Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images

In a previous paper, we studied two statistical methods used to analyse the variability of active galactic nuclei (AGNs): the C and F statistics. Applying them to observed differential light-curves of 39 AGNs, we found that, even though the C criterion cannot be considered as an actual statistical t...

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Autores principales: Zibecchi, Lorena, Andruchow, Ileana, Cellone, Sergio Aldo, Carpintero, Daniel Diego
Formato: Articulo Preprint
Lenguaje:Inglés
Publicado: 2020
Materias:
Ciencias Astronómicas
Galaxies: active
Techniques: photometry
Methods: statistical.
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/125195
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-125195
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Galaxies: active
Techniques: photometry
Methods: statistical.
spellingShingle Ciencias Astronómicas
Galaxies: active
Techniques: photometry
Methods: statistical.
Zibecchi, Lorena
Andruchow, Ileana
Cellone, Sergio Aldo
Carpintero, Daniel Diego
Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images
topic_facet Ciencias Astronómicas
Galaxies: active
Techniques: photometry
Methods: statistical.
description In a previous paper, we studied two statistical methods used to analyse the variability of active galactic nuclei (AGNs): the C and F statistics. Applying them to observed differential light-curves of 39 AGNs, we found that, even though the C criterion cannot be considered as an actual statistical test, it could still be a useful parameter to detect variability, whereas F is a good detector of non-variability. In order to test these results under controlled input conditions, so that the different error sources could be individually evaluated, we generated a series of synthetic differential light curves simulating astronomical images with different atmospheric conditions, such as cloud cover, seeing or sky brightness, as well as several types of intrinsic variability of the AGN, all with a specific instrumental configuration. Having obtained light curves for each case, we applied both statistics to them in order to test their reliability. We found that a weight factor should always be used with these indices. The F test has a tendency to classify noisy non-variable curves as variable (i.e. false positives), although it is reliable and robust to correctly classify non-variable curves. On the contrary, although the C index tends to give false negatives, we found that whenever the C index indicates a source to be variable, it effectively is. Finally, light curves with low amplitude variabilities are more likely to be affected by changes in atmospheric conditions.
format Articulo
Preprint
author Zibecchi, Lorena
Andruchow, Ileana
Cellone, Sergio Aldo
Carpintero, Daniel Diego
author_facet Zibecchi, Lorena
Andruchow, Ileana
Cellone, Sergio Aldo
Carpintero, Daniel Diego
author_sort Zibecchi, Lorena
title Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images
title_short Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images
title_full Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images
title_fullStr Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images
title_full_unstemmed Microvariability in AGNs: study of different statistical methods: II. Light curves from simulated images
title_sort microvariability in agns: study of different statistical methods: ii. light curves from simulated images
publishDate 2020
url http://sedici.unlp.edu.ar/handle/10915/125195
work_keys_str_mv AT zibecchilorena microvariabilityinagnsstudyofdifferentstatisticalmethodsiilightcurvesfromsimulatedimages
AT andruchowileana microvariabilityinagnsstudyofdifferentstatisticalmethodsiilightcurvesfromsimulatedimages
AT cellonesergioaldo microvariabilityinagnsstudyofdifferentstatisticalmethodsiilightcurvesfromsimulatedimages
AT carpinterodanieldiego microvariabilityinagnsstudyofdifferentstatisticalmethodsiilightcurvesfromsimulatedimages
bdutipo_str Repositorios
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