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.

scholarly journals Super-Eddington Accretion in the Formation of Low-Mass X-ray Binaries and Millisecond Pulsars

1997 ◽  
Vol 163 ◽  
pp. 828-829 ◽  
Author(s):  
R. F. Webbink ◽  
V. Kalogera
Keyword(s):  
Mass Transfer ◽  
Initial Phase ◽  
Transfer Rate ◽  
Birth Rate ◽  
Mass Transfer Rate ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Low Mass ◽  
Orbital Periods ◽  
X Ray Binaries

AbstractConsiderations of donor star stability, age, and mass transfer rate show that low-mass X-ray binaries and binary millisecond pulsars with orbital periods longer than a few days must have survived an initial phase of super-Eddington mass transfer. We review the physical arguments leading to this conclusion, and examine its implications for the apparent discrepancy between the death rate for low-mass X-ray binaries and the birth rate of binary millisecond pulsars.

scholarly journals A Beat Phenomenon in Dwarf Nova Eruptions

1977 ◽  
Vol 42 ◽  
pp. 227-233
Author(s):  
N. Vogt
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Transfer Rate ◽  
Convection Zone ◽  
Mass Transfer Rate ◽  
Accretion Disc ◽  
Light Curves ◽  
Dwarf Nova ◽  
Beat Phenomenon ◽  
Photoelectric Observations

Photoelectric observations of the dwarf nova VW Hyi, obtained at the end of the December 1975 supermaximum, are presented. After decline from the outburst, the superhump period (0ḍ07622) combines with the orbital period (0ḍ07427) to a beat phenomenon: the O-C’s and the light curves of the orbital hump vary systematically with the phase of the beat period for at least one week after recovery from the supermaximum. It is suggested that the red secondary component, which rotates non-synchroneously with the superhump period, expands slightly at the beginning of a supermaximum and is heated up asymmetrically, probably due to instabilities in its convection zone. In addition, the increased mass transfer rate may trigger the long eruption in the accretion disc while short eruptions originate in the disc without participation of the secondary.

scholarly journals Minimum Orbital Period of Cataclysmic Variables

1979 ◽  
Vol 53 ◽  
pp. 504-504
Author(s):  
B. Paczynski ◽  
W. Krzeminski
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Orbital Period ◽  
Time Scale ◽  
Transfer Rate ◽  
Main Sequence ◽  
Mass Transfer Rate ◽  
Cataclysmic Variables ◽  
Transfer Rates ◽  
Angular Momentum Loss

The shortest known orbital period of a cataclysmic binary with a hydrogen dwarf secondary filling its Roche lobe is about 80 minutes. Theoretically the shortest possible orbital period for such a system is less than 60 minutes. We tried to explain why the periods shorter than 80 minutes are not observed. We estimated the time scale of angular momentum loss of a cataclysmic binary and the resulting mass transfer rate. The minimum orbital period for a given Ṁ is obtained during the transition of the secondary from the Main Sequence onto the Degenerate Dwarf Sequence. Pmin ∝ Ṁ½ Therefore, only those systems can reach low P for which Ṁ is small. This explains why among the shortest period cataclysmic variables there are no novae: presumably their mass transfer rates are too large. It also indicates that “polars” (AM Her-type stars) and SU UMa-type stars should have low Ṁ.

scholarly journals Irregular X-ray Variation of LMC X-3

1995 ◽  
Vol 151 ◽  
pp. 336-337
Author(s):  
H.C. Pan ◽  
G.K. Skinner ◽  
R.A. Sunyaev ◽  
N.L. Alexandrovich
Keyword(s):  
Mass Transfer ◽  
Energy Range ◽  
Spectral Resolution ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Space Station ◽  
Large Magellanic Cloud ◽  
Accretion Disc ◽  
X Ray ◽  
Coded Mask

