Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303

Autores
Saavedra, Enzo Agustin; Romero, Gustavo Esteban; Bosch Ramon, Valentí; Kefala, Elina
Año de publicación
2023
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We report on the presence of very rapid hard X-ray variability in the γ-ray binary LS I + 61 303. The results were obtained by analysing Nuclear Spectroscopic Telescope Array (NuSTAR) data, which show two achromatic strong flares on ks time-scales before apastron. The Swift/Burst Alert Telescope orbital X-ray light curve is also presented, and the NuSTAR data are put in the context of the system orbit. The spectrum and estimated physical conditions of the emitting region indicate that the radiation is synchrotron emission from relativistic electrons, likely produced in a shocked pulsar wind. The achromaticity suggests that losses are dominated by escape or adiabatic cooling in a relativistic flow, and the overall behaviour in hard X-rays can be explained by abrupt changes in the size of the emitting region and/or its motion relative to the line of sight, with Doppler boosting potentially being a prominent effect. The rapid changes of the emitter could be the result of different situations such as quick changes in the intra-binary shock, variations in the re-accelerated shocked pulsar wind outside the binary, or strong fluctuations in the location and size of the Coriolis shock region. Although future multiwavelength observations are needed to further constrain the physical properties of the high-energy emitter, this work already provides important insight into the complex dynamics and radiation processes in LS I + 61 303.
Fil: Saavedra, Enzo Agustin. Universidad Nacional de La Plata; Argentina
Fil: Romero, Gustavo Esteban. Universidad Nacional de La Plata; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina
Fil: Bosch Ramon, Valentí. Universidad de Barcelona; España
Fil: Kefala, Elina. Universidad de Barcelona; España
Materia
RADIATION MECHANISMS: NON-THERMAL
STARS: NEUTRON
STARS: WINDS, OUTFLOWS
X-RAYS: BINARIES
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/220990

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spelling Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303Saavedra, Enzo AgustinRomero, Gustavo EstebanBosch Ramon, ValentíKefala, ElinaRADIATION MECHANISMS: NON-THERMALSTARS: NEUTRONSTARS: WINDS, OUTFLOWSX-RAYS: BINARIEShttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1We report on the presence of very rapid hard X-ray variability in the γ-ray binary LS I + 61 303. The results were obtained by analysing Nuclear Spectroscopic Telescope Array (NuSTAR) data, which show two achromatic strong flares on ks time-scales before apastron. The Swift/Burst Alert Telescope orbital X-ray light curve is also presented, and the NuSTAR data are put in the context of the system orbit. The spectrum and estimated physical conditions of the emitting region indicate that the radiation is synchrotron emission from relativistic electrons, likely produced in a shocked pulsar wind. The achromaticity suggests that losses are dominated by escape or adiabatic cooling in a relativistic flow, and the overall behaviour in hard X-rays can be explained by abrupt changes in the size of the emitting region and/or its motion relative to the line of sight, with Doppler boosting potentially being a prominent effect. The rapid changes of the emitter could be the result of different situations such as quick changes in the intra-binary shock, variations in the re-accelerated shocked pulsar wind outside the binary, or strong fluctuations in the location and size of the Coriolis shock region. Although future multiwavelength observations are needed to further constrain the physical properties of the high-energy emitter, this work already provides important insight into the complex dynamics and radiation processes in LS I + 61 303.Fil: Saavedra, Enzo Agustin. Universidad Nacional de La Plata; ArgentinaFil: Romero, Gustavo Esteban. Universidad Nacional de La Plata; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Bosch Ramon, Valentí. Universidad de Barcelona; EspañaFil: Kefala, Elina. Universidad de Barcelona; EspañaWiley Blackwell Publishing, Inc2023-10info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/220990Saavedra, Enzo Agustin; Romero, Gustavo Esteban; Bosch Ramon, Valentí; Kefala, Elina; Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303; Wiley Blackwell Publishing, Inc; Monthly Notices of the Royal Astronomical Society; 525; 2; 10-2023; 1848-18550035-8711CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1093/mnras/stad2377info:eu-repo/semantics/altIdentifier/url/https://academic.oup.com/mnras/article-abstract/525/2/1848/7236870?redirectedFrom=fulltextinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T15:37:07Zoai:ri.conicet.gov.ar:11336/220990instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 15:37:07.68CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
title Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
spellingShingle Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
Saavedra, Enzo Agustin
RADIATION MECHANISMS: NON-THERMAL
STARS: NEUTRON
STARS: WINDS, OUTFLOWS
X-RAYS: BINARIES
