in cooperation with: E. Kun1, Gabányi, K. É1, J. Roland2, S.J. Qian3, M. Brockamp4, A. Eckart5, C. Lämmerzahl6,7, R. Malchow4, H. Aller8, M. Aller8, M. Karouzos9,B. Gong, L.A. Gergely1, T.P. Krichbaum4, C. Fromm4, A. Zensus4, A. Witzel4, et al. 1 Uni. Szeged ,2 IAP Paris, 3 Beijing Observatory, 4 MPIfR Bonn, 5 Uni Köln, 6 Uni Bremen, 7 Uni Oldenburg, 8 Uni. Michigan, 9 Seoul National Uni. Priv.-Doz. Dr. Silke Britzen Max Planck Institute for Radio Astronomy Bonn, Germany 1 3 N.#Tacken# Resolution by Very Long Baseline Interferometry (VLBI) 4 Virtual Telescope with earth-like diameter Highest angular resolution in astronomy Satellite rotation about 9.5 days apogee radius: 310 000 -390 000 km currently highest resolution with space-antenna What VLBI can do for you … 6 Many questions remain: - what powers jets? Black Hole spin or disk? - what are jets made off? - one black hole or two? What happens in a binary? - how do we proof black holes? Event Horizon Telescope W. Steffen (UNAM) Leptonic Blazar Model Synchrotron Injection, emission acceleration of Relativistic jet outflow with Γ ≈ 10 ultrarelativistic electrons ν$ F ν ,t) ,t) γ γ-q ( e ν Q γ Compton γ1$ γ2$ emission Radiative cooling ν$ ↔ escape => F ν -q or -2 ,t) ,t) γ γ γ -(q+1) ν ( e γ Seed photons: Q Synchrotron (within same region [SSC] or γ γ1$ γb γ2$ γb: slower/faster earlier/later emission regions τ (γ ) = τ γb γ1 γ2$ cool b esc [decel. jet]), Accr. Disk, BLR, dust torus (EC) adapted from M. Böttcher Hadronic Blazar Models Proton-induced Injection, Relativistic jet outflow acceleration of radiation mechanisms: with Γ ≈ 10 ultrarelativistic electrons and ν$ F protons ν ,t) ,t) γ γ-q ν ( e,p • Proton Q synchrotron γ γ1$ γ2$ • pγ → pπ0 π0 → 2γ$ Synchrotron • pγ → nπ+ ; π+ → µ+ν $ emission of µ + + primary e- µ → e νeνµ$ ν$ → secondary µ-, F ν e-synchrotron • Cascades … ν adapted from M. Böttcher Leptonic and Hadronic Model Fits to Blazar SEDs 3C66A (IBL) Red = leptonic Green = lepto-hadronic Abdo et al. (2011: ApJ, 726, 43), Böttcher 2011 Paradigm 1: High apparent radial superluminal motion 3C 120, Gomez et al. Gomez et al. 2003 Separationthecore from Time Paradigm 2: Component ejection The standard idea: Black hole is fed and part of the plasma is seen as component ejection 3C120 Marscher et al., 2002 similar to Microquasar GRS 1915+105 Lobanov & Roland 14 BL Lac Objects – no apparent superluminal motion in radial direction 1749+701, z=0.77 1803+784, z=0.68 Roland, Britzen et al. 2013A&A,557, 85 1749+701 0716+714 z>0.3 2010A&A...511A..57B Kun et al. 2015 Britzen et al. 2015 …. and no component ejection from the core 2009A&A, 508,1205 Britzen et al. 2010, Kun et al. 2015 Alfvén wrote in a letter to the journal Nature in 1942: "If a conducting liquid is placed in a constant magnetic field, every motion of the liquid gives rise to an E.M.F. which produces electric currents. Owing to the magnetic field, these currents give mechanical forces which change the state of motion of the liquid. Thus a kind of combined electromagnetic-hydrodynamic wave is produced." https://www.youtube.com/watch?v=k3d9CBh5tQQ Cohen et al. 2015 thinking in terms of Alfvén waves and not in terms of components Cartoon of an Alfven S- wave traveling down an astrophysical jet. The jet is a conical plasma flow launched by a black hole, with a helical magnetic field (yellow coil) permeating the plasma. The wave then travels along the jet, in the direction of the plasma flow, but at a velocity determined by both the jet¹s magnetic properties and the plasma flow speed. The BL Lac jet is several light years long, and the actual wave speed is about 98% the speed of light. Lance Hayashida/Caltech BL Lac Object 0735+178 – what‘s that ??? Quasar or Bl Lac Object? Britzen et al. 2010,A&A515, 105 In a binary black hole system, the directions of the spin angular momentum of each black hole (red cone arrows) and of the orbital angular momentum for the system (blue cone arrow) change, or precess, over time. Graphic by Midori Kitagawa We identify the linear trends in the variations as due to the slow reorientation of the spin of the jet emitter black hole induced by the spin-orbit precession and we determine the precession period TSO=4852+/-646 yr of the more massive black hole, acting as the jet emitter. … for the first time evidence from VLBI jet kinematics, for the spinning nature of the jet-emitting black hole. Kun et al., 2014, MNRAS, 445, 1370 Supermassive Binary Black Holes crucial with regard to cosmological evolution and activity of galaxies optical X-ray optical NASA/CXC/MPE/S. Komossa et al. VLBI VLA gravitational wave emission? Hardcastle et al. 1996 LoustoMurgia et & al. Healy 2015 23 Zooming in: Stellar Orbits in the Central Parsec 2#light?days# 4#Million#solar#masses## Black#Hole# SgrA*# 6#RS# RS#~#10#µas# Ghez#et#al.#2008,#Gillessen#et#al.#2009a,b# Earth#orbit#diameter# Black#Hole#Shadow# Photon sphere causes shadow Bardeen#(1973);#Dexter#&#Agol#(2009)# 28# adapted from T. Krichbaum Event Horizon Telescope Krichbaum Event Horizon Telescope – > -> -> Imaging the Photon Sphere Bardeen#(1973);#Dexter#&#Agol#(2009)# Broderick#&#Loeb#(2009)# …##calcUlate#images#oVer#a#grid#of#parameters,## and#the#Video#shows#one#simUlaYon#at#different## inclinaYon#angles.#Edge?on,#Doppler#beaming# #is#the#most#important#effect.#Towards## face?on,#the#image#necessarily#becomes#more## circUlarly#symmetric#and#the#shadow#becomes## more#prominent.## 100x100 µas Dexter et al. (2009, 2010) Falcke,#Melia#&#Agol#(2000)# Bromley,#Melia#&#Liu#(2001)# 32# Sgr#A*#Black#Hole#Shadow# !100 µas" 230 GHz !104 km " Shadow 345 GHz Shadow#may#be#detected# on#Chile?Mexico#baseline# (in#closUre#phase#too)# 33# Dexter & Fragile 2011, 2012 Krichbaum et al. 2014 Krichbaum et al. 2014 36 What VLBI can do for you … 37 38 Krichbaum et al. http://www.perimeterinstitute.ca/conferences/eht-2014 .