LMC X-3 is an X-ray binary in the Large Magellanic Cloud. It was discovered by UHURU and observations with various satellites showed that the X-ray source was variable by a factor of up to 100 (e.g. Traves et al. 1988). Using the GINGA and HEAO-1 observations, Cowley et al. (1991) found a strong ∼ 198 (or possibly ∼ 99) day modulation in the X-ray luminosities of LMC X-3. They suggested that this modulation may be due to an accretion disc precession, or periodic variations in the mass transfer rate, or a combination of both.We observed LMC X-3 with the TTM in 1988-1990. The present paper gives some results from the analysis of the data obtained.The TTM is a coded mask telescope on board the MIR space station. It is capable of producing images in the energy range 2-30 keV with a spectral resolution of about 18% at 6 keV (Brinkman et al. 1985).

scholarly journals A Brown Dwarf Companion to the Nova-like Variable RW Tri

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 94
Author(s):  
Zhibin Dai ◽  
Shengbang Qian ◽  
Indika Medagangoda
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Base Line ◽  
Mass Ratio ◽  
Brown Dwarf ◽  
Period Range ◽  
Period Decrease ◽  
Cataclysmic Variable Evolution

The orbital period of Nova-like variable RW Tri is expected to experience a long-term evolution due to a stable mass transfer from the red dwarf to the white dwarf. By adding 297 new eclipse timings obtained from our own observations and a cross-identification of many databases, we fully reinvestigated the variations in orbital period of RW Tri, based on a total of 658 data points spanning over 80 years. The new O-C diagram demonstrates a more complicate pattern than a pure sinusoidal modulation shown in the previous O-C analyses. The best fit of the O-C variations is a quadratic-plus-sinusoidal curve with a period of 22.66 (2) years and a typical decrease rate of P˙ = −2d.32(4) × 10−9 yr−1. To explain secular orbital period decrease, the magnetic braking effect is required to cause the orbital angular moment loss in RW Tri with a mass ratio less than unity, while a conserved mass transfer is also enough for RW Tri with a mass ratio larger than unity. No matter what the mass ratio is, a slightly enhanced mass transfer rate, 2.4–5.3 × 10−9 M⊙ yr−1, derived from our O-C diagram, providing an evidence supporting the disk instability model and the standard/revised models of cataclysmic variable evolution, is almost the same as that obtained from the light-curve modeling. This further confirms our observed orbital period decrease and the controversial system parameter, mass transfer rate. Our updated O-C analysis further verifies the claimed cyclical changes of orbital period with a period range of 21–24 years, which is approximately one half of the results in the literature. In accordance with the light-travel time effect, this periodical variation shown in our new O-C diagram indicates a brown dwarf hidden in RW Tri at a coplanar orbit. Note that the large scatter in the data range of 0–3 × 104 cycles requires the high-precision photometry in the longer base line in the future.

scholarly journals Testing the disk instability model of cataclysmic variables

2018 ◽  
Vol 617 ◽  
pp. A26 ◽  
Author(s):  
Guillaume Dubus ◽  
Magdalena Otulakowska-Hypka ◽  
Jean-Pierre Lasota
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Sampling Rate ◽  
Cataclysmic Variables ◽  
Irregular Sampling ◽  
Light Curves ◽  
Stable Region ◽  
Dwarf Novae

Context. The disk instability model (DIM) attributes the outbursts of dwarf novae to a thermal-viscous instability of their accretion disk, an instability to which nova-like stars are not subject. Aims. We aim to test the fundamental prediction of the DIM: the separation of cataclysmic variables (CVs) into nova-likes and dwarf novae depending on orbital period and mass transfer rate from the companion. Methods. We analyzed the light curves from a sample of ≈130 CVs with a parallax distance in the Gaia DR2 catalog to derive their average mass transfer rate. We validated the method for converting optical magnitude to mass accretion rate against theoretical light curves of dwarf novae. Results. Dwarf novae (resp. nova-likes) are consistently placed in the unstable (resp. stable) region of the orbital period – mass transfer rate plane predicted by the DIM. None of the analyzed systems present a challenge to the model. These results are robust against the possible sources of error and bias that we investigated. Light curves from Kepler or, in the future, the LSST or Plato surveys, could alleviate a major source of uncertainty, that is, the irregular sampling rate of the light curves, assuming good constraints can be set on the orbital parameters of the CVs that they happen to target. Conclusions. The disk instability model remains the solid basis on which to construct an understanding of accretion processes in CVs.

scholarly journals Discless Accretion in Intermediate Polars?

