The dwarf nova V1239 herculis in quiescence

Khruzina, T. S.; Golysheva, P.; Katysheva, N. A.; Shugarov, S. Yu.; Шакура, Н. И.

doi:10.1134/s1063772915040034

Cited by 14 publications

(18 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These circumstances force the necessity to take into account possible existence of spots on the surfaces of tidally de-formed optical stars (as well as existence of an accretion disc with its interaction region with the gas stream) while interpreting the optical and IR light curves of LMXRBs. This was firstly performed in the work of Khruzina & Cherepashchuk (1995) for interpretation of long-term orbital curves variability of the X-ray nova A0620-00 where it was shown that such a curves variation may be reconstructed by appearance, motion and dissolving of "dark" spots on the stellar surface. One of the goals of the current paper is indeed the account for spot structures of A0620-00 on the base of an advanced LMXRB system model (see, e.g.…”

Section: System Descriptionmentioning

confidence: 99%

See 1 more Smart Citation

Optical andJ, K-photometry of the quiescent black hole X-ray nova A0620−00 in the passive and active states

Черепащук

Katysheva

Khruzina

et al. 2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Photometric observations of the low-mass X-ray binary system A0620-00=V616 Mon are performed in the optical (unfiltered light, λ eff ≈ 6400Å) and the near-infrared J and K-bands. The mean system flux, the orbital light curve shape and the flickering amplitude dependences on wavelength are examined in the λλ6400 − 22000Å range for two activity stages of the system which remains in quiescence.In 2015-16 the A0620-00 system was observed to be in passive stage (according to the terminology of Cantrell et al., 2008) exhibiting the regular orbital light curve with a relatively low flickering level.In less than 230 days in 2016-17 the system switched into active stage: its mean brightness increased by ∼ 0.2 − 0.3 mag in all the studied bands, the orbital light curve experienced drastic changes while the flickering amplitude increased more than twice both in the optical and in the infrared.The regular orbital light curves of A0620-00 were modelled within two frameworks, namely assuming existence of "cold" spots on the optical companion surface and without those. These models allow for a good fit of observed orbital light curves both in passive and in active stages. A close correlation between the luminosity of accretion disc, "hotline" and the flickering amplitude is established.The absolute fluxes having been calibrated and corrected for the interstellar extinction, the dependence of the mean square flickering amplitude (in fluxes) is computed as a function of wavelength in the λλ6400 − 22000Å range.In active stage, the observed flickering amplitude decreases as a function of wavelength over the whole studied range and may be adequately represented by a single dependence ∆F fl ∼ λ −2 which corresponds to the thermal free-free emission of optically thin high-temperature plasma.In passive stage, the ∆F fl value behaves like ∆F fl ∼ λ −4 in the short wavelength range of λλ6400 − 12500Å that corresponds to the thermal radiation of optically thick high-temperature plasma. In the long-wave domain λλ12500 − 22000Å the flickering amplitude dependence is flat: ∆F fl ∼ const which may imply existence of a synchrotron component of the relativistic jets emission.The ∆F fl dependence on the mean system flux in K-filter is shallower than corresponding relations for the filter J and for the optical range.The above mentioned flickering features let us propose that the mechanism responsible for flickering includes at least two components: thermal and, apparently, synchrotron, that agrees with the recent discovery of the variable linear polarization of the infrared system emission (Russell et al., 2016).

show abstract

Section: System Descriptionmentioning

confidence: 99%

“…This pattern may be further complicated by effects of the optical star physical variability and modulated by spot structures on its surface (see e.g. Khruzina & Cherepashchuk 1995;Zurita et al 2016).…”

mentioning

confidence: 99%

Optical andJ, K-photometry of the quiescent black hole X-ray nova A0620−00 in the passive and active states

Черепащук

Katysheva

Khruzina

et al. 2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…The mathematical model includes the set of hydrodynamic equations of ideal (inviscid) partially ionized hydrogen gas with account Khruzina et al (2015).…”

