Related papers: SPH Simulations of Negative (Nodal) Superhumps: A …
Negative superhumps are believed to arise in cataclysmic variable systems when the accretion disk is tilted with respect to the orbital plane. Slow retrograde precession of the line-of-nodes results in a signal---the negative…
Negative superhumps are photometric modulations in cataclysmic variables with periods slightly shorter than the orbital period. They are usually attributed to retrograde nodal precession of a tilted accretion disk, although the origin and…
In recent years a handful of systems have been observed to show "negative" (nodal) superhumps, with periods slightly shorter than the orbital period. It has been suggested that these modes are a consequence of the slow retrograde precession…
Accretion disks around black hole, neutron star, and white dwarf systems are thought to sometimes tilt, retrogradely precess, and produce hump-shaped modulations in light curves that have a period shorter than the orbital period. Although…
Using smoothed particle hydrodynamics, we numerically simulate steady state accretion discs for Cataclysmic Variable Dwarf Novae systems that have a secondary-to-primary mass ratio (0.35 \le q \le 0.55). After these accretion discs have…
(Abridged) We use 3D SPH calculations with higher resolution, as well as with more realistic viscosity and sound-speed prescriptions than previous work to examine the eccentric instability which underlies the superhump phenomenon in…
We present three dimensional smoothed particle hydrodynamics (SPH) calculations of warped accretion discs in X-ray binary systems. Geometrically thin, optically thick accretion discs are illuminated by a central radiation source. This…
We numerically study the precessing disk model for superhump in the SU~UMa subclass of cataclysmic variables, using a two dimensional SPH code specifically designed for thin disk problems. Two disk simulations for a binary with mass ratio…
We investigate the growth of tidal instabilities in accretion discs in a binary star potential, using three dimensional numerical simulations. As expected from analytic work, the disc is prone to an eccentric instability provided that it is…
In Montgomery (2009a), we show that accretion discs in binary systems could retrogradely precess by tidal torques like the Moon and the Sun on a tilted, spinning, non-spherical Earth. In addition, we show that the state of matter and the…
We propose a mechanism for the superhump modulations observed in optical photometry of at least two black hole X-ray transients (SXTs). As in extreme mass-ratio cataclysmic variables (CVs), superhumps are assumed to result from the presence…
Two dimensional SPH simulations of a precessing accretion disc in a q=0.1 binary system (such as XTE J1118+480) reveal complex and continuously varying shape, kinematics, and dissipation. The stream-disc impact region and disc spiral…
We consider a mechanism for the formation of superhumps in the TV Col system, based on the possible existence of a precessional spiral wave in the accretion disk of the system. This mechanism can act in binaries with arbitrary…
We demonstrate that measurable vertical structure can be excited in the accretion disc of a close binary system by a dipolar magnetic field centred on the secondary star. We present the first high resolution hydrodynamic simulations to show…
We review the theory and observations related to the ``superhump'' precession of eccentric accretion discs in close binary sytems. We agree with earlier work, although for different reasons, that the discrepancy between observation and…
The origin of tilted disks in cataclysmic variables is explained in terms of a model involving the stream-disk interactions. Tilted, precessing disk causes periodically variable asymmetry in the irradiation of the two hemispheres of the…
Since the discovery of superhumps in 1974, these photometric modulations have provided a crucial observational window into disk instabilities in cataclysmic variable stars, particularly the tidal instability associated with the 3:1…
We numerically study the tidal instability of accretion discs in close binary systems using a two-dimensional SPH code. We find that the precession rate of tidally unstable, eccentric discs does not only depend upon the binary mass ratio q.…
Tilted disk precession exists in different objects. Negative superhumps (NSHs) in cataclysmic variable stars (CVs) are believed to arise from the interaction between the reverse precession of a tilted disk and the streams from the secondary…
We present a detailed photometric study of the bright cataclysmic variable BG Tri using ground-based observations mainly from Rozhen Observatory, ASAS-SN, TESS, and WASP sky surveys. We report the discovery of a negative superhump with…