Mon. Not. R. Astron. Soc., 496, 4366-4371 (2020/August-3)
Time lags of the type-B quasi-periodic oscillation in MAXI J1348-630.
BELLONI T.M., ZHANG L., KYLAFIS N.D., REIG P. and ALTAMIRANO D.
Abstract (from CDS):
The fast variability observed in the X-ray emission from black hole binaries has a very complex phenomenology, but offers the possibility to investigate directly the properties of the inner accretion flow. In particular, type-B oscillations in the 2-8 Hz range, observed in the soft-intermediate state, have been associated with the emission from a relativistic jet. We present the results of the timing and spectral analysis of a set of observations of the bright transient MAXI J1348-630 made with the NICER (Neutron Star Interior Composition Explorer) telescope. The observations are in the brightest part of the outburst and all feature a strong type-B quasi-periodic oscillation (QPO) at ∼4.5 Hz. We compute the energy dependence of the fractional rms and the phase lags at the QPO frequency, obtaining high signal-to-noise data and sampling for the first time at energies below 2 keV. The fractional rms decreases from more than 10 per cent at 9 keV to 0.6 per cent at 1.5 keV, and is constant below that energy. Taking the 2-3 keV band as reference, photons at all energies show a hard lag, increasing with the distance from the reference band. The behaviour below 2 keV has never been observed before, due to the higher energy bandpass of previous timing instruments. The energy spectrum can be fitted with a standard model for this state, consisting of a thin disc component and a harder power law, plus an emission line between 6 and 7 keV. We discuss the results, concentrating on the phase lags, and show that they can be interpreted within a Comptonization model.
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
accretion, accretion discs - stars: black holes - stars: jets - X-rays: binaries - X-rays: individual: GRS 1915+105
View the reference in ADS
To bookmark this query, right click on this link: simbad:2020MNRAS.496.4366B and select 'bookmark this link' or equivalent in the popup menu