Chandra Monitoring Observations of the Antennae Galaxies. I. Catalog of Source properties

A Zezas, G Fabbiano, A Baldi, F Schweizer, AR King, Trevor Ponman, AH Rots

Research output: Contribution to journalArticle

38 Citations (Scopus)


We present the properties of the discrete X-ray sources detected in our monitoring survey of the Antennae galaxies with Chandra ACIS-S. We detect similar to 70 sources down to a typical luminosity of 7 x 10(37) ergs s(-1) in each of the six monitoring observations. In the co-added observation (which has a total exposure of 411 ks) we detect a total of 120 sources down to a luminosity of (2-5) x 10(37) ergs s(-1), depending on the local background. Fifteen sources have a strong extended component. Fourteen of the pointlike sources have luminosities above 10(39) ergs s(-1), at least in one exposure, which qualifies them as ultraluminous X-ray sources (ULXs). Ten of the ULXs show long- term variability, while one is observed only once, suggesting that it is a transient source. We find that 25 sources exhibit long-term variability clearly associating them with accreting compact objects. Twenty-one sources also show spectral variability. However, their variability patterns are diverse, indicating that they belong to different source classes. Finally, we find a weak excess of hard sources at the low luminosities that we tentatively associate with pulsar X-ray binaries.
Original languageEnglish
Pages (from-to)211-248
Number of pages38
JournalAstrophysical Journal. Supplement Series
Issue number1
Publication statusPublished - 1 Sept 2006


  • galaxies : peculiar
  • X-rays : galaxies
  • galaxies : interactions
  • X-rays : binaries
  • galaxies : individual ( NGC 4038/39)


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