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The Time-Variable Ultra-Luminous X-ray Sources of "The Antennae"

G. Fabbiano·A. Zezas·A. R. King·T. J. Ponman·A. Rots·Francois Schweizer
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Abstract

We report the first results of the Chandra temporal monitoring of the ultra-luminous X-ray sources (ULXs) in the Antennae galaxies (NGC 4038/39). Observations at four different epochs, covering time scales of 2 years to 2 months, show variability in seven out of nine ULXs, confirming that they are likely to be accreting compact X-ray binaries (XRBs). The seven variable ULXs exhibit a variety of temporal and spectral behaviors: one has harder X-ray colors with decreasing luminosity, similar to the black hole binary Cyg X-1, but four other ULXs show the opposite behavior. We suggest that the latter may be black-hole binaries accreting at very high rates.

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G. Fabbiano, A. Zezas, A. R. King, T. J. Ponman, A. Rots, Francois Schweizer. 2002-12-19. The Time-Variable Ultra-Luminous X-ray Sources of "The Antennae". https://doi.org/10.1086/368174

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