Extremely violent optical microvariability in blazars: Fact or fiction?

Variability amplitudes larger than 1 mag over time-scales of a few tens of minutes have recently been reported in the optical light curves of several blazars. In order to independently verify the real occurrence of such extremely violent events, we undertook an observational study of a selected samp...

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Detalhes bibliográficos
Autores: Cellone, Sergio Aldo, Romero, Gustavo Esteban, Araudo, Anabella Teresa
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2006
País:Argentina
Recursos:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/83045
Acesso em linha:http://sedici.unlp.edu.ar/handle/10915/83045
Access Level:acceso abierto
Palavra-chave:Ciencias Astronómicas
BL Lacertae objects: general
Galaxies: active
Galaxies: photometry
Descrição
Resumo:Variability amplitudes larger than 1 mag over time-scales of a few tens of minutes have recently been reported in the optical light curves of several blazars. In order to independently verify the real occurrence of such extremely violent events, we undertook an observational study of a selected sample of three blazars: PKS 0048-097, PKS 0754+100 and PKS 1510-089. Possible systematic error sources during data acquisition and reduction were carefully evaluated. We indeed found flux variability at intra-night time-scales in all the three sources, although no extremely violent behaviour, as reported by other authors, was detected. We show that an incorrect choice of the stars used for differential photometry will, under fairly normal conditions, lead to spurious variability with large amplitudes on short time-scales. Wrong results of this kind can be avoided with the use of simple error-control techniques.