Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44
- Autores
- Wijnands, Rudy; van der Klis, Michiel; Méndez, Mariano R.; van Paradijs, Jan; Lewin, Walter H. G.; Lamb, Frederick K.; Vaughan, Brian A.; Kuulkers, Erik
- Año de publicación
- 1998
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- We discovered a single kilohertz (kHz) quasi-periodic oscillation (QPO) near 1150 Hz in the Rossi X-Ray Timing Explorer X-ray light curve of the low-mass X-ray binary and atoll source 4U 1735-44. The rms amplitude of this peak was 2%-3%, and the FWHM was 6-40 Hz. There are indications that the kHz QPO frequency decreased from 1160 to 1145 Hz when the count rate increased, which would be quite different from what is observed in other atoll sources for which kHz QPOs have been discovered. In the X-ray color-color diagram and hardness-intensity diagram, the source traced out the curved branch (the so-called banana branch) that has been found by previous instruments. The kHz QPO was detected only when the source was at the lowest count rates during our observations, i.e., on the lower part of the banana branch. When 4U 1735-44 was at higher count rates, i.e., on the upper part of the banana branch and at a higher inferred mass accretion rate with respect to that on the lower part of the banana branch, the QPO was not detected. Besides the kHz QPO, we discovered a low-frequency QPO with a frequency near 67 Hz, together with a complex, broad-peaked noise component below 30 Hz. This 67 Hz QPO may be related to the magnetospheric beat-frequency QPO, which is observed on the horizontal branch of Z sources. This idea is supported by the (peaked) noise found in both 4U 1735-44 and Z sources at frequencies just below the QPO frequency.
Facultad de Ciencias Astronómicas y Geofísicas - Materia
-
Ciencias Astronómicas
Accretion disks
Stars: individual (4U 1735244)
Stars: neutron
X-rays: stars - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/122871
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Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44Wijnands, Rudyvan der Klis, MichielMéndez, Mariano R.van Paradijs, JanLewin, Walter H. G.Lamb, Frederick K.Vaughan, Brian A.Kuulkers, ErikCiencias AstronómicasAccretion disksStars: individual (4U 1735244)Stars: neutronX-rays: starsWe discovered a single kilohertz (kHz) quasi-periodic oscillation (QPO) near 1150 Hz in the Rossi X-Ray Timing Explorer X-ray light curve of the low-mass X-ray binary and atoll source 4U 1735-44. The rms amplitude of this peak was 2%-3%, and the FWHM was 6-40 Hz. There are indications that the kHz QPO frequency decreased from 1160 to 1145 Hz when the count rate increased, which would be quite different from what is observed in other atoll sources for which kHz QPOs have been discovered. In the X-ray color-color diagram and hardness-intensity diagram, the source traced out the curved branch (the so-called banana branch) that has been found by previous instruments. The kHz QPO was detected only when the source was at the lowest count rates during our observations, i.e., on the lower part of the banana branch. When 4U 1735-44 was at higher count rates, i.e., on the upper part of the banana branch and at a higher inferred mass accretion rate with respect to that on the lower part of the banana branch, the QPO was not detected. Besides the kHz QPO, we discovered a low-frequency QPO with a frequency near 67 Hz, together with a complex, broad-peaked noise component below 30 Hz. This 67 Hz QPO may be related to the magnetospheric beat-frequency QPO, which is observed on the horizontal branch of Z sources. This idea is supported by the (peaked) noise found in both 4U 1735-44 and Z sources at frequencies just below the QPO frequency.Facultad de Ciencias Astronómicas y Geofísicas1998info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfL39-L42http://sedici.unlp.edu.ar/handle/10915/122871enginfo:eu-repo/semantics/altIdentifier/issn/0004-637Xinfo:eu-repo/semantics/altIdentifier/arxiv/astro-ph/9801018info:eu-repo/semantics/altIdentifier/doi/10.1086/311217info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:29:14Zoai:sedici.unlp.edu.ar:10915/122871Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:29:15.047SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
title |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
spellingShingle |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 Wijnands, Rudy Ciencias Astronómicas Accretion disks Stars: individual (4U 1735244) Stars: neutron X-rays: stars |
title_short |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
title_full |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
title_fullStr |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
title_full_unstemmed |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
title_sort |
