相关论文: Spiral structure in the accretion disc of the bina…

I review the observational evidence for spiral structure in the accretion discs of cataclysmic variables (CVs). Doppler tomography is ideally suited to resolve and map such co-rotating patterns and allows a straightforward comparison with…

We present spectroscopy of the dwarf nova IP Pegasi taken during two consecutive nights, 5 and 6 days after the start of an outburst. Even this late in the outburst, Doppler maps show marked spiral structure in the accretion disc, at least…

The first convincing piece of evidence of spiral structure in the accretion disc in IP Pegasi was found by Steeghs et al. (1997). We performed two kinds of 2D hydrodynamic simulations, a SFS finite volume scheme and a SPH scheme, with a…

We consider the implications of the detection of spiral structure in the accretion disc of the binary IP Pegasi. We use numerical simulations of the development of a disc outburst to construct predicted Doppler tomograms, which are found to…

We perform 2D and 3D numerical simulations of an accretion disc in a close binary system using the Simplified Flux vector Splitting (SFS) finite volume method. In our calculations, gas is assumed to be the ideal one, and we calculate the…

We use the grid of hydrodynamic accretion disc calculations of Stehle (1999) to construct orbital phase dependent emission line profiles of thin discs carrying spiral density waves. The observational signatures of spiral waves are explored…

We present the results of spectral investigations of the cataclysmic variable IP Peg in quiescence. Optical spectra obtained on the 6-m telescope at the Special Astrophysical Observatory (Russia), and on the 3.5-m telescope at the…

In response to our recent discovery of spiral arms in the accretion disc of IP Peg during rise to outburst, we have obtained time-resolved spectrophotometry of IP Peg during outburst maximum. In particular, indirect imaging of HeII 4686,…

IP Pegasi is an eclipsing dwarf nova lying above the period gap with an orbital period of 3.8h. It is the first cataclysmic variable to show evidence of spiral arms in its accretion disc. We present new time-resolved echelle spectroscopic…

We report the analysis of time-resolved spectroscopy of IP Pegasi in outburst with eclipse mapping techniques to investigate the location and geometry of the observed spiral structures. We were able to obtain an improved view of the spiral…

Eclipse lightcurves of the dwarf nova IP Peg during the November 1996 outburst are analysed with eclipse mapping techniques to constrain the location and investigate the spatial structure of the spiral shocks observed in the Doppler…

We present the results of the spectral investigations of IP Peg in quiescence. Optical spectra obtained on 6-m telescope at the Special Astrophysical Observatory (Russia), and on the 3.5-m telescope at the German-Spanish Astronomical Center…

The history of hydrodynamic numerical simulations for accretion disks in close binary systems is reviewed, in which emphasis is placed, in particular, on the facts that spiral shock waves were numerically found in 1986 by researchers…

Observations at high spectral and temporal resolution are presented of the dwarf nova EX Dra in outburst. The disk seen in the He I line reconstructed by Doppler tomography shows a clear two-armed spiral pattern pointing to spiral shocks in…

We present synthetic Doppler maps of gaseous flows in binary IP Peg based on the results of 3D gasdynamical simulations. Using of gasdynamical calculations alongside with the Doppler tomography technique permits us to identify the main…

We present the capabilities of our new code for obtaining Doppler maps implementing the maximum likelihood approach. As test data, we used observations of the dwarf nova V2051 Ophiuchi. The system was observed in quiescence at least 16 d…

We perform simulations in order to reveal the effect of observational and physical parameters on the reconstruction of a spiral structure in an accretion disk, using eclipse mapping techniques. We show that a model spiral structure is…

(abridged) We report eclipse mapping of time resolved spectroscopy of the dwarf nova IP Pegasi on the late decline from the May 1993 outburst. The spiral arms are still visible some 8 days after the onset of the outburst. Their fractional…

The non-axisymmetric features observed in the discs of dwarf novae in outburst are usually considered to be spiral shocks, which are the non-linear relatives of tidally excited waves. This interpretation suffers from a number of problems.…

We present time resolved K-band infrared spectra of the dwarf nova (DN) IP Peg in early quiescence. The Brackett-gamma and HeI lines in our data show hitherto unseen behaviour, which we term a mirror eclipse, and interpret as an eclipse of…