A new candidate Wolf-Rayet X-ray binary in NGC 253

Thomas J. Maccarone, Bret D. Lehmer, J. C. Leyder, Vallia Antoniou, Ann Hornschemeier, Andrew Ptak, Daniel Wik, Andreas Zezas

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


We have discovered a persistent, but highly variableX-ray source in the nearby starburst galaxy NGC 253. The source varies at the level of a factor of about 5 in count rate on time-scales of a few hours. Two long observations of the source with Chandra and XMM-Newton show suggestive evidence for the source having a period of about 14-15 hours, but the time sampling in existing data is insufficient to allow a firm determination that the source is periodic. Given the amplitude of variation and the location in a nuclear starburst, the source is likely to be a Wolf-Rayet X-ray binary, with the tentative period being the orbital period of the system. In light of the fact that we have demonstrated that careful examination of the variability of moderately bright X-ray sources in nearby galaxies can turn up candidate Wolf-Rayet X-ray binaries, we discuss the implications of Wolf-Rayet X-ray binaries for predictions of the gravitational wave source event rate, and, potentially, interpretations of the events.

Original languageEnglish
Pages (from-to)3064-3072
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
StatePublished - Apr 2014


  • Galaxies: individual: NGC 253-Galaxies: starburst
  • Rayet
  • Stars:Wolf
  • X-rays: binaries


Dive into the research topics of 'A new candidate Wolf-Rayet X-ray binary in NGC 253'. Together they form a unique fingerprint.

Cite this