A flickering study of nova-like systems KR Aur and UU Aqr

Dobrotka, A.; Mineshige, S.; Casares, J.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society, Volume 420, Issue 3, pp. 2467-2474.

Fecha de publicación:
3
2012
Número de autores
3
Número de autores del IAC
1
Número de citas
12
Número de citas referidas
11
Descripción
We present a study of the flickering activity in two nova-like systems, KR Aur and UU Aqr. We applied a statistical model of flickering simulations in accretion discs based on turbulent angular momentum transport between two adjacent rings with an exponential distribution of the turbulence dimension scale. The model is based on a steady-state disc model, which is satisfied in the case of hot ionized discs of nova-like cataclysmic variables. Our model successfully fits the observed power-density spectrum of KR Aur with the disc parameter α= 0.10-0.40 and an inner-disc truncation radius in the range Rin= 0.88-1.67 × 109 cm. The exact values depend on the mass-transfer rate in the sense that α decreases and Rin increases with mass-transfer rate. In any case, the inner-disc radius found for KR Aur is considerably smaller than those for quiescent dwarf novae, as predicted by the disc instability model. On the other hand, our simulations fail to reproduce the power-density spectrum of UU Aqr. A tantalizing explanation involves the possible presence of spiral waves, which are expected in UU Aqr because of its low mass ratio but not in KR Aur. In general our model predicts the observed concentration of flickering in the central disc. We explain this by the radial dependence of the angular-momentum gradient.
Proyectos relacionados
Representación de la variable cataclísmica SS Cygni (Chris Moran)
Estrellas Binarias
El estudio de las estrellas binarias es una parte esencial de la astrofísica estelar. Una gran parte de las estrellas de nuestra Galaxia y de otras galaxias se ha formado en sistemas binarios o múltiples, por lo que entender la estructura y evolución de estos sistemas es importante desde el punto de vista estelar y galáctico. Un aspecto en el que
Pablo
Rodríguez Gil