Variability analysis of AGNs: a review of results using new statistical criteria

ZIBECCHI, LORENA ; ANDRUCHOW, I.; CELLONE, SERGIO A.; ROMERO, GUSTAVO E.; COMBI, JORGE A.

San Juan

Congreso; 54 Reunión Anual de la Asociación Argentina de Astronomía; 2011

We present the re-analysis of the variability results of a sample of active galactic nuclei (AGNs), which have been observed on several occasions with the 2.15 m CASLEO "Jorge Sahade" telescope, San Juan, Argentina, and whose results are published (Romero et al., 1999,AAS, 136, 477; 2000a, AA, 360, 47; 2000b,AJ, 120, 1192; 2002, AA, 390, 431;Cellone et al., 2000 AJ, 119, 1534). The motivation for this new analysis is the implementation, during the last years, of improvements in the statistical criteria applied, taking into account the incidence of the photometric errors (Cellone et al., 2007, MNRAS, 374, 357). This work is framed as a first step in an integral study about the statistical estimators of the variability of AGNs. This study is motivated by the great diversity of statistical tests that have been proposed to analyze the variability of these objects. Since we note that, in some cases, the results of the object variability depend on the test used, we attempt to make a comparative study of the various tests and analyze, under the given conditions, which of them is the most efficient and reliable.