title_short Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
title_full Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
title_fullStr Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
title_full_unstemmed Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
title_sort Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
dc.creator.none.fl_str_mv Saavedra, Enzo Agustin
Romero, Gustavo Esteban
Bosch Ramon, Valentí
Kefala, Elina
author Saavedra, Enzo Agustin
author_facet Saavedra, Enzo Agustin
Romero, Gustavo Esteban
Bosch Ramon, Valentí
Kefala, Elina
author_role author
author2 Romero, Gustavo Esteban
Bosch Ramon, Valentí
Kefala, Elina
author2_role author
author
author
dc.subject.none.fl_str_mv RADIATION MECHANISMS: NON-THERMAL
STARS: NEUTRON
STARS: WINDS, OUTFLOWS
X-RAYS: BINARIES
topic RADIATION MECHANISMS: NON-THERMAL
STARS: NEUTRON
STARS: WINDS, OUTFLOWS
X-RAYS: BINARIES
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv We report on the presence of very rapid hard X-ray variability in the γ-ray binary LS I + 61 303. The results were obtained by analysing Nuclear Spectroscopic Telescope Array (NuSTAR) data, which show two achromatic strong flares on ks time-scales before apastron. The Swift/Burst Alert Telescope orbital X-ray light curve is also presented, and the NuSTAR data are put in the context of the system orbit. The spectrum and estimated physical conditions of the emitting region indicate that the radiation is synchrotron emission from relativistic electrons, likely produced in a shocked pulsar wind. The achromaticity suggests that losses are dominated by escape or adiabatic cooling in a relativistic flow, and the overall behaviour in hard X-rays can be explained by abrupt changes in the size of the emitting region and/or its motion relative to the line of sight, with Doppler boosting potentially being a prominent effect. The rapid changes of the emitter could be the result of different situations such as quick changes in the intra-binary shock, variations in the re-accelerated shocked pulsar wind outside the binary, or strong fluctuations in the location and size of the Coriolis shock region. Although future multiwavelength observations are needed to further constrain the physical properties of the high-energy emitter, this work already provides important insight into the complex dynamics and radiation processes in LS I + 61 303.
Fil: Saavedra, Enzo Agustin. Universidad Nacional de La Plata; Argentina
Fil: Romero, Gustavo Esteban. Universidad Nacional de La Plata; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina
Fil: Bosch Ramon, Valentí. Universidad de Barcelona; España
Fil: Kefala, Elina. Universidad de Barcelona; España
description We report on the presence of very rapid hard X-ray variability in the γ-ray binary LS I + 61 303. The results were obtained by analysing Nuclear Spectroscopic Telescope Array (NuSTAR) data, which show two achromatic strong flares on ks time-scales before apastron. The Swift/Burst Alert Telescope orbital X-ray light curve is also presented, and the NuSTAR data are put in the context of the system orbit. The spectrum and estimated physical conditions of the emitting region indicate that the radiation is synchrotron emission from relativistic electrons, likely produced in a shocked pulsar wind. The achromaticity suggests that losses are dominated by escape or adiabatic cooling in a relativistic flow, and the overall behaviour in hard X-rays can be explained by abrupt changes in the size of the emitting region and/or its motion relative to the line of sight, with Doppler boosting potentially being a prominent effect. The rapid changes of the emitter could be the result of different situations such as quick changes in the intra-binary shock, variations in the re-accelerated shocked pulsar wind outside the binary, or strong fluctuations in the location and size of the Coriolis shock region. Although future multiwavelength observations are needed to further constrain the physical properties of the high-energy emitter, this work already provides important insight into the complex dynamics and radiation processes in LS I + 61 303.
publishDate 2023
dc.date.none.fl_str_mv 2023-10
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
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://hdl.handle.net/11336/220990
Saavedra, Enzo Agustin; Romero, Gustavo Esteban; Bosch Ramon, Valentí; Kefala, Elina; Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303; Wiley Blackwell Publishing, Inc; Monthly Notices of the Royal Astronomical Society; 525; 2; 10-2023; 1848-1855
0035-8711
CONICET Digital
CONICET
url http://hdl.handle.net/11336/220990
identifier_str_mv Saavedra, Enzo Agustin; Romero, Gustavo Esteban; Bosch Ramon, Valentí; Kefala, Elina; Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303; Wiley Blackwell Publishing, Inc; Monthly Notices of the Royal Astronomical Society; 525; 2; 10-2023; 1848-1855
0035-8711
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1093/mnras/stad2377
info:eu-repo/semantics/altIdentifier/url/https://academic.oup.com/mnras/article-abstract/525/2/1848/7236870?redirectedFrom=fulltext
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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