The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity

Autores
Méndez, Mariano R.; Klis, Michiel van der; Ford, Eric C.
Año de publicación
2001
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We study the kilohertz quasi-periodic oscillations (kHz QPOs) in the low-mass X-ray binaries 4U 1728-34, 4U 1608-52, and Aq1 X-1. Each source traces out a set of nearly parallel tracks in a frequency versus X-ray count rate diagram. We find that between two of these tracks, for similar QPO frequency, the 2-60 keV source count rate can differ by up to a factor of ∼4, whereas at the same time the rms amplitude of the kHz QPOs is only a factor of ∼1.1 different. We also find that, for 4U 1608-52 and Aq1 X-1, the rms spectrum of the kHz QPOs does not depend upon which track the source occupies in the frequency versus X-ray count rate diagram. Our results for 4U 1728-34, 4U 1608-52, and Aq1 X-1 are inconsistent with simple "extra source of X-rays" scenarios for the parallel tracks, such as those in which the properties of the kHz QPOs are determined only by the mass accretion rate through the disk, whereas X-ray count rate also depends upon other sources of energy that do not affect the QPOs.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Ciencias Astronómicas
Accretion, accretion disks
Stars: individual (4U 1608-52, 4U 1728-34, Aquila X-1)
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:10915/84694

id SEDICI_7a2aa3617e744aa2b815deec9bd6f2af
oai_identifier_str oai:sedici.unlp.edu.ar:10915/84694
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensityMéndez, Mariano R.Klis, Michiel van derFord, Eric C.Ciencias AstronómicasAccretion, accretion disksStars: individual (4U 1608-52, 4U 1728-34, Aquila X-1)Stars: neutronX-rays: starsWe study the kilohertz quasi-periodic oscillations (kHz QPOs) in the low-mass X-ray binaries 4U 1728-34, 4U 1608-52, and Aq1 X-1. Each source traces out a set of nearly parallel tracks in a frequency versus X-ray count rate diagram. We find that between two of these tracks, for similar QPO frequency, the 2-60 keV source count rate can differ by up to a factor of ∼4, whereas at the same time the rms amplitude of the kHz QPOs is only a factor of ∼1.1 different. We also find that, for 4U 1608-52 and Aq1 X-1, the rms spectrum of the kHz QPOs does not depend upon which track the source occupies in the frequency versus X-ray count rate diagram. Our results for 4U 1728-34, 4U 1608-52, and Aq1 X-1 are inconsistent with simple "extra source of X-rays" scenarios for the parallel tracks, such as those in which the properties of the kHz QPOs are determined only by the mass accretion rate through the disk, whereas X-ray count rate also depends upon other sources of energy that do not affect the QPOs.Facultad de Ciencias Astronómicas y Geofísicas2001info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1016-1026http://sedici.unlp.edu.ar/handle/10915/84694enginfo:eu-repo/semantics/altIdentifier/issn/0004-637Xinfo:eu-repo/semantics/altIdentifier/doi/10.1086/323486info: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:UNLP2025-09-29T11:16:19Zoai:sedici.unlp.edu.ar:10915/84694Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:16:20.071SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
title The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
spellingShingle The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
Méndez, Mariano R.
Ciencias Astronómicas
Accretion, accretion disks
Stars: individual (4U 1608-52, 4U 1728-34, Aquila X-1)
Stars: neutron
X-rays: stars
title_short The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
title_full The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
title_fullStr The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
title_full_unstemmed The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
title_sort The amplitude of the kilohertz quasi-periodic oscillations in 4U 1728-34, 4U 1608-52, and aquila X-1, as a function of X-ray intensity
dc.creator.none.fl_str_mv Méndez, Mariano R.
Klis, Michiel van der
Ford, Eric C.
author Méndez, Mariano R.
author_facet Méndez, Mariano R.
Klis, Michiel van der
Ford, Eric C.
author_role author
author2 Klis, Michiel van der
Ford, Eric C.
author2_role author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
Accretion, accretion disks
Stars: individual (4U 1608-52, 4U 1728-34, Aquila X-1)
Stars: neutron
X-rays: stars
topic Ciencias Astronómicas
Accretion, accretion disks
Stars: individual (4U 1608-52, 4U 1728-34, Aquila X-1)
Stars: neutron
X-rays: stars
dc.description.none.fl_txt_mv We study the kilohertz quasi-periodic oscillations (kHz QPOs) in the low-mass X-ray binaries 4U 1728-34, 4U 1608-52, and Aq1 X-1. Each source traces out a set of nearly parallel tracks in a frequency versus X-ray count rate diagram. We find that between two of these tracks, for similar QPO frequency, the 2-60 keV source count rate can differ by up to a factor of ∼4, whereas at the same time the rms amplitude of the kHz QPOs is only a factor of ∼1.1 different. We also find that, for 4U 1608-52 and Aq1 X-1, the rms spectrum of the kHz QPOs does not depend upon which track the source occupies in the frequency versus X-ray count rate diagram. Our results for 4U 1728-34, 4U 1608-52, and Aq1 X-1 are inconsistent with simple "extra source of X-rays" scenarios for the parallel tracks, such as those in which the properties of the kHz QPOs are determined only by the mass accretion rate through the disk, whereas X-ray count rate also depends upon other sources of energy that do not affect the QPOs.
Facultad de Ciencias Astronómicas y Geofísicas
description We study the kilohertz quasi-periodic oscillations (kHz QPOs) in the low-mass X-ray binaries 4U 1728-34, 4U 1608-52, and Aq1 X-1. Each source traces out a set of nearly parallel tracks in a frequency versus X-ray count rate diagram. We find that between two of these tracks, for similar QPO frequency, the 2-60 keV source count rate can differ by up to a factor of ∼4, whereas at the same time the rms amplitude of the kHz QPOs is only a factor of ∼1.1 different. We also find that, for 4U 1608-52 and Aq1 X-1, the rms spectrum of the kHz QPOs does not depend upon which track the source occupies in the frequency versus X-ray count rate diagram. Our results for 4U 1728-34, 4U 1608-52, and Aq1 X-1 are inconsistent with simple "extra source of X-rays" scenarios for the parallel tracks, such as those in which the properties of the kHz QPOs are determined only by the mass accretion rate through the disk, whereas X-ray count rate also depends upon other sources of energy that do not affect the QPOs.
publishDate 2001
dc.date.none.fl_str_mv 2001
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/10915/84694
url http://sedici.unlp.edu.ar/handle/10915/84694
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-637X
info:eu-repo/semantics/altIdentifier/doi/10.1086/323486
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
1016-1026
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
_version_ 1844616035653648384
score 13.070432