Section: Equations and Notationsmentioning

confidence: 99%

3D modelling of accretion disc in eclipsing binary system V1239 Her

Lukin

Malanchev

Шакура

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We present the results of 3D-hydrodynamical simulations of accretion flow in the eclipsing dwarf nova V1239 Her in quiescence. The model includes the optical star filling its Roche lobe, a gas stream emanating from the inner Lagrangian point of the binary system, and the accretion disc structure. A cold hydrogen gas stream is initially emitted towards a point-like gravitational centre. A stationary accretion disc is formed in about 15 orbital periods after the beginning of accretion. The model takes into account partial ionization of hydrogen and uses realistic cooling function for hydrogen. The light curve of the system is calculated as the volume emission of optically thin layers along the line of sight up to the optical depth τ = 2/3 calculated using Planck-averaged opacities. The calculated eclipse light curves show good agreement with observations, with the changing shape of pre-eclipse and post-eclipse light curves being explained entirely due to ∼ 50% variations in the mass accretion rate through the gas stream.

show abstract

“…By detecting variations in the mid-eclipse times, substellar objects have been suggested to exist in several DN (e.g., V2051 Oph (Qian et al 2015) and EM Cyg (Dai & Qian 2010)). In addition, many synthetic light curve analysis methods (e.g., BINSYN program (Linnell et al 2012), Eclipsing Light Curve Code (Orosz & Hauschildt 2000) and the cool-disk model (Khruzina 2011)) have been developed to analyze CV eclipse light curves. The irregular eclipse light curves of quiescent CVs are composed of the occultations of multiple components including the white dwarf, the accretion disk and hotspots (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the majority of CVs have only low time-resolution photometry comprised of blended flux from many components, which makes modelling these systems difficult. For example, recent discussions concerning two new-found CVs with deep eclipses carried out by Kjurkchieva et al (2015) and Kennedy et al (2016) clearly indicated that the model light curves cannot perfectly fit the observed eclipsing light curves during ingress and outside of eclipse. Assuming a deep eclipse is a common feature of CVs with orbital inclination higher than 80 • , the fraction of low-inclination CVs can be simply estimated to be around 90%.…”

Section: Introductionmentioning

confidence: 99%

A Phenomenological Model for the Light Curve of Three Quiescent Low-inclination Dwarf Novae and One Pre-cataclysmic Variable

Dai

Szkody

Kennedy

et al. 2018

View full text Add to dashboard Cite

We used the light curve code XRBinary to model the quiescent K2 light curves of three low-inclination cataclysmic variables (CVs): 1RXS J0632+2536 (J0632+2536), RZ Leo, TW Vir and the pre-CV WD 1144+011. Optimized light curve models were obtained using a nonlinear fitting code NMfit and visualized by Phoebe 2.0. The disk model of J0632+2536 shows that one hotspot at the edge of the disk is enough to describe its light curve, while the other two dwarf nova (DN): RZ Leo and TW Vir require two hotspots. A typical pre-CV model with a weak irradiation effect for WD 1144+011 can explain its single-hump modulation, and the newly observed spectrum confirms its previous classification. The synthetic analyses for the DN clearly indicate that phase zero of the double-hump modulations occurs around the secondary minimum and the primary hump is mainly caused by the hotspot at the edge of the disk. The quiescent disk has a flat temperature distribution with a power index of ∼ 0.11. The disk model of RZ Leo implies a truncated disk, supporting its previously speculated classification as an intermediate polar (IP). Except for the IP model of RZ Leo, which lacks a component related to the inferred accretion curtain, the models of J0632+2536, TW Vir and WD 1144+011 are consistent with results from the Gaia mission. TheCorresponding author: Zhibin Dai zhibin dai@ynao.ac.cn arXiv:1808.06174v1 [astro-ph.SR] 19 Aug 2018 2 derived masses and radii of the secondaries of the three DN are consistent with the semiempirical relations for CV donor stars, while their effective temperatures are higher than the predictions. Irradiation of the donor stars is investigated to explain this discrepancy.

show abstract

The dwarf nova V1239 herculis in quiescence

Cited by 14 publications

References 16 publications

Optical andJ, K-photometry of the quiescent black hole X-ray nova A0620−00 in the passive and active states

Optical andJ, K-photometry of the quiescent black hole X-ray nova A0620−00 in the passive and active states

3D modelling of accretion disc in eclipsing binary system V1239 Her

A Phenomenological Model for the Light Curve of Three Quiescent Low-inclination Dwarf Novae and One Pre-cataclysmic Variable

Contact Info

Product

Resources

About