Locating the gamma-ray emission site in Fermi/LAT blazars

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2016
Major/Subject
Mcode
Degree programme
Language
en
Pages
10
171-180
Series
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Volume 456, issue 1
Abstract
In an attempt to constrain and understand the emission mechanism of. gamma-rays, we perform a cross-correlation analysis of 15 blazars using light curves inmillimetre, optical and gamma-rays. We use discrete correlation function and consider only correlations significant at the 99 per cent level. A strong correlation was found between 37 and 95 GHz with a near-zero time delay in most of the sources, and similar to 1 month or longer in the rest. A similar result was obtained between the optical and. gamma-ray bands. Of the 15 sources, less than 50 per cent showed a strong correlation between the millimetre and gamma-ray or millimetre and optical bands. The primary reason for the lack of statistically significant correlation is the absence of a major outburst in the millimetre bands of most of the sources during the 2.5 yr time period investigated in our study. This may indicate that only the long-term variations or large flares are correlated between these bands. The variability of the sources at every waveband was also inspected using fractional rms variability (F-var ). The F-var displays an increase with frequency reaching its maximum in the gamma-rays.
Description
VK: BIBCODE: 2016MNRAS.456..171R; DOI: 10.1093/mnras/stv2653;; eprintid: arXiv:1511.02654
Keywords
galaxies, active-galaxies, jets-galaxies, nuclei-gamma-rays, galaxies-radio continuum, ACTIVE GALACTIC NUCLEI, LARGE-AREA TELESCOPE, EXTRAGALACTIC RADIO-SOURCES, RED-NOISE, OPTICAL CONTINUUM, BRIGHT BLAZARS, LIGHT CURVES, SCALE JET, VARIABILITY, CONNECTION
Other note
Citation
Ramakrishnan , V , Hovatta , T , Tornikoski , M , Nilsson , K , Lindfors , E , Balokovic , M , Lähteenmäki , A , Reinthal , R & Takalo , L 2016 , ' Locating the gamma-ray emission site in Fermi/LAT blazars : II. Multifrequency correlations ' , Monthly Notices of the Royal Astronomical Society , vol. 456 , no. 1 , pp. 171-180 . https://doi.org/10.1093/mnras/stv2653