The Island State of the Atoll Source 4U 1820-30
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 4...
| Autores: | , , , , , , |
|---|---|
| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | España |
| Recursos: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/99489 |
| Acesso em linha: | https://hdl.handle.net/2445/99489 |
| Access Level: | acceso abierto |
| Palavra-chave: | Estels binaris de raigs X Estels de neutrons Astronomia de raigs X X-ray binaries Neutron stars X-ray astronomy |
| Resumo: | 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. |
|---|