Astron. Astrophys. 336, 895-901 (1998)

Nine X-ray sources in the globular cluster 47 Tucanae

F. Verbunt ¹ and G. Hasinger <sup>2

1</sup> Astronomical Institute, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
² Astrophysikalisches Institut, An der Sternwarte 16, D-14482 Potsdam, Germany

Received 25 March 1998 / Accepted 25 May 1998

Abstract

We analyze ROSAT HRI observations obtained from 1992 to 1996 of the globular cluster 47 Tuc. Identifications of two X-ray sources with HD 2072 and with a galaxy, respectively, are used to obtain accurate () positions of the X-ray sources in the cluster. We find possible optical counterparts, including the blue objects V 1 and V 2, for three X-ray sources in the core of 47 Tuc, but note that the probability of chance positional coincidence is significant.

One of the five sources previously reported by us to reside in the cluster core is found to be an artefact of misalignment between subsequent satellite pointings.

Key words: globular clusters: individual: 47 Tuc X-rays: stars

Send offprint requests to: F. Verbunt

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and data analysis
  • 2.1. Co-alignment of the separate observations
  • 2.2. Conversion to the optical coordinate frame
  • 2.3. Multiple source detection and variability
• 3. Results
  • 3.1. Inside the core
  • 3.2. Near the core; extended emission
  • 3.3. Sources not related to 47 Tuc
• 4. Discussion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: July 27, 1998
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