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http://hdl.handle.net/2445/99489
Title: | The Island State of the Atoll Source 4U 1820-30 |
Author: | Altamirano, Diego Van der Klis, M. Méndez, M. Migliari, Simone Jonker, P. G. Tiengo, A. Zhang, W. |
Keywords: | Estels binaris de raigs X Estels de neutrons Astronomia de raigs X X-ray binaries Neutron stars X-ray astronomy |
Issue Date: | Nov-2005 |
Publisher: | Institute of Physics (IOP) |
Abstract: | We study the rapid X-ray time variability in all public data available from the Rossi X-Ray Timing Explorer Proportional Counter Array on the atoll source 4U 1820-30 in the low-luminosity island state. A total of ~46 ks of data were used. We compare the frequencies of the variability components of 4U 1820-30 with those in other atoll sources. These frequencies were previously found to follow a universal scheme of correlations. We find that 4U 1820-30 shows correlations that are shifted by factors of 1.13 ± 0.01 and 1.21 ± 0.02 with respect to those in other atoll sources. These shifts are similar to, but smaller than, the shift factor of ~1.45 previously reported for some accreting millisecond pulsars. Therefore, 4U 1820-30 is the first atoll source that shows no significant pulsations but has a significant shift in the frequency correlations compared with the other three nonpulsating atoll sources. |
Note: | Reproducció del document publicat a: http://dx.doi.org/10.1086/447761 |
It is part of: | Astrophysical Journal, 2005, vol. 633, num. 1, p. 358-366 |
URI: | http://hdl.handle.net/2445/99489 |
Related resource: | http://dx.doi.org/10.1086/447761 |
ISSN: | 0004-637X |
Appears in Collections: | Articles publicats en revistes (Física Quàntica i Astrofísica) |
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