Workshop on Blazar Variability across the Electromagnetic Spectrum

It has been known for a long time that blazars are variable, both on short (minutes to days) and long (weeks to years) timescales. Various models exist to explain the mechanisms causing variability, and disentangling them has also been particularly hard. A wide variety of tools are used to define and characterize variability, with varying limitations depending on the analysis method and observation uniformity. We plan to have several wavelength-dependent review talks about variability of blazars, ranging from radio to Very High Energy wavelengths, with a special emphasis on Atmospheric Cherenkov Telescope results - and possibly from GLAST - where the timescales have been the shortest. A better view of their fluctuations and power spectra, flare asymmetries in lightcurves, their possible intrinsic or extrinsic origin, as well as different talks on analysis methods strengths and limitations. The main objective of the meeting is to have a view across the spectrum of what the relevant characteristics are (timescales, power distributions), their correlations, the caveats of their assessment, and what underlying physics can realistically be probed with the current generation of instruments.

Sessions
Session1: The blazar paradigm
Session 2: The soft side
Session 3: The hard side
Session 4: Analysis tools
Session 5: Mechanisms at play and their inherent variability
Session 6: Future instruments and measurements
Poster

Session1: The blazar paradigm
Blazars: the broadband observational point of view PoS(BLAZARS2008)001 A. Celotti
Implications of VHE emission in Gamma-Ray AGN PoS(BLAZARS2008)002 pdf A. Levinson
Pair cascades in AGN PoS(BLAZARS2008)003 J. Poutanen
Can short variability time scales be reconciled with hadronic emission PoS(BLAZARS2008)004 K. Mannheim
Session 2: The soft side
VLBA observations of Blazars PoS(BLAZARS2008)005 pdf S.G. Jorstad
VLBI polarisation variability and implications for jet models PoS(BLAZARS2008)006 D. Gabuzda
Total intensity radio variations in blazars PoS(BLAZARS2008)007 pdf E. Valtaoja
Variability of blazars in the IR-optical-UV energy bands: observational facts PoS(BLAZARS2008)008 G. Tosti
Thermal AGN signatures in blazars PoS(BLAZARS2008)009 pdf E. Perlman
Session 3: The hard side
Long-term X-ray variability in Blazars and its multiwaveband context PoS(BLAZARS2008)010 pdf A. Marscher
GeV gamma-ray variability PoS(BLAZARS2008)011 J. McEnery
Variability of VHE gamma-ray blazars PoS(BLAZARS2008)012 W. Benbow
TeV/X-ray correlated variability in blazars (optical, radio) PoS(BLAZARS2008)013 pdf R. Wagner
Session 4: Analysis tools
Explaining X-ray Variability in Blazars PoS(BLAZARS2008)014 pdf I. McHardy
Characterizing X-ray variability of blazars PoS(BLAZARS2008)015 pdf J. Kataoka
The emission of blazars in VHE gamma-rays viewed as a random stationary process: the case of PKS 2155-304 PoS(BLAZARS2008)016 pdf B. Degrange
Session 5: Mechanisms at play and their inherent variability
Particle acceleration, shocks, reconnection... PoS(BLAZARS2008)017 J. Kirk
A unified time-dependent view of relativistic jets PoS(BLAZARS2008)018 G. Henri
Multiwavelength synchrotron/Compton spectral analysis of TeV blazars and FSRQs: a new approach PoS(BLAZARS2008)019 pdf C. Dermer
