Space Research and Technology Institute, Sofia, Bulgaria X Serbian-Bulgarian Astronomical Conference (X SBAC): 30 May – 03 June 2016, Belgrade, Serbia Emission Properties of White Dwarf’s Accreting Binaries By The Polarization Methods Daniela Boneva Space Research and Technology Institute, Sofia, Bulgaria

Model of the flare activity Indications of active states Outline Aim: Investigation of the relationship between the flare-ups activity in white dwarf binaries and the polarization state. Objects Model of the flare activity Indications of active states Polarization methods and model Analysis of the preliminary results What’s next… X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Objects L1 M1 M2 CVs stars: SS Cyg and V592 Cas StarLightPro-2 simulation CVs stars: SS Cyg and V592 Cas X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Model of bursts and flare-ups activities (Kononov et al. 2008, Boneva et al. 2009) Mass transfer and disturbances in the disc’s flow stronger emission during the development of the outburst Flow transformations, wave pattern formation Gas is leaving the toroidal shell; it forms an expanding spherical shell around the accretor angular momentum transportation efficiency raise; accretion rate onto the binary increases strong heating of the gas between the toroidal shell and the accretor growing intensity of the white dwarf radiation a toroidal shell (C) forms around the accretor (A) heating of the nearest parts of accretion disc growth of the inner parts thickness

Indications of Flare-ups; bursts SS Cyg: Semidetached binary: red dwarf ~ 0.56 Mo and white dwarf ~ 0.97 Mo SS Cyg light curve AAVSO light curve indicates activity Hγ Doppler tomograms for SS Cyg in its active state from spectral observations of this star (Boneva et al. 2009). X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Swift-XRT Energy spectrum, PC mode Indications of Flare-ups; bursts Swift-XRT Energy spectrum, PC mode Swift-XRT light curve of SS Cyg (Swift-XRT generator) X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Indications of Flare-ups; bursts V592 Cas: Cataclysmic variable; white dwarf ~ 0.75 Mo Mac.r. ~ 1×10^−8 M⊙ yr ^−1 Swift-XRT Energy spectrum, PC mode AAVSO light curve of V592 Cas X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

A Schematic view of the polarization modeling: flares to polarization Algorithm of the processes Stages of calculation Bursts; Flare-ups Flare-ups dramatic flux and polarization variations in the optical, near-infrared and X-Ray bands Measurement of the emission intensity Stokes parameters measurement Variations in the flow density level the polarization degree increasing significantly Degree of polarization Type of polarization

Four Stokes parameters Degree of polarization P Degree of circular polarization PC The Poincare vector of polarization …and on the base of models: (Churazov et al. 2002), (Marin et al. 2014) and (Molinary et al. 2011) …. X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Polarization degree (P) during the bursts activity of SS Cyg. P=1 – fully polarized X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Polarization degree (P) during the bursts activity of V592 Cas. P=1 – fully polarized X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

Under Discussion; remarks Pmax depends on the number of dust grains along the line of sight to the star the state of polarization of the emitted light in general provides information on various spatial anisotropies of the excited system polarization parameters could give us information about the basic properties and structures of the flares material degree of polarization depends on the inclination of the disc, and the wavelength dependence of polarization gives information on the size of the scatterers X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

To develop and improve the model; …to be continued Future work: To develop and improve the model; To define the properties and structures of flares; Is it possible to detect the mechanisms that could trigger bursts by the methods of polarimetry? To receive more real data; X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia

THANK YOU!  Acknowledgments: X SBAC Organizing committee This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. Thank the AAVSO (American Association of Variable Star Observers) to provide the data of Light Curve Generator. X Serbian-Bulgarian Astronomical Conference (X SBAC): 30. May – 03. June 2016, Belgrade, Serbia