Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37

Autores
Jonker, Peter G.; Klis, Michiel van der; Homan, Jeroen; Wijnands, Rudy; Paradijs, Jan van; Méndez, Mariano R.; Kuulkers, Erik; Ford, Eric
Año de publicación
2000
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We have discovered a ~1 Hz quasi-periodic oscillation (QPO) present in the persistent X-ray emission of the globular cluster source, dipper, and low-mass X-ray binary (LMXB) 4U 1746-37. The QPO was also observed during type I X-ray bursts. The QPO properties resemble those of QPOs found recently in the LMXB dippers 4U 1323-62 and EXO 0748-676, which makes 4U 1746-37 the third source known to exhibit this type of QPO. We present evidence for X-ray spectral changes in this source similar to those observed in LMXBs referred to as atoll sources. We detect two states, a lower intensity and spectrally hard state and a higher intensity and spectrally soft state. This may explain the different spectral characteristics reported for 4U 1746-37 earlier. The high-intensity state resembles the banana branch state of atoll sources. The QPOs are seen only in the low-intensity state and are absent when the source is in the banana branch. This strongly suggests that either the accretion disk or an extended central source changes shape between the low-intensity state and the banana branch. Twelve bursts were detected, of which five took place while the source was on the banana branch and seven while the source was in the low-intensity state. The bursts occurring on the banana branch had an e-folding time ~3 times longer than those that occurred in the low-intensity state. Whereas previously detected dips showed a decrease in count rate of only ~15%, we found a dip in one observation for which the count rate dropped from ~200 counts s⁻¹ to ~20 counts s⁻¹. This dip lasted only ~250 s, during which clear spectral hardening occurred. This is the first time strong evidence for spectral changes during a dip have been reported for this source.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Astronomía
accretion, accretion disks
stars: individual (4U 1746-37)
stars: neutron
X-rays: stars
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/125013

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repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37Jonker, Peter G.Klis, Michiel van derHoman, JeroenWijnands, RudyParadijs, Jan vanMéndez, Mariano R.Kuulkers, ErikFord, EricAstronomíaaccretion, accretion disksstars: individual (4U 1746-37)stars: neutronX-rays: starsWe have discovered a ~1 Hz quasi-periodic oscillation (QPO) present in the persistent X-ray emission of the globular cluster source, dipper, and low-mass X-ray binary (LMXB) 4U 1746-37. The QPO was also observed during type I X-ray bursts. The QPO properties resemble those of QPOs found recently in the LMXB dippers 4U 1323-62 and EXO 0748-676, which makes 4U 1746-37 the third source known to exhibit this type of QPO. We present evidence for X-ray spectral changes in this source similar to those observed in LMXBs referred to as atoll sources. We detect two states, a lower intensity and spectrally hard state and a higher intensity and spectrally soft state. This may explain the different spectral characteristics reported for 4U 1746-37 earlier. The high-intensity state resembles the banana branch state of atoll sources. The QPOs are seen only in the low-intensity state and are absent when the source is in the banana branch. This strongly suggests that either the accretion disk or an extended central source changes shape between the low-intensity state and the banana branch. Twelve bursts were detected, of which five took place while the source was on the banana branch and seven while the source was in the low-intensity state. The bursts occurring on the banana branch had an e-folding time ~3 times longer than those that occurred in the low-intensity state. Whereas previously detected dips showed a decrease in count rate of only ~15%, we found a dip in one observation for which the count rate dropped from ~200 counts s⁻¹ to ~20 counts s⁻¹. This dip lasted only ~250 s, during which clear spectral hardening occurred. This is the first time strong evidence for spectral changes during a dip have been reported for this source.Facultad de Ciencias Astronómicas y Geofísicas2000-03-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf453-457http://sedici.unlp.edu.ar/handle/10915/125013enginfo:eu-repo/semantics/altIdentifier/issn/0004-637Xinfo:eu-repo/semantics/altIdentifier/issn/1538-4357info:eu-repo/semantics/altIdentifier/doi/10.1086/308471info: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:UNLP2025-10-22T17:10:39Zoai:sedici.unlp.edu.ar:10915/125013Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-22 17:10:40.163SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
title Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
spellingShingle Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
Jonker, Peter G.
Astronomía
accretion, accretion disks
stars: individual (4U 1746-37)
stars: neutron
X-rays: stars
title_short Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
title_full Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
title_fullStr Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
title_full_unstemmed Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
title_sort Discovery of a ~1 Hz Quasi-periodic Oscillation in the Low-Mass X-Ray Binary 4U 1746–37
dc.creator.none.fl_str_mv Jonker, Peter G.
