The period bouncer system SDSS J105754.25+275947.5: first radial velocity study

Abstract

We report the first radial velocity spectroscopic study of the eclipsing period bouncer SDSS J105754.25+275947.5. Together with eclipse light curve modeling, we redetermined the system parameters and studied the accretion disk structure. We confirm that the system contains a white dwarf with $M_{\mathrm{WD}}=0.83(3)M_{\odot }$ and an effective temperature of 11,500(400)K. The mass of the secondary is $M_2=0.056M_{\odot }$ with an effective temperature of T${}_2$=2,100K or below. The system inclination is $i=84.3(6)$. The data is in good agreement with our determination of $K_1$ = 33(4) km s${}^{-1}$. We estimate the mass transfer rate as $\dot{M}=$1.9(2)$\times 10^{-11}{M}_{\odot }y{r}^{-1}$. Based on an analysis of the SDSS and OSIRIS spectra, we conclude that the optical continuum is formed predominantly by the radiation from the white dwarf. The contribution of the accretion disk is low and originates from the outer part of the disk. The Balmer emission lines are formed in a plasma with $\log$ $N_0$ = 12.7 [cm${}^{-1}$] and a kinetic temperature of T$\sim$10,000K. The size of the disk, where the emission lines are formed, expands up to $R_{\mathrm{d},\mathrm{out}}=0.29R_{\odot }$. The inner part of the emission line forming region goes down to $R_{\mathrm{d},\mathrm{in}}\approx 2R_{\mathrm{WD}}$ . The Doppler tomography and trailed spectra show the presence of a hot spot and a clumpy structure in the disk, with variable intensity along the disk position angle. There is an extended region at the side opposite the hot spot with two bright clumps caused more probably by non-Keplerian motion there.

8 pages, 9 figures, accepted for publication in MNRAS

References in corpus (7)

• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• Cataclysmic Variables from SDSS VII. The Seventh Year (2006)
• SDSS J105754.25+275947.5: a period-bounce eclipsing cataclysmic variable with the lowest-mass donor yet measured
• Structure of accretion flows in the nova-like cataclysmic variable RW Tri
• Orbital periods of cataclysmic variables identified by the SDSS. IX. NTT photometry of eight eclipsing and three magnetic systems
• The period-gap cataclysmic variable CzeV404 Her: A link between SW Sex and SU UMa systems
• New radial velocity observations of AH Her: evidence for material outside the tidal radius

Cited by in corpus (1)

• Cataclysmic variables around the period-bounce: An eROSITA-enhanced multi-wavelength catalog