English

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

Astrophysics 2016-08-30 v1

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.

Keywords

Cite

@article{arxiv.astro-ph/0212437,
  title  = {The Time-Variable Ultra-Luminous X-ray Sources of "The Antennae"},
  author = {G. Fabbiano and A. Zezas and A. R. King and T. J. Ponman and A. Rots and Francois Schweizer},
  journal= {arXiv preprint arXiv:astro-ph/0212437},
  year   = {2016}
}

Comments

3 pages, 3 figures, 1 table In press in Ap. J. Letters