Apr 25 – 29, 2016
Istanbul
Europe/Istanbul timezone

Accretion in white dwarf binaries - short time variability and broadband noise characteristics: connecting CVs to neutron star and black hole binaries

Apr 26, 2016, 2:20 PM
20m
Bogazici University-Rectorate Building (Istanbul)

Bogazici University-Rectorate Building

Istanbul

Boğaziçi University 34342 Bebek/Istanbul Turkey

Speaker

Prof. Şolen Balman

Description

I review accretion in Cataclysmic Variable systems with emphasis on flicker
noise and its variations that have been a diagnostic tool in understanding the structure in accretion disks.
I study the nature of time variability of brightness of non-magnetic
cataclysmic variables. Dwarf novae demonstrate band limited noise in the UV and X-ray energy bands, which can be adequately explained
in the framework of the model of propagating fluctuations as in XRBs. The detected frequency breaks in the range (1-6) mHz indicates
an optically thick disk truncation in the inner disk of some dwarf novae systems in quiescence.
Analysis of other available data (SS Cyg, SU UMa, WZ Sge, Z Cha) indicate that during the outburst the inner
disk radius moves towards the white dwarf and recedes as the outburst declines while changes in the X-ray energy
spectrum is also observed. Cross-correlations between the simultaneous
Optical, UV and X-ray light curves show time lags in the X-rays (90-180 sec) consistent with truncated inner optically thick disk.
I compare magnetic and nonmagnetic CVs in terms of their broadband noise characteristics
which in general show compliance with the model of propagating fluctuations.
In addition, I discuss comparisons with X-ray binaries.

Primary author

Presentation materials