BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Quasi-periodic oscillations in black-hole binaries - Sara Motta (U
 niversity of Oxford)
DTSTART:20170123T160000Z
DTEND:20170123T170000Z
UID:TALK69578@talks.cam.ac.uk
CONTACT:Antoine Riols
DESCRIPTION: Fast time variability is an important characteristic of black
  hole X-ray binaries and a key ingredient in understanding the physical pr
 ocesses in these systems. Black hole X-ray binaries show a variety of X-ra
 y spectral/variability states\, representing different accretion regimes a
 nd it has been recently shown that the overall strength of the rapid varia
 bility is a good tracer of these states. \nFast aperiodic variability is g
 enerally studied through the inspection of power density spectra. Most of 
 the power spectral components are broad and can take the form of a wide po
 wer distribution over several decades of frequency or of a more localised 
 peak (quasi-periodic oscillations\, QPOs). \nIt is now clear that QPOs are
  a common characteristic of accreting systems: they have been observed in 
 accreting stellar mass black holes and neutron stars hosted in X-ray binar
 ies\, in cataclysmic variable\, in the so-called ultra luminous X-ray sour
 ces and even in active galactic nuclei. Even though their origin and natur
 e is still debated\, the study of QPOs provides a way to explore the inner
  accretion flow around black holes and neutron stars. Various theoretical 
 models have been proposed to explain the origin of QPOs in black hole bina
 ries\, only a few proved to be promising so far\, having shown good agreem
 ent with observations. I will describe how timing is used in X-rays to pro
 be accretion onto compact objects and how QPOs are usually studied. I will
  briefly review some of the proposed models and I will finally show the mo
 st recent results obtained on QPOs. \n\n
LOCATION:MR14\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
END:VEVENT
END:VCALENDAR