Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T09:36:51.575Z Has data issue: false hasContentIssue false

On the Long-Term Light Curve Behaviour of the Intermediate Polar TX Col

Published online by Cambridge University Press:  12 April 2016

D. A. H. Buckley*
Affiliation:
South African Astronomical Observatory PO Box 9, Observatory 7935, Cape Town, South Africa

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

TX Col (1H0547–407; Porb = 5.72 h) is an intermediate polar (IP) with spin and synodic (beat) periods of 1911s and 2106 s respectively (Buckley & Tuohy 1989). EXOSAT observations (Tuohy et al. 1986) showed the beat period dominated at higher energies (ME; 1… 9keV), while the spin period was stronger in softer X-rays (LE1; 0.1… IkeV). The high flux level, and pulse fraction (>70%), of the soft X-rays were unique in an IP at that time. Now three other IPs, recently discovered from the ROSAT survey, have been found to show a true separate soft X-ray component, similar to the polars (Motch & Haberl 1994).

The strength of the synodic X-ray period in TX Col was, until the recent discovery of the variable polarised IP, RX J1712.6–2414 (Buckley et al. 1995), unique. This was taken as evidence for direct accretion onto the magnetosphere (e.g. Mason, Rosen & Hellier 1988), through a component of the accretion stream overflowing the disc (Hellier 1992).

Type
Intermediate Polars
Copyright
Copyright © Kluwer 1996

References

Buckley, D.A.H., Tuohy, I.R., 1989, Ap. J., 344, 376 CrossRefGoogle Scholar
Buckley, D.A.H., Sullivan, D.J., 1992, in “Proceedings if the Viña del Mar Workshop on Cataclysmic Variables”, ASP Conference Series (Vogt, N., ed.), 29, 387 Google Scholar
Buckley, D.A.H., et al., 1995, MNRAS, in pressGoogle Scholar
Heilier, C., 1992, MNRAS, 258, 578 CrossRefGoogle Scholar
Mason, K.O., Rosen, S.R., Hellier, C., 1988, in “The Physics of Compact Objects”, eds. White, N.S, Filipov, L.G., Pergamon Press, Adv. Space Res. 8 (2), 293 Google Scholar
Motch, C., Haberl, F., 1995, in “Magnetic Cataclysmic Variables”, eds Buckley, D., Warner, B., ASP Conf. Ser. 85, 109 Google Scholar
Tuohy, I.R., et al., 1986, Ap. J., 311, 275 CrossRefGoogle Scholar