Discovery of Kilohertz Quasi-periodic Oscillations in 4U 1735-44 |
dc.creator.none.fl_str_mv |
Wijnands, Rudy van der Klis, Michiel Méndez, Mariano R. van Paradijs, Jan Lewin, Walter H. G. Lamb, Frederick K. Vaughan, Brian A. Kuulkers, Erik |
author |
Wijnands, Rudy |
author_facet |
Wijnands, Rudy van der Klis, Michiel Méndez, Mariano R. van Paradijs, Jan Lewin, Walter H. G. Lamb, Frederick K. Vaughan, Brian A. Kuulkers, Erik |
author_role |
author |
author2 |
van der Klis, Michiel Méndez, Mariano R. van Paradijs, Jan Lewin, Walter H. G. Lamb, Frederick K. Vaughan, Brian A. Kuulkers, Erik |
author2_role |
author author author author author author author |
dc.subject.none.fl_str_mv |
Ciencias Astronómicas Accretion disks Stars: individual (4U 1735244) Stars: neutron X-rays: stars |
topic |
Ciencias Astronómicas Accretion disks Stars: individual (4U 1735244) Stars: neutron X-rays: stars |
dc.description.none.fl_txt_mv |
We discovered a single kilohertz (kHz) quasi-periodic oscillation (QPO) near 1150 Hz in the Rossi X-Ray Timing Explorer X-ray light curve of the low-mass X-ray binary and atoll source 4U 1735-44. The rms amplitude of this peak was 2%-3%, and the FWHM was 6-40 Hz. There are indications that the kHz QPO frequency decreased from 1160 to 1145 Hz when the count rate increased, which would be quite different from what is observed in other atoll sources for which kHz QPOs have been discovered. In the X-ray color-color diagram and hardness-intensity diagram, the source traced out the curved branch (the so-called banana branch) that has been found by previous instruments. The kHz QPO was detected only when the source was at the lowest count rates during our observations, i.e., on the lower part of the banana branch. When 4U 1735-44 was at higher count rates, i.e., on the upper part of the banana branch and at a higher inferred mass accretion rate with respect to that on the lower part of the banana branch, the QPO was not detected. Besides the kHz QPO, we discovered a low-frequency QPO with a frequency near 67 Hz, together with a complex, broad-peaked noise component below 30 Hz. This 67 Hz QPO may be related to the magnetospheric beat-frequency QPO, which is observed on the horizontal branch of Z sources. This idea is supported by the (peaked) noise found in both 4U 1735-44 and Z sources at frequencies just below the QPO frequency. Facultad de Ciencias Astronómicas y Geofísicas |
description |
We discovered a single kilohertz (kHz) quasi-periodic oscillation (QPO) near 1150 Hz in the Rossi X-Ray Timing Explorer X-ray light curve of the low-mass X-ray binary and atoll source 4U 1735-44. The rms amplitude of this peak was 2%-3%, and the FWHM was 6-40 Hz. There are indications that the kHz QPO frequency decreased from 1160 to 1145 Hz when the count rate increased, which would be quite different from what is observed in other atoll sources for which kHz QPOs have been discovered. In the X-ray color-color diagram and hardness-intensity diagram, the source traced out the curved branch (the so-called banana branch) that has been found by previous instruments. The kHz QPO was detected only when the source was at the lowest count rates during our observations, i.e., on the lower part of the banana branch. When 4U 1735-44 was at higher count rates, i.e., on the upper part of the banana branch and at a higher inferred mass accretion rate with respect to that on the lower part of the banana branch, the QPO was not detected. Besides the kHz QPO, we discovered a low-frequency QPO with a frequency near 67 Hz, together with a complex, broad-peaked noise component below 30 Hz. This 67 Hz QPO may be related to the magnetospheric beat-frequency QPO, which is observed on the horizontal branch of Z sources. This idea is supported by the (peaked) noise found in both 4U 1735-44 and Z sources at frequencies just below the QPO frequency. |
publishDate |
1998 |
dc.date.none.fl_str_mv |
1998 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Articulo http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
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article |
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publishedVersion |
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http://sedici.unlp.edu.ar/handle/10915/122871 |
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http://sedici.unlp.edu.ar/handle/10915/122871 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
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info:eu-repo/semantics/altIdentifier/issn/0004-637X info:eu-repo/semantics/altIdentifier/arxiv/astro-ph/9801018 info:eu-repo/semantics/altIdentifier/doi/10.1086/311217 |
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info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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