Query : 2015MNRAS.449.4027A

2015MNRAS.449.4027A - Mon. Not. R. Astron. Soc., 449, 4027-4037 (2015/June-1)

The evolution of the X-ray phase lags during the outbursts of the black hole candidate GX 339-4.


Abstract (from CDS):

Owing to the frequency and reproducibility of its outbursts, the black hole candidate GX 339-4 has become the standard against which the outbursts of other black hole candidate are matched up. Here we present the first systematic study of the evolution of the X-ray lags of the broad-band variability component (0.008-5 Hz) in GX 339-4 as a function of the position of the source in the hardness-intensity diagram. The hard photons always lag the soft ones, consistent with previous results. In the low-hard state the lags correlate with X-ray intensity, and as the source starts the transition to the intermediate/soft states, the lags first increase faster, and then appear to reach a maximum, although the exact evolution depends on the outburst and the energy band used to calculate the lags. The time of the maximum of the lags appears to coincide with a sudden drop of the optical/near-infrared flux, the fractional rms amplitude of the broad-band component in the power spectrum, and the appearance of a thermal component in the X-ray spectra, strongly suggesting that the lags can be very useful to understand the physical changes that GX 339-4 undergoes during an outburst. We find strong evidence for a connection between the evolution of the cut-off energy of the hard component in the energy spectrum and the phase lags, suggesting that the average magnitude of the lags is correlated with the properties of the corona/jet rather than those of the disc. Finally, we show that the lags in GX 339-4 evolve in a similar manner to those of the black hole candidate Cygnus X-1, suggesting similar phenomena could be observable in other black hole systems.

Abstract Copyright: © 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2015)

Journal keyword(s): accretion, accretion discs - black hole physics - X-rays: binaries

Simbad objects: 6

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Number of rows : 6
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
1 M 1 SNR 05 34 31.94 +22 00 52.2           ~ 5764 4
2 NGC 4051 Sy1 12 03 09.6098828919 +44 31 52.693714606   11.08 12.92 9.94   ~ 2042 1
3 V* V381 Nor HXB 15 50 58.6520652623 -56 28 35.309070422   17.95 16.6     K3III 1072 0
4 V* V821 Ara HXB 17 02 49.3810714542 -48 47 23.163091737 16.20 16.30 15.5     ~ 1844 0
5 V* V406 Vul HXB 18 58 41.580 +22 39 29.40 15.00 15.65 15.31     G5V-K0V 329 0
6 HD 226868 HXB 19 58 21.6758193269 +35 12 05.782512305 9.38 9.72 8.91 8.42   O9.7Iabpvar 4022 0

    Equat.    Gal    SGal    Ecl

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