An Intermediate State of Cygnus X-1
- Autores
- Belloni, Tomaso; Méndez, Mariano R.; Klis, M. van der; Hasinger, Günther; Lewin, Walter H. G.; Paradijs, J. van
- Año de publicación
- 1996
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- We report RXTE/PCA observations of the black hole candidate Cygnus X-1. In 1996 February the source was in its usual "low" state. In three observations during 1996 May the source was on average brighter by a factor of 2 and showed less rapid variability and a softer energy spectrum. However, the observations indicate that Cyg X-1 did not enter a high state like the one observed in black hole transients. Flux, variability, and spectral shape suggest instead that the source was in an "intermediate" state similar to what has been observed in GS 1124-68 and GX 339-4. Perhaps also the state transitions of Cyg X-1 observed in the 1970s were not to a high state but to this intermediate state.
Facultad de Ciencias Astronómicas y Geofísicas - Materia
-
Ciencias Astronómicas
X-rays: stars
stars: individual (Cygnus X-1) - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
.jpg)
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/123556
Ver los metadatos del registro completo
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An Intermediate State of Cygnus X-1Belloni, TomasoMéndez, Mariano R.Klis, M. van derHasinger, GüntherLewin, Walter H. G.Paradijs, J. vanCiencias AstronómicasX-rays: starsstars: individual (Cygnus X-1)We report RXTE/PCA observations of the black hole candidate Cygnus X-1. In 1996 February the source was in its usual "low" state. In three observations during 1996 May the source was on average brighter by a factor of 2 and showed less rapid variability and a softer energy spectrum. However, the observations indicate that Cyg X-1 did not enter a high state like the one observed in black hole transients. Flux, variability, and spectral shape suggest instead that the source was in an "intermediate" state similar to what has been observed in GS 1124-68 and GX 339-4. Perhaps also the state transitions of Cyg X-1 observed in the 1970s were not to a high state but to this intermediate state.Facultad de Ciencias Astronómicas y Geofísicas1996-12-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfL107-L110http://sedici.unlp.edu.ar/handle/10915/123556enginfo:eu-repo/semantics/altIdentifier/issn/0004-637Xinfo:eu-repo/semantics/altIdentifier/doi/10.1086/310369info: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:UNLP2025-10-22T17:10:09Zoai:sedici.unlp.edu.ar:10915/123556Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-22 17:10:09.509SEDICI (UNLP) - Universidad Nacional de La Platafalse |
| dc.title.none.fl_str_mv |
An Intermediate State of Cygnus X-1 |
| title |
An Intermediate State of Cygnus X-1 |
| spellingShingle |
An Intermediate State of Cygnus X-1 Belloni, Tomaso Ciencias Astronómicas X-rays: stars stars: individual (Cygnus X-1) |
| title_short |
An Intermediate State of Cygnus X-1 |
| title_full |
An Intermediate State of Cygnus X-1 |
| title_fullStr |
An Intermediate State of Cygnus X-1 |
| title_full_unstemmed |
An Intermediate State of Cygnus X-1 |
| title_sort |
An Intermediate State of Cygnus X-1 |
| dc.creator.none.fl_str_mv |
Belloni, Tomaso Méndez, Mariano R. Klis, M. van der Hasinger, Günther Lewin, Walter H. G. Paradijs, J. van |
| author |
Belloni, Tomaso |
| author_facet |
Belloni, Tomaso Méndez, Mariano R. Klis, M. van der Hasinger, Günther Lewin, Walter H. G. Paradijs, J. van |
| author_role |
author |
| author2 |
Méndez, Mariano R. Klis, M. van der Hasinger, Günther Lewin, Walter H. G. Paradijs, J. van |
| author2_role |
author author author author author |
| dc.subject.none.fl_str_mv |
Ciencias Astronómicas X-rays: stars stars: individual (Cygnus X-1) |
| topic |
Ciencias Astronómicas X-rays: stars stars: individual (Cygnus X-1) |
| dc.description.none.fl_txt_mv |
We report RXTE/PCA observations of the black hole candidate Cygnus X-1. In 1996 February the source was in its usual "low" state. In three observations during 1996 May the source was on average brighter by a factor of 2 and showed less rapid variability and a softer energy spectrum. However, the observations indicate that Cyg X-1 did not enter a high state like the one observed in black hole transients. Flux, variability, and spectral shape suggest instead that the source was in an "intermediate" state similar to what has been observed in GS 1124-68 and GX 339-4. Perhaps also the state transitions of Cyg X-1 observed in the 1970s were not to a high state but to this intermediate state. Facultad de Ciencias Astronómicas y Geofísicas |
| description |
We report RXTE/PCA observations of the black hole candidate Cygnus X-1. In 1996 February the source was in its usual "low" state. In three observations during 1996 May the source was on average brighter by a factor of 2 and showed less rapid variability and a softer energy spectrum. However, the observations indicate that Cyg X-1 did not enter a high state like the one observed in black hole transients. Flux, variability, and spectral shape suggest instead that the source was in an "intermediate" state similar to what has been observed in GS 1124-68 and GX 339-4. Perhaps also the state transitions of Cyg X-1 observed in the 1970s were not to a high state but to this intermediate state. |
| publishDate |
1996 |
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1996-12-01 |
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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/10915/123556 |
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eng |
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eng |
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info:eu-repo/semantics/altIdentifier/issn/0004-637X info:eu-repo/semantics/altIdentifier/doi/10.1086/310369 |
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