Svetlana Jorstad

Connection of Gamma-Ray Emission to the mm-Wave VLBI Core in Blazars*Bremen COSPAR 2010

VLBA Monitoring of a Sample of Gamma-Ray Blazars with the Highest Resolution 20 Quasars12 BL Lac objects1 Radio galaxy

http://www.bu.edu/blazarsAlan Marscher & Ivan Agudo

Bremen COSPAR 2010

Kinematics of Parsec Scale Jets*Bremen COSPAR 2010Core - bright stationary feature located at one end of the jet on VLBI image.Moving component knot of enhanced brightness showing a proper motion with respect to the core along the jet direction.

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Gamma-Ray and 43 GHz Core Light Curves*Bremen COSPAR 2010

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Gamma-Ray and 43 GHz Core Variability Indices *Bremen COSPAR 20101. Core Variability Index

(SRmax -max)-(SRmin +min ) Vr =____________________________ (Srmax +max)+(SRmin +min )

SRmax max - maximum observed flux in the 43GHz coreSR min min - minimum observedflux in the 43 GHz core Aller et al. 20032. Gamma-Ray Variability Indexin the case of detection

(Smax -max)-2Smin Vg=____________________________ (Smax +max)+2Smin

Smax max maximum detected -ray flux at 0.1-200 GeVSmin - minimum upper limit for -ray flux observed 3. Gamma-Ray Variability Indexin the case of non-detection

Smax-Smin Vg=___________________ Smax +Smin

Smax maximum upper limit of -ray flux at 0.1-200 GeVSmin - minimum upper limit of -ray flux observed

Bremen COSPAR 2010

Dependence between Vr and Vg*Bremen COSPAR 2010A good correlation between Vg and Vr for the quasars and BL Lac objects. 2. All quasars undetected by the LAT on a weekly basis have low variability index in mm-wave core, Vr 0.6 -ray detection of quasars strongly depends on variability of mm-wave core.3. The BL Lac objects show weaker dependence of -ray emission on activity in mm-wave core.4. Items 2 & 3 imply a possible additional source of -rays in BL Lacs with respect to quasars, which is supported by flatter -ray spectrum of BL Lacs (Abdo et al. 2010).

Bremen COSPAR 2010

Kendall Cross-Correlation Analysis*Bremen COSPAR 20101. The method is applicable for upper and lower limits along with detections.3. Estimate of 43 GHz core flux for each -ray measurement obtained from spline fit to 43 GHz light curve.4. cross-correlation function derived within +/-140 day delay.5. Higher Vr higher max (especially for the quasars). max is significant at 3 level for two BL Lac object (0235+164 & 0716+714) and 7 quasars (0528+134, 1222+216, 3C 273, 1510-089, 1633+382, 3C 345 and 3C 454.3)

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*Bremen COSPAR 2010Flaring Blazars in the Gamma-Ray Sky-126

Kinematics of Parsec Scale Jet of 0235+164 and 1510-089*Bremen COSPAR 2010

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*Bremen COSPAR 2010Kinematics of Parsec Scale Jet of 3C 273

app (c)Smax To (RJD)K1 9.80.43.13456032K2 6.91.40.83473158K3 9.40.68.52491529K410.72.42.81506632K5 9.01.84.26511045K6 6.11.29.65516536K7 ?3.16?5275?

Bremen COSPAR 2010

*Kinematics of Parsec Scale Jet of 1633+382

app 7.82.2 cSmax1.42 JyTo (RJD)509654

Where do -ray Flares Originate in Blazars?*Bremen COSPAR 2010 Trend from Small Statistics:1. Correlation analysis between light curves suggests that -ray flares peak before maximum flux in the mm-wave core with delay in 0-30 day range. 2. Timing of superluminal motion: time of ejection (coincidencebetween the centroids of core & knot) precedes peak of -ray flare by 0-20 days.

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Conclusion*Bremen COSPAR 2010 Analysis of -ray light curves from Fermi LAT data along with contemporaneous VLBA images of the parsec scale jet of blazars shows a tight connection between the mm-wave core and -ray events.2. A significant correlation between the mm-wave core and -ray emission variations is observed if the core undergoes a strong increasein flux, 2 times, which is usually connected with a superluminal knotpassing through the core.These suggest:a. Gamma-rays of blazars originate in their relativistic jets.b. A high -ray state is connected with disturbance(s) propagating down the jet. c. An interaction between a disturbance and the mm-wave VLBA core appears to cause a -ray flare.

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