Ejected Superluminal Features Associated with the VHE Flare in AGN Jets: Sites Constrained by SMBHs

Image credit: W. B. Sparks (STScI) Masanori Nakamura (ASIAA)

Collaborators: K. Asada (ASIAA), J. A. Biretta (STScI), D. A. Garofalo (CSUN), C. A. Norman (JHU), D. L. Meier (JPL), W. B. Sparks (STScI)

TIARA WS on Transient Universe, Dec. 2011, NTHU Outline

✤ Evidence for magnetic acceleration & collimation M87 of the active galactic nuclei (AGN) jet in M87

✤ Quad MHD shock model for sub/super-luminal ejections

✤ Stationary feature in AGN jets constrained by the SMBH

✤ ASIAA “Greenland Telescope Project”: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets Outline

✤ Evidence for magnetic acceleration & collimation of the active galactic nuclei (AGN) jet in M87

✤ Quad MHD shock model for sub/super-luminal ejections

✤ Stationary feature in AGN jets constrained by the SMBH

✤ ASIAA “Greenland Telescope Project”: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets Observational Overview Observations • Good Resolution • Nearby: D 16 Mpc (1 mas = 0.08 pc) ∼ • FR I: Misaligned BL Lac (θ 14 ◦ ; Wang & Zhou 2009) view ∼ • SMBH mass: (6 . 6 0 . 4) 10 9 M (Gebhardt et al. 2011) ± × ⊙ • VLBA resolution: 20 RS at 43 GHz

• Sub-mm VLBI resolution: 3 RS at 345 GHz (w/ GL)

VLBA Movie at 43GHz (C. Walker, NRAO)

• Well studied at wavelengths from radio to X-ray • Proper motions (sub/super-luminal feature) • Polarization (20-60%; ordered B-fields) • Substructure (limb-brightened, knots, wiggles, ...), indicating a role of B-fields • In situ particle acceleration (Fermi-I diffusive shock process )

HST Movie (J. Biretta, STScI) Observations (cont.)

X-ray: XMM-Newton M87 M87

Forman et al. (2005)

Radio: VLA M87

Image credit: X-ray (NASA/CXC/KIPAC/N. Werner, E. Million et al); Radio (NRAO/ AUI/NSF/F. Owen)

• Transferring the enormous energy in the nucleus Owen et al. (2000) on the circumgalactic environment (from 10-3 to 105 parsec) Superluminal Motions

Biretta et al. (1995, 1999)

• Fastest apparent speeds 6c indicates a jet orientation within 19° of the line of sight ∼ and requires γ 6 ≥ • A monotonic decay of the speed of knots suggests the deceleration of shock fronts Recent Flare-up at HST-1

CORE HST-1 A New Components After Flaring

TeV

GeV

Cheung et al. (2007)

Abramowski et al., ApJ, in press • A flaring from radio through optical to X-ray (factor 50) bands (Harris et al. 2006), ∼ indicating a site for TeV γ-ray emissions (Harris et al. 2009)

• HST-1c evidently splits into two roughly equally bright features: superluminal (c1; 4.3c) and a trailing sub-luminal (c2; 0.47c) features during 2005 - 2006

Q. HST-1 as an origin of superluminal knots (Cheung et al. 2007)? (eg. Biretta et al. 1999) Short Tips for MHD Jets Extraction of Matter and Energy in the Vicinity of the SMBH

Sturrock & Barns (1972) Punsly et al. (2009)

➡ Initiation by Piddington (1970); Sturrock & Barnes (1972) ,inspired by some early work for solar winds (Weber & Davis 1967; Ozernoi & Usov 1973)

• Magnetized accretion disk: Lovelace (1976); Blandford (1976); Blandford & Payne (1983) • SMBH Magnetosphere: Blandford & Znajek (1977); Hirotani et al. (1992); Meier (2001)

• Hybrid model: Meier (1999); Garofalo (2009) Global Picture of MHD Outflows

Two constants along a poloidal stream line: Magnetic tension rBφBp (hoop-stress) drives l = rVφ − 4πρVp both collimation & 1 1 Γ p 1 acceleration e = V 2 + (V Ωr)2 + +Φ Ω2r2 2 p 2 φ Γ 1 ρ 2 Bp + Bφ Vp − − Vp = Vf − (Not a critical point) z-component of the momentum eq.: ρ(V )V = ·∇ z ∂p ρ∂Φ 1 ∂B2 1 Magnetic pressure + (B )B driven −∂z − ∂z − 8π ∂z 4π ·∇ z