Radiative outputs of blazars PoS(BLAZARS2008)020 R. Moderski
Variability and propagation effects PoS(BLAZARS2008)021 S. Wagner
Unification scenarios: the case of M87 PoS(BLAZARS2008)022 pdf H. Sol
Session 6: Future instruments and measurements
The next generation of X-ray sensitive observatories and their potential for blazar variability studies PoS(BLAZARS2008)023 G. Madejski
Strengths and limitations of Atmospheric Cherenkov Telescopes (ACTs) - Present and Future - for transient VHE sources PoS(BLAZARS2008)024 M. Punch
What have we learned? Outstanding questions... PoS(BLAZARS2008)025 pdf P. Kaaret
Poster
ESO VLT optical spectroscopy of BL Lac objects PoS(BLAZARS2008)026 pdf A. Treves
Probing the Jet Physics of TeV Blazars PoS(BLAZARS2008)027 pdf U. Barres de Almeida
M87 PoS(BLAZARS2008)028 pdf K. Berger, D. Mazin, D. Tescaro and R. Wagner
Multi band optical micro variability of BL Lac objects PoS(BLAZARS2008)029 pdf E.P. Christopoulou, E.M. Xilouris, P. Boumis and I.E. Papadakis
OJ 287 colors during a multifrequency campaign PoS(BLAZARS2008)030 pdf S. Ciprini
L Band (20cm) Radio Analysis of WARPS Galaxy Clusters PoS(BLAZARS2008)031 C. Coffey
Optical Variability Monitoring for Gamma ray Blazars: preliminary results PoS(BLAZARS2008)032 pdf J.A. Combi, I. Andruchow, S.A. Cellone, G.E. Romero, J. Martí, A. Munoz- Arjonilla and J. Sanchez-Sutil
AGILE detection of a strong gamma ray flare from the blazar S5 0716 714 during September-October 2007 PoS(BLAZARS2008)033 pdf F. D'Ammando, A.W. Chen, M. Villata, C.M. Raiteri, V. Vittorini, A. Bulgarelli, I. Donnarumma, A. Giuliani, F. Longo, L. Pacciani, G. Pucella, M. Tavani and S. Vercellone
injection of electron with red noise light curve PoS(BLAZARS2008)034 pdf D. Sanchez
Optical polarization variability in TeV BL Lacs PoS(BLAZARS2008)035 pdf T. Dominici, Z. Abraham, A. Pereyra and A.M. Magalhães
Multi wavelenth observations of PG 1553 113 PoS(BLAZARS2008)036 pdf attachments D. Dorner
Infrared polarimetry of 3C454 3 during a flare PoS(BLAZARS2008)037 pdf G. Dubus and S. Chaty
The nonlinear long term X ray variability of Mrk 421 PoS(BLAZARS2008)038 pdf D. Emmanoulopoulos
The AGN Monitoring Program with the Whipple 10m Observatory PoS(BLAZARS2008)039 pdf L. Fortson and J. Kildea
Variability on Decaparsec scales of a number of BL Lac objects PoS(BLAZARS2008)040 pdf R. Hallahan and D. Gabuzda
Long term radio variability of AGN PoS(BLAZARS2008)041 pdf T. Hovatta, M. Tornikoski, H.J. Lehto, E. Nieppola, E. Valtaoja, M. Lainela, I. Torniainen, A. Lahteenmaki, M.F. Aller and H.D. Aller
Observations of blazars by the ESA INTEGRAL satellite PoS(BLAZARS2008)042 pdf R. Hudec
VRIJHK photometry of PKS 0537-441 and PKS 2155-304 in 2006-2008 PoS(BLAZARS2008)043 pdf D. Impiombato
X ray spectral variability of TeV Blazars PoS(BLAZARS2008)044 pdf S. Kaufmann and S. Wagner
The ten years optical study of ESS and TeV samples of BL Lacertae objects PoS(BLAZARS2008)045 O. Kurtanidze
discovery of VHE gamma rays from RGB J0152 017 PoS(BLAZARS2008)046 pdf J.P. Lenain, D. Nedbal, M. Raue, S. Kaufmann, L. Gerard, M. Hauser and B. Giebels
Optically Triggered Target of Opportunity Observations with the MAGIC Telescope PoS(BLAZARS2008)047 pdf E. Lindfors
