Optical Outburst of the Blazar S4 0954+658 in Early 2015

We analyze the behavior of the BL Lac object S4 0954+658 during an unprecedented bright optical flare in early 2015. The optical flare was accompanied by a powerful γ -ray flare and the detection of very-high-energy γ -ray emission. We analyze total and polarized intensity images obtained with the VLBA at 43 GHz and discover a new bright polarized superluminal knot, which was ejected from the VLBI-core during the peak of the flare.

[1]  J. Binney,et al.  Galaxies , 2019, Foundations of Astrophysics.

[2]  Yasuyuki T. Tanaka,et al.  A significant hardening and rising shape detected in the MeV/GeV νFν spectrum from the recently discovered very-high-energy blazar S4 0954+65 during the bright optical flare in 2015 February , 2016, 1604.05427.

[3]  D. Blinov,et al.  Optical variability of the blazar S4 0954+658 in 2008–2012 , 2015 .

[4]  J. Aleksic,et al.  Discovery of Very High Energy Gamma-Ray Emission from the FSRQ S4 0954+65 with the MAGIC telescopes , 2015 .

[5]  R. Mirzoyan.  Discovery of Very High Energy Gamma-Ray Emission from the FSRQ S4 0954+65 with the MAGIC telescopes , 2015 .

[6]  Inst. de Astrof'isica de Andaluc'ia,et al.  THE OUTBURST OF THE BLAZAR S4 0954+658 IN 2011 MARCH–APRIL , 2014, 1406.2286.

[7]  A. Falcone,et al.  SWIFT X-RAY TELESCOPE MONITORING OF FERMI-LAT GAMMA-RAY SOURCES OF INTEREST , 2013, 1305.4949.

[8]  K. Grainge,et al.  BLAZARS IN THE FERMI ERA: THE OVRO 40 m TELESCOPE MONITORING PROGRAM , 2010, 1011.3111.

[9]  J. Chiang,et al.  THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION , 2009, 0902.1089.

[10]  P. Giommi,et al.  Results of WEBT, VLBA and RXTE monitoring of 3C 279 during 2006-2007 ⋆ , 2008, 0810.4261.

[11]  M. Gurwell,et al.  Monitoring Phase Calibrators at Submillimeter Wavelengths , 2007 .

[12]  Paul S. Smith,et al.  Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array , 2005, astro-ph/0502501.

[13]  Jet Stability and the Generation of Superluminal and Stationary Components , 2001, astro-ph/0101188.

[14]  C. Raiteri,et al.  Optical and radio behaviour of the blazar S4 0954+65 , 1999 .