EDP Sciences
Free access
Issue
A&A
Volume 406, Number 1, July IV 2003
Page(s) 233 - 243
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20030681


A&A 406, 233-243 (2003)
DOI: 10.1051/0004-6361:20030681

Bursts, eclipses, dips and a refined position for the luminous low-mass X-ray binary in the globular cluster Terzan 6

J. J. M. in 't Zand1, 2, F. Hulleman2, C. B. Markwardt3, 4, M. Méndez1, E. Kuulkers5, R. Cornelisse1, 2, J. Heise1, 2, T. E. Strohmayer3 and F. Verbunt2

1  SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
2  Astronomical Institute, Utrecht University, PO Box 80000, 3508 TA Utrecht, The Netherlands
3  NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771, USA
4  Dept. of Astronomy, University of Maryland, College Park, MD 20742, USA
5  ESA-ESTEC, Science Operations & Data Systems Division, SCI-SDG, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands

(Received 21 February 2003 / Accepted 6 May 2003 )

Abstract
GRS 1747-312 is a bright transient X-ray source in the globular cluster Terzan 6 with quasi-periodic outbursts approximately every 4.5 months. We carried out 2-60 keV target-of-opportunity observations during eight outbursts with the Proportional Counter Array on the RXTE satellite, for a total exposure time of 301 ks, and detect the first unambiguous thermonuclear X-ray bursts from this source. This identifies the compact accretor in this binary as a neutron star. The neutron star identification implies that twelve out of thirteen luminous (above 10 36 erg s -1) X-ray sources in Galactic globular clusters harbor neutron stars, with AC211's nature (in M15) remaining elusive. We observed 24 transitions of eclipses of the X-ray emitting region by the companion star and are able to improve the accuracy of the orbital period by a factor of 10 4. The period is P=0.514980303(7) d. We do not detect a period derivative with an upper limit of $\vert\dot{P}/P\vert=3\times10^{-8}$ yr -1. Archival Chandra data were analyzed to further refine the X-ray position, and the cluster's center of gravity was re-determined from optical data resulting in a correction amounting to 2 core radii. We find that GRS 1747-312 is $0.2\pm0.2$ core radii from the cluster center.


Key words: accretion, accretion disks -- globular clusters: individual: Terzan 6 -- X-rays: binaries -- X-rays: bursts -- X-rays: individual: GRS 1747-312

Offprint request: J. J. M. in 't Zand, jeanz@sron.nl



© ESO 2003

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.