + 1 M?) with initial orbital periods of 10, 50 and 100 days and accretion efficiency of 10%, 20%, 50%, and a conservative assumption. All models are calculated with the MESA (Modules for Experiments in Stellar Astrophysics) evolutionary code. We show that such binary systems can evolve via a stable Case B mass transfer into long period helium white dwarf systems.

scholarly journals A tidally tilted sectoral dipole pulsation mode in the eclipsing binary TIC 63328020

2021 ◽  
Author(s):  
S A Rappaport ◽  
D W Kurtz ◽  
G Handler ◽  
D Jones ◽  
L A Nelson ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Mode Frequency ◽  
Prior History ◽  
Dipole Mode ◽  
Eclipsing Binary ◽  
Pulsation Mode ◽  
The Third ◽  
History Of ◽  
Binary Evolution

Abstract We report the discovery of the third tidally tilted pulsator, TIC 63328020. Observations with the TESS satellite reveal binary eclipses with an orbital period of 1.1057 d, and δ Scuti-type pulsations with a mode frequency of 21.09533 d−1. This pulsation exhibits a septuplet of orbital sidelobes as well as a harmonic quintuplet. Using the oblique pulsator model, the primary oscillation is identified as a sectoral dipole mode with l = 1, |m| = 1. We find the pulsating star to have M1 ≃ 2.5 M⊙, R1 ≃ 3 R⊙, and Teff, 1 ≃ 8000 K, while the secondary has M2 ≃ 1.1 M⊙, R2 ≃ 2 R⊙, and Teff, 2 ≃ 5600 K. Both stars appear to be close to filling their respective Roche lobes. The properties of this binary as well as the tidally tilted pulsations differ from the previous two tidally tilted pulsators, HD74423 and CO Cam, in important ways. We also study the prior history of this system with binary evolution models and conclude that extensive mass transfer has occurred from the current secondary to the primary.

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.

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 Fun for Two

2001 ◽  
Vol 200 ◽  
pp. 505-510 ◽  
Author(s):  
Simon F. Portegies Zwart ◽  
Lev R. Yungelson ◽  
Gijs Nelemans
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Binary System ◽  
Binary Systems ◽  
Companion Star ◽  
Binary Evolution ◽  
Galactic Astronomy

We performed populations synthesis calculations of single stars and binaries and show that binary evolution is extremely important for Galactic astronomy. We review several binary evolution models and conclude that they give quite different results. These differences can be understood from the assumptions related to how mass is transfered in the binary systems. Most important are 1) the fraction of mass that is accreted by the companion star during mass transfer, 2) the amount of specific angular momentum which is carried away with the mass that leaves the binary system.

scholarly journals Updated orbital ephemeris of the ADC source X 1822-371: a stable orbital expansion over 40 years

2019 ◽  
Vol 625 ◽  
pp. L12 ◽  
Author(s):  
S. M. Mazzola ◽  
R. Iaria ◽  
T. Di Salvo ◽  
A. F. Gambino ◽  
A. Marino ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Optical Data ◽  
Quadratic Model ◽  
Arrival Times ◽  
Companion Star ◽  
X Ray ◽  
Period Derivative

Aims. Source X 1822-371 is an eclipsing compact binary system with a period close to 5.57 h and an orbital period derivative Ṗorb of 1.51(7)×10−10 s s−1. The very high value of Ṗorb is compatible with a super-Eddington mass transfer rate from the companion star, as suggested by X-ray and optical data. The XMM-Newton observation taken in 2017 allows us to update the orbital ephemeris and verify whether the orbital period derivative has been stable over the past 40 yr. Methods. We added two new values obtained from the Rossi-XTE (RXTE) and XMM-Newton observations performed in 2011 and 2017, respectively, to the X-ray eclipse arrival times from 1977 to 2008. We estimated the number of orbital cycles and the delays of our eclipse arrival times spanning 40 yr, using as reference time the eclipse arrival time obtained from the RXTE observation taken in 1996. Results. Fitting the delays with a quadratic model, we found an orbital period Porb = 5.57062957(20) h and a Ṗorb value of 1.475(54)×10−10 s s−1. The addition of a cubic term to the model does not significantly improve the fit quality. We also determined a spin-period value of Pspin = 0.5915669(4) s and its first derivative Ṗspin = − 2.595(11) × 10−12 s s−1. Conclusions. Our results confirm the scenario of a super-Eddington mass transfer rate; we also exclude a gravitational coupling between the orbit and the change in the oblateness of the companion star triggered by the nuclear luminosity of the companion star.

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