Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52
We present new Rossi X-ray Timing Explorer observations of the low-mass X-ray binary 4U 1608-52 during the decay of its 1998 outburst. We detect by a direct FFT method the existence of a second kilohertz quasi-periodic oscillation (kHz QPO) in its power density spectrum, previously only seen by mean...
| Autores principales: | , , , , , |
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| Formato: | Articulo Preprint |
| Lenguaje: | Inglés |
| Publicado: |
1998
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/123191 |
| Aporte de: |
| id |
I19-R120-10915-123191 |
|---|---|
| record_format |
dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Astronómicas Accretion, accretion disks Stars: neutron Stars: individual (4 U 1608–52) X-rays: stars |
| spellingShingle |
Ciencias Astronómicas Accretion, accretion disks Stars: neutron Stars: individual (4 U 1608–52) X-rays: stars Méndez, Mariano R. van der Klis, Michiel Wijnands, Rudy Ford, Eric van Paradijs, Jan Vaughan, Brian A. Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52 |
| topic_facet |
Ciencias Astronómicas Accretion, accretion disks Stars: neutron Stars: individual (4 U 1608–52) X-rays: stars |
| description |
We present new Rossi X-ray Timing Explorer observations of the low-mass X-ray binary 4U 1608-52 during the decay of its 1998 outburst. We detect by a direct FFT method the existence of a second kilohertz quasi-periodic oscillation (kHz QPO) in its power density spectrum, previously only seen by means of the sensitivity-enhancing `shift and add' technique. This result confirms that 4U 1608-52 is a twin kHz QPO source. The frequency separation between these two QPO decreased significantly, from 325.5 +/- 3.4 Hz to 225.3 +/- 12.0 Hz, as the frequency of the lower kHz QPO increased from 470 Hz to 865 Hz, in contradiction with a simple beat-frequency interpretation. This change in the peak separation of the kHz QPOs is closely similar to that previously seen in Sco X-1, but takes place at a ten times lower average luminosity. We discuss this result within the framework of models that have been proposed for kHz QPO. Beat frequency models where the peak separation is identified with the neutron star spin rate, as well as the explanations previously proposed to account for the similar behavior of the QPOs in Sco X-1, are strongly challenged by this result. |
| format |
Articulo Preprint |
| author |
Méndez, Mariano R. van der Klis, Michiel Wijnands, Rudy Ford, Eric van Paradijs, Jan Vaughan, Brian A. |
| author_facet |
Méndez, Mariano R. van der Klis, Michiel Wijnands, Rudy Ford, Eric van Paradijs, Jan Vaughan, Brian A. |
| author_sort |
Méndez, Mariano R. |
| title |
Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52 |
| title_short |
Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52 |
| title_full |
Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52 |
| title_fullStr |
Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52 |
| title_full_unstemmed |
Kilohertz Quasi-Periodic Oscillation Peak Separation is not Constant in the Atoll Source 4U 1608-52 |
| title_sort |
kilohertz quasi-periodic oscillation peak separation is not constant in the atoll source 4u 1608-52 |
| publishDate |
1998 |
| url |
http://sedici.unlp.edu.ar/handle/10915/123191 |
| work_keys_str_mv |
AT mendezmarianor kilohertzquasiperiodicoscillationpeakseparationisnotconstantintheatollsource4u160852 AT vanderklismichiel kilohertzquasiperiodicoscillationpeakseparationisnotconstantintheatollsource4u160852 AT wijnandsrudy kilohertzquasiperiodicoscillationpeakseparationisnotconstantintheatollsource4u160852 AT forderic kilohertzquasiperiodicoscillationpeakseparationisnotconstantintheatollsource4u160852 AT vanparadijsjan kilohertzquasiperiodicoscillationpeakseparationisnotconstantintheatollsource4u160852 AT vaughanbriana kilohertzquasiperiodicoscillationpeakseparationisnotconstantintheatollsource4u160852 |
| bdutipo_str |
Repositorios |
| _version_ |
1764820449931296768 |