XMM-Newton observations of AM CVn binaries
In: Astronomy and astrophysics (Berlin. Print), Jg. 440 (2005), Heft 2, S. 675-681
Online
academicJournal
- print, 32 ref
Zugriff:
We present the results of XMM-Newton observations of four AM CVn systems - AM CVn, CR Boo, HP Lib and GP Com. Their light curves show very different characteristics. The X-ray light curves show no coherent pulsations, suggesting the accreting white dwarfs have relatively low magnetic field strengths. Their spectra were best modelled using a multi-temperature emission model and a strong UV component. We find that CR Boo and HP Lib have X-ray spectra with abundances consistent with relatively low temperature CNO processed material, while AM CVn and GP Com show an enhancement of nitrogen. A.large fraction of the accretion luminosity is emitted in the UV. We determine accretion luminosities of ∼1.6 × 1033 erg s-1 and 1.7 × 1031 erg s-1 for AM CVn and GP Corn respectively. Comparing the implied mass transfer rates with that derived using model fits to optical and UV spectra, we find evidence that in the case of AM CVn, we do not detect a significant proportion of the accretion energy. This missing component could be lost in the form of a wind.
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XMM-Newton observations of AM CVn binaries
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Autor/in / Beteiligte Person: | RAMSAY, G ; HAKALA, P ; MARSH, T ; NELEMANS, G ; STEEGHS, D ; CROPPER, M |
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Zeitschrift: | Astronomy and astrophysics (Berlin. Print), Jg. 440 (2005), Heft 2, S. 675-681 |
Veröffentlichung: | Les Ulis: EDP Sciences, 2005 |
Medientyp: | academicJournal |
Umfang: | print, 32 ref |
ISSN: | 0004-6361 (print) |
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