Roma BZCAT: a Multifrequency Blazar catalogue PoS(BLAZARS2008)048 pdf A. Maselli
The Timescales of the Optical Variability of 3C454 3 PoS(BLAZARS2008)049 H.R. Miller
Stability of magnetized spine sheath relativistic jets PoS(BLAZARS2008)050 pdf Y. Mizuno
Blazar sequence: the effect of Doppler correction PoS(BLAZARS2008)052 pdf E. Nieppola
Radiation from relativistic jets PoS(BLAZARS2008)053 pdf K.I. Nishikawa and Y. Mizuno
Observation of Gamma Ray Variability of 3C 273 with AGILE during the MWL campaign of Dec 2007 PoS(BLAZARS2008)054 pdf L. Pacciani, I. Donnarumma, V. Vittorini, F. D'Ammando, G. Pucella, M. Tavani, D. Impiombato, M.T. Fiocchi, G. Stratta, F. Verrecchia, A. Bulgarelli, A. Chen, A. Giuliani, S. Vercellone, F. Longo, G. Barbiellini, M. Feroci, E. Costa, P. Soffitta, E. Del Monte, Y. Evangelista, F. Lazzarotto, I. Lapshov, M. Rapisarda and G. Di Cocco
Last results from the WEBT and GASP PoS(BLAZARS2008)055 pdf C.M. Raiteri and M. Villata
XMM Newton Observations of Low Energy Peaked BL Lac Objects PoS(BLAZARS2008)056 pdf J. Randall
VERITAS Observations of Mrk 421 with Simultaneous Coverage in the X ray Band PoS(BLAZARS2008)057 pdf L. Reyes
Possible variability signatures of Supermassive Binary Black Holes in Blazars PoS(BLAZARS2008)058 pdf F.M. Rieger
Swift Observations of emission line radio loud AGN PoS(BLAZARS2008)059 R. Sambruna
Multicolor polarimetric observation of 15 min variability in S5 0716 714 PoS(BLAZARS2008)060 pdf M. Sasada
Suzaku observation of TeV blazar 1ES 1218 304: clues on particle acceleration in an extreme TeV blazar PoS(BLAZARS2008)061 pdf R. Sato
Large amplitude intraday variability in 1156 295 observed during a VLBI experiment PoS(BLAZARS2008)062 pdf T. Savolainen and Y.Y. Kovalev
Suzaku observation of the OJ 287, Quiescence and Predicted flare in 2007 PoS(BLAZARS2008)063 pdf H. Seta
Mkn 501 Binary black holes as source of Variability PoS(BLAZARS2008)064 F. Spanier
Lobster Eye X ray Monitor and Blazars PoS(BLAZARS2008)065 pdf I. Sujova
Temporal Variability Study of the BL Lac object PKS2155 304 with H E S S PoS(BLAZARS2008)066 pdf G. Superina
Hard X ray observation of Fornax A west lobe with Suzaku PoS(BLAZARS2008)067 M. Tashiro
A time dependent inhomogeneous stratified jet model applied to TeV blazar PKS 2155 304 PoS(BLAZARS2008)068 B. Timothé
Longterm multi wavelength variability of 3C 273 PoS(BLAZARS2008)069 pdf M. Turler, S. Soldi, S. Paltani and T.J.L. Courvoisier
Simultaneous optical infrared polarimetry of blazars with TRISPEC/KANATA PoS(BLAZARS2008)070 pdf M. Uemura
Modelling the Delayed Emission in the 2005 Mkn 501 Flare PoS(BLAZARS2008)071 pdf R. Wagner and W. Bednarek
The Perugia variability monitoring of blazars PoS(BLAZARS2008)072 pdf S. Ciprini
Analytical and numerical time-dependent modelling of SSC blazars variability PoS(BLAZARS2008)073 pdf S. Ciprini
Long term VHE gamma ray monitoring of bright blazars with a dedicated Cherenkov telescope PoS(BLAZARS2008)074 pdf T. Bretz, M. Backes, I. Braun and D. Dorner
The International High Energy Astrophysics Multiwavelength Coordination Wiki PoS(BLAZARS2008)075 L. Fortson
Very long term observations of blazars candidates for supermassive black hole binaries PoS(BLAZARS2008)076 pdf R. Hudec
Multifrequency observation of VLBL objects PoS(BLAZARS2008)077 pdf A. Maselli