1999/06/25 by A. Garcia, L. Sodre Jr., L. Sodre +2 · 52 citations
Physics and Astronomy · #Astrometry #Astronomy and Astrophysical Research #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Light curve #Luminosity #Photometry (optics) #Quasar #Redshift #Sigma #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.1999.02884.x
published in Monthly Notices of the Royal Astronomical Society 309(3), 803-816 (Oxford University Press) · 17 pages, 12 figures, accepted for publication in MNRAS (uses MNRAS style)
arxiv created 1999/06/25 · openalex publication_date 1999/11/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present an analysis of quasar variability from data collected during a photometric monitoring of 50 objects carried out at CNPq/Laborat ório Nacional de Astrof ísic á, Brazil, between 1993 March and 1996 July. A distinctive feature of this survey is its photometric accuracy, ∼0.02 V mag, achieved through differential photometry with CCD detectors, which allows the detection of faint levels of variability. We find that the relative variability, δ= σ/L, observed in the V band is anticorrelated with both luminosity and redshift, although we have no means of discovering the dominant relation, given the strong coupling between luminosity and redshift for the objects in our sample. We introduce a model for the dependence of quasar variability on frequency that is consistent with multiwavelength observations of the nuclear variability of the Seyfert galaxy NGC 4151. We show that correcting the observed variability for this effect slightly increases the significance of the trends of variability with luminosity and redshift. Assuming that variability depends only on the luminosity, we show that the corrected variability is anticorrelated with luminosity and is in good agreement with predictions of a simple Poissonian model. The energy derived for the hypothetical pulses, ∼1050 erg, agrees well with those obtained in other studies. We also find that the radio-loud objects in our sample tend to be more variable than the radio-quiet ones, for all luminosities and redshifts.