Comparison of time/phase lags in the hard state and plateau state of GRS 1915+105

Abstract

We investigate the complex behavior of energy- and frequency-dependent time/phase lags in the plateau state and the radio-quiet hard state of GRS 1915+105. In our timing analysis, we find that when the source is faint in the radio, QPOs are observed above 2 Hz and typically exhibit soft lags (soft photons lag hard photons), whereas QPOs in the radio-bright plateau state are found below 2.2 Hz and consistently show hard lags. The phase lag at the QPO frequency is strongly anti-correlated with the QPO frequency, changing sign at 2.2 Hz. However, the phase lag at the frequency of the first harmonic is positive and nearly independent of frequency at at ~0.172 rad, regardless of the radio emission. The lag-energy dependence at the first harmonic is also independent of radio flux. However, the lags at the QPO frequency are negative at all energies during the radio-quiet state, but lags at the QPO frequency during the plateau state are positive at all energies and show a 'reflection-type' evolution of the lag-energy spectra with respect to the radio-quiet state. The lag-energy dependence is roughly logarithmic, but there is some evidence for a break around 4-6 keV. Finally, the Fourier frequency-dependent phase lag spectra are fairly flat during the plateau state, but increase from negative to positive during the radio-quiet state. We discuss the implications of our results in the light of some generic models.

9 pages, 7 figures, accepted for publication in ApJ

References in corpus (2)

• A Statistical Study on the Low-Frequency QPO Amplitude Spectrum and Amplitude in GRS 1915+105
• Connection between accretion disk and superluminal radio jets and the role of radio plateau state in GRS 1915+105

Cited by in corpus (24)

• Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT
• No Time for Dead Time: Timing analysis of bright black hole binaries with NuSTAR
• Inclination dependence of QPO phase lags in black hole X-ray binaries
• AstroSat/LAXPC reveals the high energy variability of GRS 1915+105 in the chi class
• A Systematic Analysis of the Phase Lags Associated with the Type-C Quasi-periodic Oscillation in GRS 1915+105
• A variable corona for GRS 1915+105
• Probing the origin of quasi-periodic oscillations: the short-timescale evolution of phase lags in GRS 1915+105
• The evolving properties of the corona of GRS 1915+105: A spectral-timing perspective through variable-Comptonisation modelling
• The Evolution of the Phase Lags Associated with the Type-C Quasi-periodic Oscillation in GX 339--4 during the 2006/2007 Outburst
• Variability and phase lags of the type-C quasi-periodic oscillation of MAXI J1348-630 with NICER
• An Atlas of Exotic Variability in IGR J17091-3624: A Comparison with GRS 1915+105
• ALMA/NICER observations of GRS 1915+105 indicate a return to a hard state
• Study of timing evolution from non-variable to structured large-amplitude variability transition in GRS 1915+105 using AstroSat
• A Phase Lag between Disk and Corona in GRMHD Simulations of Precessing Tilted Accretion Disks
• Identifying the radiative components responsible for Quasi-Periodic Oscillations of black hole systems
• A model for the energy-dependent time-lag and rms of the heartbeat oscillations in GRS 1915+105
• The evolution of the high-frequency variability in the black hole candidate GRS 1915+105 as seen by RXTE
• Using the bispectrum to probe radio X-ray correlations in GRS 1915+105
• Detection of distinct power spectra in soft and hard X-ray bands in the hard state of GRS 1915+105
• A timing view of the heartbeat state of GRS 1915+105
• The NuSTAR View of a QPO Evolution of GRS 1915+105
• The cross-correlation analysis in Z source GX 349+2
• Probing black-hole accretion through time variability
• Recurrent Instability in LMXB Accretion Disks: How Strange is GRS 1915+105?