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dc.date.accessioned 2019-10-18T13:24:56Z
dc.date.available 2019-10-18T13:24:56Z
dc.date.issued 2001-07-26
dc.identifier.uri http://sedici.unlp.edu.ar/handle/10915/83574
dc.description.abstract We study the timing properties of the bursting atoll source 4U 1728-34 as a function of its position in the X-ray color-color diagram. In the island part of the color-color diagram (corresponding to the hardest energy spectra), the power spectrum of 4U 1728-34 shows several features such as a band-limited noise component present up to a few tens of Hz, a low-frequency quasi-periodic oscillation (LFQPO) at frequencies between 20 and 40 Hz, a peaked noise component around 100 Hz, and one or two QPOs at kHz frequencies. In addition to these, in the lower banana (corresponding to softer energy spectra) we also find a very low frequency noise (VLFN) component below ∼1 Hz. In the upper banana (corresponding to the softest energy spectra), the power spectra are dominated by the VLFN, with a peaked noise component around 20 Hz. We find that the frequencies of the kHz QPOs are well correlated with the position in the X-ray color-color diagram. For the frequency of the LFQPO and the break frequency of the broadband noise component, the relation appears more complex. Both of these frequencies increase when the frequency of the upper kHz QPO increases from 400 to 900 Hz, but at this frequency a jump in the values of the parameters occurs. We interpret this jump in terms of the gradual appearance of a QPO at the position of the break at high inferred mass accretion rate, while the previous LFQPO disappears. Simultaneously, another kind of noise appears with a break frequency of ∼7 Hz, similar to the NBO of Z sources. The 100 Hz peaked noise does not seem to correlate with the position of the source in the color-color diagram but remains relatively constant in frequency. This component may be similar to several 100 Hz QPOs observed in black hole binaries. en
dc.format.extent 1107-1120 es
dc.language en es
dc.subject Accretion, accretion disks es
dc.subject Stars: individual (4U 1728-34) es
dc.subject Stars: neutron es
dc.subject X-rays: stars es
dc.title Study of the temporal behavior of 4U 1728-34 as a function of its position in the color-color diagram en
dc.type Articulo es
sedici.identifier.other http://dx.doi.org/10.1086/318278 es
sedici.identifier.issn 0004-637X es
sedici.creator.person Di Salvo, T. es
sedici.creator.person Méndez, Mariano R. es
sedici.creator.person Van Der Klis, M. es
sedici.creator.person Ford, E. es
sedici.creator.person Robba, N. R. es
sedici.subject.materias Ciencias Astronómicas es
sedici.description.fulltext true es
mods.originInfo.place Facultad de Ciencias Astronómicas y Geofísicas es
sedici.subtype Articulo es
sedici.rights.license Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
sedici.rights.uri http://creativecommons.org/licenses/by-nc-sa/4.0/
sedici.description.peerReview peer-review es
sedici.relation.journalTitle Astrophysical Journal es
sedici.relation.journalVolumeAndIssue vol. 546, no. 2 es

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Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) Except where otherwise noted, this item's license is described as Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)