Cosmological evolution of quasar radio emission in the view of multifractality
arXiv:1902.05470 · doi:10.3847/1538-4357/ab074e
Abstract
Variations in scaling behavior in the flux and emissions of distant astronomical sources with respect to their cosmic time are important l phenomena that can provide valuable information about the dynamics within the sources and their cosmological evolution with time. Different studies have been applying linear analysis to understand and model quasars' light curves. Here, we study the multifractal behavior of selected quasars' radio emissions in their observed frame (at 22 and 37 GHz bands) and and their rest frame. To this end, we apply the wavelet transform-based multifractal analysis formalism called wavelet transform modulus maxima. In addition, we verify whether the autoregressive integrated moving average (ARIMA) models fit our data or not. In our work, we observe strong multifractal behavior for all the sources. Additionally, we find that the degree of multifractality is strongly similar for each source and significantly different between sources at 22 and 37 GHz. This similarity implies that the two frequencies have the same radiation region and mechanism, whereas the difference indicates that the sources have intrinsically different dynamics. Furthermore, we show that the degree of multifractality is the same in the observed and rest frames of the quasars, i.e., multifractality is an intrinsic property of radio quasars. Finally, we show that the ARIMA models fit the 3C 345 quasar at 22 GHz and partially fit most of the time series with the exception of the 3C 273 and 3C 279 quasars at 37 GHz, for which the models are found to be inadequate.
24 pages, 14 figures, Accepted for publication in The Astrophysical Journal
References in corpus (14)
- Active Galactic Nuclei: what's in a name?
- Correlated Multi-Waveband Variability in the Blazar 3C~279 from 1996 to 2007
- Statistical analyses of long-term variability of AGN at high radio frequencies
- A new activity phase of the blazar 3C 454.3. Multifrequency observations by the WEBT and XMM-Newton in 2007-2008
- Autoregressive Times Series Methods for Time Domain Astronomy
- Three episodes of jet activity in the FRII radio galaxy B0925+420
- Radio bubbles in the composite AGN-starburst galaxy NGC6764
- A peculiar multi-wavelength flare in the Blazar 3C 454.3
- Wavelet analysis of a large sample of AGN at high radio frequencies
- Synchrotron flaring in the jet of 3C 279
- New Suns in the Cosmos III: multifractal signature analysis
- Modelling the multi-wavelength emission of flat spectrum radio quasar 3C 279
- Revealing the nonlinear behaviour of the lensed quasar Q0957+561
- Wavelet transform modulus maxima based fractal correlation analysis