1997 ◽  
Vol 163 ◽  
pp. 420-423
Author(s):  
David A.H. Buckley
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
X Ray ◽  
Spin Period ◽  
Synodic Period ◽  
Intermediate Polars

AbstractI review the evidence for disc and discless accretion in the asynchronous magnetic CVs, the intermediate polars (IPs). The presence and relative amplitudes of the spin and synodic (beat) X-ray periods, and related orbital sidebands, are very model dependent, and support disc accretion dominating in all the well-studied IPs. A component of non-disc accretion is sometimes observed, a result of stream overflow penetrating to the magnetosphere, and is responsible for the synodic period. The recently discovered polarized IP, RX J1712.6–2414, is a prime candidate (the first) for purely discless, stream-fed accretion in such a system. While the polarisation varies at the spin period, the X-ray variations occur at the synodic period, a result of the modulation in the mass transfer rate for a discless accretor.

scholarly journals Orbital Period Modulation in SW Cygni

2007 ◽  
Vol 24 (2) ◽  
pp. 61-68 ◽  
Author(s):  
Davood Manzoori
Keyword(s):  
Mass Transfer ◽  
Fourier Analysis ◽  
Orbital Period ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Period Change ◽  
Rate Of Change ◽  
Relative Mass ◽  
Eclipsing Binary ◽  
Period Variations

AbstractThe O–C curve of the Algol-type eclipsing binary SW Cyg was analyzed using the Kalimeris method. The observed period variations with time, the P(E) function and its rate of change dP/dE, were calculated. The plots of O–C values as well as of P(E) and dP/dE against ephemeris (E) all show rather regular period variations in this system. To reveal any cyclic period variations, the P(E) function was subjected to Fourier analysis. A cyclic period change of average ≈27.8-yr duration was obtained. Also a relative mass transfer rate of Δm/m = −1.1 × 10−9 yr−1 was estimated. Finally the existence of a third companion is suggested, and possible causes of period variations in the system are discussed.

scholarly journals V1082-Sgr: A magnetic cataclysmic variable with a lobe-filling companion star

2019 ◽  
Vol 489 (3) ◽  
pp. 3031-3035
Author(s):  
Xiaojie Xu ◽  
Yong Shao ◽  
Xiang-Dong Li
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Flux Ratio ◽  
Roche Lobe ◽  
High Mass ◽  
Cataclysmic Variable ◽  
X Ray ◽  
V Band ◽  
Sgr A

ABSTRACT V1082 Sgr is a cataclysmic variable with accretion luminosity above 1034 erg s−1, indicating a mass-transfer rate above $10^{-9}\, \mathrm{M}_{\odot }$  yr−1. However, its K-type companion was suggested to be underfilling its Roche lobe (RL), making the high mass-transfer rate a mystery. In this work we propose a possible model to explain this discrepancy. The system is proposed to be an intermediate polar, with its K-type companion filling its RL. The mass of the white dwarf star is evaluated to be $0.77\pm 0.11\, \mathrm{M}_{\odot }$ from both X-ray continuum fitting and Fe line flux ratio measurements. We make numerical simulations to search for the possible progenitors of the system. The results show that a binary with an initial 1.5–2.5$\, \mathrm{M}_{\odot }$ companion in a one to two day orbit (or an initial 1.0–1.4$\, \mathrm{M}_{\odot }$ companion in a 3.2–4.1 d orbit) may naturally evolve to a cataclysmic variable with a $\sim 0.55 \pm 0.11\, \mathrm{M}_{\odot }$, Roche-lobe-filling companion in a 0.86 d orbit. The effective temperature of the donor star, the mass-transfer rate, and the derived V-band magnitude are all consistent with previous observations.

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