Klis, Michiel van der
Homan, Jeroen
Wijnands, Rudy
Paradijs, Jan van
Méndez, Mariano R.
Kuulkers, Erik
Ford, Eric
author Jonker, Peter G.
author_facet Jonker, Peter G.
Klis, Michiel van der
Homan, Jeroen
Wijnands, Rudy
Paradijs, Jan van
Méndez, Mariano R.
Kuulkers, Erik
Ford, Eric
author_role author
author2 Klis, Michiel van der
Homan, Jeroen
Wijnands, Rudy
Paradijs, Jan van
Méndez, Mariano R.
Kuulkers, Erik
Ford, Eric
author2_role author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Astronomía
accretion, accretion disks
stars: individual (4U 1746-37)
stars: neutron
X-rays: stars
topic Astronomía
accretion, accretion disks
stars: individual (4U 1746-37)
stars: neutron
X-rays: stars
dc.description.none.fl_txt_mv We have discovered a ~1 Hz quasi-periodic oscillation (QPO) present in the persistent X-ray emission of the globular cluster source, dipper, and low-mass X-ray binary (LMXB) 4U 1746-37. The QPO was also observed during type I X-ray bursts. The QPO properties resemble those of QPOs found recently in the LMXB dippers 4U 1323-62 and EXO 0748-676, which makes 4U 1746-37 the third source known to exhibit this type of QPO. We present evidence for X-ray spectral changes in this source similar to those observed in LMXBs referred to as atoll sources. We detect two states, a lower intensity and spectrally hard state and a higher intensity and spectrally soft state. This may explain the different spectral characteristics reported for 4U 1746-37 earlier. The high-intensity state resembles the banana branch state of atoll sources. The QPOs are seen only in the low-intensity state and are absent when the source is in the banana branch. This strongly suggests that either the accretion disk or an extended central source changes shape between the low-intensity state and the banana branch. Twelve bursts were detected, of which five took place while the source was on the banana branch and seven while the source was in the low-intensity state. The bursts occurring on the banana branch had an e-folding time ~3 times longer than those that occurred in the low-intensity state. Whereas previously detected dips showed a decrease in count rate of only ~15%, we found a dip in one observation for which the count rate dropped from ~200 counts s⁻¹ to ~20 counts s⁻¹. This dip lasted only ~250 s, during which clear spectral hardening occurred. This is the first time strong evidence for spectral changes during a dip have been reported for this source.
Facultad de Ciencias Astronómicas y Geofísicas
description We have discovered a ~1 Hz quasi-periodic oscillation (QPO) present in the persistent X-ray emission of the globular cluster source, dipper, and low-mass X-ray binary (LMXB) 4U 1746-37. The QPO was also observed during type I X-ray bursts. The QPO properties resemble those of QPOs found recently in the LMXB dippers 4U 1323-62 and EXO 0748-676, which makes 4U 1746-37 the third source known to exhibit this type of QPO. We present evidence for X-ray spectral changes in this source similar to those observed in LMXBs referred to as atoll sources. We detect two states, a lower intensity and spectrally hard state and a higher intensity and spectrally soft state. This may explain the different spectral characteristics reported for 4U 1746-37 earlier. The high-intensity state resembles the banana branch state of atoll sources. The QPOs are seen only in the low-intensity state and are absent when the source is in the banana branch. This strongly suggests that either the accretion disk or an extended central source changes shape between the low-intensity state and the banana branch. Twelve bursts were detected, of which five took place while the source was on the banana branch and seven while the source was in the low-intensity state. The bursts occurring on the banana branch had an e-folding time ~3 times longer than those that occurred in the low-intensity state. Whereas previously detected dips showed a decrease in count rate of only ~15%, we found a dip in one observation for which the count rate dropped from ~200 counts s⁻¹ to ~20 counts s⁻¹. This dip lasted only ~250 s, during which clear spectral hardening occurred. This is the first time strong evidence for spectral changes during a dip have been reported for this source.
publishDate 2000
dc.date.none.fl_str_mv 2000-03-01
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
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/125013
url http://sedici.unlp.edu.ar/handle/10915/125013
dc.language.none.fl_str_mv eng
language eng
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info:eu-repo/semantics/altIdentifier/issn/1538-4357
info:eu-repo/semantics/altIdentifier/doi/10.1086/308471
dc.rights.none.fl_str_mv 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)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
453-457
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instname:Universidad Nacional de La Plata
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reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
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