@article{6cf42228341f442aa52c9213bcbaa22e,
title = "Fast infrared variability from a relativistic jet in GX 339-4",
abstract = "We present the discovery of fast infrared/X-ray correlated variability in the black hole transient GX 339-4. The source was observed with subsecond time resolution simultaneously with Very Large Telescope/Infrared Spectrometer And Array Camera and Rossi X-ray Timing Explorer/Proportional Counter Array in 2008 August, during its persistent low-flux highly variable hard state. The data show a strong correlated variability, with the infrared emission lagging the X-ray emission by 100 ms. The short time delay and the nearly symmetric cross-correlation function, together with the measured brightness temperature of \textasciitilde{}2.5 × 106 K, indicate that the bright and highly variable infrared emission most likely comes from a jet near the black hole. Under standard assumptions about jet physics, the measured time delay can provide us a lower limit of Γ > 2 for the Lorentz factor of the jet. This suggests that jets from stellar-mass black holes are at least mildly relativistic near their launching region. We discuss implications for future applications of this technique.",
keywords = "Black hole physics, Stars: winds, outflows, X-rays: binaries, X-rays: individual: GX 339-4",
author = "P. Casella and Maccarone, \{T. J.\} and K. O'Brien and Fender, \{R. P.\} and Russell, \{D. M.\} and \{van der Klis\}, M. and A. Pe'er and D. Maitra and D. Altamirano and T. Belloni and G. Kanbach and M. Klein-Wolt and E. Mason and P. Soleri and A. Stefanescu and K. Wiersema and R. Wijnands",
year = "2010",
month = may,
doi = "10.1111/j.1745-3933.2010.00826.x",
language = "אנגלית",
volume = "404",
pages = "L21--L25",
journal = "Monthly Notices of the Royal Astronomical Society: Letters",
issn = "1745-3933",
publisher = "Oxford University Press",
number = "1",
}