The Alfvén Mach number m1/2, the fast magnetosonic number n1/2, the 1/2 poloidal velocity U f, the toroidal velocity g, and the magnetic pitch Bφ/ Bz along a single streamline

Vp = VA

Magneto-centrifugal driven Blandford & Payne (1982)’s solution Pelletier & Pudritz (1992)’s solution Vp = Vs Gas pressure driven

Vφ

Contopoulos (1995) Blandford & Payne (1982) START the Exhaust Inspection of the Jet Engine

Image Credit: W. Steffen Puzzle Remains Unsolved for 2 Decades Distance from the nucleus: z (arcsec) Junor et al. (1999) 10-3 10-2 10-1 1 101 log r (arcsec) -1 0 1 8 N2 L HST-1 D E F AB C Reid et al. (1989) Junor & Biretta (1995) Biretta et al. (1995) 6 Biretta et al. (1999) Cheung et al. (2007) )

c Kovalev et al. (2007) / V

4

Apparent speed ( 2

0

10-2 10-1 1 101 102 103 Distance from the nucleus: z (pc)

• Superluminal motions begin at HST-1, lying about 1” ( 80 pc) from the nucleus ∼ • Many VLBI observations show sub-luminal motions upstream of HST-1

• Visible pc-scale features may reside in slower layers near the surface (Biretta et al. 1999) or possibly standing shocks and/or instability patterns (Kovalev et al. 2007)?

➡ Q. No “systematic” acceleration towards HST-1 exists although collimation occurs asymptotically? Or proper motions do not correspond to the real flow speed at all? Superluminal Motions Upstream of HST-1

Three years monitoring of the M87 jet using European VLBI Network (EVN) at 1.6GHz

Asada, MN, et al. A Missing Link Found!

Distance from the nucleus: z (arcsec) Junor et al. (1999) 10-3 10-2 10-1 1 101 log r (arcsec) -1 0 1 8 N2 L HST-1 D E F AB C Reid et al. (1989) Junor & Biretta (1995) Biretta et al. (1995) 6 Biretta et al. (1999) Cheung et al. (2007) )

c Kovalev et al. (2007) /

V Asada et al. (2011)

4

Apparent speed ( 2

0

10-2 10-1 1 101 102 103 Distance from the nucleus: z (pc) Asada, MN, et al.

✓ Yes, We found final pieces of the puzzle, but γ～1/θ as expected?

• The (bulk) acceleration (γ) and collimation (θ) are correlated in a parabolic streamline α (z r , 1 < α ￿ 2 ) (Zakamska et al. 2008; Komissarov et al. 2009; Tchekhovskoy et al. 2009):γθ ￿ 1 ∝ (α 1)/α • Acceleration/collimation occurs logarithmically (Komissarov 2009):γ z − ∝ ➡ We need to determine the jet structure (α)! The Structure of the M87 Jet

(a) MERLIN image at 1.6 GHz VLBA at 43 GHz VLBA at 15 GHz EVN at 1.6 GHz MERLIN at 1.6 GHz Parabolic streamline Bondi radius (confined by the ISM): 1.73 0.05 z r ± s ∝ Conical streamline (unconfined, freely expanding): (b) EVN image at 1.6 GHz 0.96 0.1 z r ± ∝

jet radius r [r ] [r r radius jet Over-collimation

ISCO

(c) VLBA image at 15 GHz distance from the core z [rs ] ✓ The jet maintains the parabolic stream with α=1.73 over 105 Rs

✓ A transition of streamlines presumably occurs at an ISM transition beyond the gravitational influence of the SMBH

✓ Propose a way to identify the jet ejection radius by tracing back of the ridge line Asada & MN (arXiv:1110.1793) Sub-to Superlumial Transition

Deprojected distance from the nucleus: z (pc) 10-3 10-2 10-1 1 101 102 103 104

N2 L HST-1 D E F ABC Reid et al. (1989), VLBI 1.6 GHz 1 2 10 Biretta et al. (1995), VLA 15 GHz 10 cf. Ejection point (BP82) Biretta et al. (1999), HST Kellermann et al. (2004), VLBA 15 GHz

) Cheung et al. (2007), VLBA 1.6 GHz c / Expected slope on Kovalev et al. (2007), VLBA 15 GHz 1 1 10 α 0.43 0.01 app. the stream line: z∝r θ z− ± (deg.)

