Phase lags of quasi-periodic oscillations across source states in the low-mass X-ray binary 4U 1636-53

Author(s)

de Avellar, Marcio G. B. ; Mendez, Mariano ; Altamirano, Diego ; Sanna, Andrea ; Zhang, Guobao

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 461, n. 1, p. 79-92, SEP 1 2016.
• Web of Science Citations: 7

Abstract

While there are many dynamical mechanisms and models that try to explain the origin and phenomenology of the quasi-periodic oscillations (QPOs) seen in the X-ray light curves of low-mass X-ray binaries, few of them address how the radiative processes occurring in these extreme environments give rise to the rich set of variability features actually observed in these light curves. A step towards this end comes from the study of the energy and frequency dependence of the phase lags of these QPOs. Here we used a methodology that allowed us to study, for the first time, the dependence of the phase lags of all QPOs in the range of 1-1300 Hz detected in the low-mass X-ray binary 4U 1636-53 upon energy and frequency as the source changes its states as it moves through the colour-colour diagram. Our results suggest that within the context of models of up-scattering Comptonization, the phase lags dependences upon frequency and energy can be used to extract size scales and physical conditions of the medium that produces the lags. (AU)

• FAPESP's process: 13/26258-4 - Superdense matter in the universe
• Grantee: Manuel Máximo Bastos Malheiro de Oliveira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 11/23996-9 - Compact stars in binaries: investigating the composition of superdense matter
• Grantee: Marcio Guilherme Bronzato de Avellar
• Support Opportunities: Scholarships in Brazil - Post-Doctoral