Diversity of gamma-ray and Radio Variabilities of Bright Blazars and Implications for gamma-ray Emission Location. (arXiv:2003.11175v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_H/0/1/0/all/0/1">Hai-Ming Zhang</a> (NJU), <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_Z/0/1/0/all/0/1">Zhen-Jie Wang</a> (GXU), <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_J/0/1/0/all/0/1">Jin Zhang</a> (NAOC), <a href="http://arxiv.org/find/astro-ph/1/au:+Yi_T/0/1/0/all/0/1">Ting-Feng Yi</a> (YNNU), <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_L/0/1/0/all/0/1">Liang Chen</a> (SHAO), <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_R/0/1/0/all/0/1">Rui-Jing Lu</a> (GXU), <a href="http://arxiv.org/find/astro-ph/1/au:+Liang_E/0/1/0/all/0/1">En-Wei Liang</a> (GXU)

Violent multi-wavelength variabilities are observed in gamma-ray-selected
blazars. We present an analysis of long-term light curves for eight bright
blazars to explore the co-variation pattern in the gamma-ray and radio bands.
We extract their gamma-ray light curves and spectra with data observed by the
Fermi/LAT since 2008. We find diverse co-variation patterns between the
gamma-ray and radio (at 43 GHz) fluxes in these sources. The gamma-ray and
radio fluxes of 3C 454.3 and PKS 1633+382 are correlated without any time-lag,
suggesting that they are from the same radiation region. Similar correlation is
also observed in 3C 273 and PKS 1222+216, but the radio flux is lag behind the
gamma-ray flux approximately ~160 days and ~290 days, respectively. This likely
suggests that their gamma-ray emission regions are located at the upstream of
their radio cores at 43 GHz. The gamma-ray and radio fluxes of the other four
blazars are not correlated, implying that the gamma-ray and radio emission may
be from different regions in their jets. The gamma-ray light curves of the
eight blazars can be decomposed into some long timescale variability components
and fast spike flares. We propose that they may be attributed to the central
engine activity and the magnetic reconnection process or turbulence in the
local emission region, respectively.

Violent multi-wavelength variabilities are observed in gamma-ray-selected
blazars. We present an analysis of long-term light curves for eight bright
blazars to explore the co-variation pattern in the gamma-ray and radio bands.
We extract their gamma-ray light curves and spectra with data observed by the
Fermi/LAT since 2008. We find diverse co-variation patterns between the
gamma-ray and radio (at 43 GHz) fluxes in these sources. The gamma-ray and
radio fluxes of 3C 454.3 and PKS 1633+382 are correlated without any time-lag,
suggesting that they are from the same radiation region. Similar correlation is
also observed in 3C 273 and PKS 1222+216, but the radio flux is lag behind the
gamma-ray flux approximately ~160 days and ~290 days, respectively. This likely
suggests that their gamma-ray emission regions are located at the upstream of
their radio cores at 43 GHz. The gamma-ray and radio fluxes of the other four
blazars are not correlated, implying that the gamma-ray and radio emission may
be from different regions in their jets. The gamma-ray light curves of the
eight blazars can be decomposed into some long timescale variability components
and fast spike flares. We propose that they may be attributed to the central
engine activity and the magnetic reconnection process or turbulence in the
local emission region, respectively.

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