V Asada et al. (2011), EVN 1.6 GHz e

( ∝ app. `

10-1 1 Owen et al. (1980, 1989), VLA 15 GHz Junor & Biretta (unpublished), VLBA 609 MHz Reid et al. (1989), VLBI 1.6 GHz

Jet opening angle: Junor et al. (unpublished), VSOP + VLBA 5 GHz

Apparent speed: Junor & Biretta (1995), VLBI 22 GHz -2 -1 10 10 Junor et al. (1999), VLBI 43 GHz Asada et al. (2010), EVN 1.6 GHz Asada et al. (2010), VLBA 15 GHz Ly et al. (2007), VLBA 43 GHz 10-3 10-2 10-2 10-1 1 101 102 103 104 105 10-3 10-2 10-1 1 101 102 103 104 105 Deprojected distance from the nucleus: z (mas) Deprojected distance from the nucleus: z (mas) Asada, MN, et al.

Q. Do they exhibit an asymptotic acceleration from non-relativistic (0.01c) 2-5 to relativistic speed (0.99c) over an extremely large scale 10 Rs ? Magnetic Acceleration & Collimation (MAC) Zone 102 Reid et al. (1989), VLBI 1.6 GHz 1 Biretta et al. (1999), HST γ 101 Kellermann et al. (2004), VLBA 15 GHz ≡ 1 (V/c)2

a Cheung et al. (2007), VLBA 1.6 GHz − Kovalev et al. (2007), VLBA 15GHz Asada et al. (2011), EVN 1.6 GHz ￿ 1 101 Walker et al. (2008), VLBA 43 GHz -1

Acciari et al. (2009), VLBA 43 GHz a (α 1)/α z − ∝ 10-1 Lorentz factor:

1 1 10-2

2/α z 10-1 -3 ∝ ) 10 Reid et al. (1989), VLBI 1.6 GHz c /

Specific Kinetic Energy: Biretta et al. (1999), HST 2GM V

BH ( -2 Kellermann et al. (2004), VLBA 15 GHz Vesc = 10 ` z 10-4 Cheung et al. (2007), VLBA 1.6 GHz ￿ Kovalev et al. (2007), VLBA 15GHz Walker et al. (2008), VLBA 43 GHz 10-3 Speed: Acciari et al. (2009), VLBA 43 GHz -5 10 Asada et al. (2011), EVN 1.6 GHz

10-4 1 101 102 103 104 1 101 102 103 104 Deprojected distance from the nucleus: z (mas) MN, Asada, et al. Deprojected distance from the nucleus: z (mas)

✓ We first identified the jet “MAC” zone in any astrophysical jet system powered by TAW - The jet Lorentz factor follows the expected power-law slope on the specific streamline (relativistic regime)

- The non-relativistic jet seems to be a trans-magnetosonic flow (non-relativistic regime)

✓ The jet specific kinetic energy increases as a conversion from Poynting energy flux - Magnetic flux conservation ( B 5mG at HST-1) gives an estimation of the jet total power at z ～ 1 mas: 43 1 | |∼ Lj 10 erg s− ∼ r B - The system possesses the total current flowing: I 4 1018 φ A ≈ × 0.04 pc 0.8G ￿ ￿￿ ￿ Short Summary (1) • Acceleration and collimation are the fundamental quest for astrophysical jets; none of the system from YSOs to AGNs has exhibited such a simultaneous event in any observations

• Based on the multi-frequency VLBI study of the active galactic nucleus M87, we first present the jet MAC zone of the relativistic outflow.

• We suggest the propagation of TAWs in the jet MAC zone play a role; • Transferring the electromagnetic energy, which is generated in the vicinity of the SMBH,

• Acceleration of the bulk flow due to the conversion of the Poynting to kinetic energy fluxes Outline

✤ Evidence for magnetic acceleration & collimation M87 of the active galactic nuclei (AGN) jet in M87

✤ Quad MHD shock model for sub/super-luminal ejections

✤ Stationary feature in AGN jets constrained by the SMBH

✤ ASIAA “Greenland Telescope Project”: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets B-fields and Helical Structures

M87: VLA C A pair (forward/reverse)? B A I F EF E DW DE

Owen et al. (1989) G (HST-1) Biretta & Meisenheimer (1993)

• Transverse field component is dominant in some knots (HST-1, D, A, and C)

• Sudden changes in B-vector orientation strongly imply the existence of MHD fast/slow-mode waves (w/ high Pol. 20% at inter-knot regions) ∼

• Presence of four shocks , instead of two, is due to the presence of Bφ (equivalent to B⊥ in the simpler planer oblique shocks) Sparks et al. (1996) HST-1 as an Origin of Superluminal Shocks

• HST-1 appears to be the source to produce successive components, each of which splits into forward/reverse bright knots downstream

• By analogy of B-field vector orientations in A & C, quad MHD shocks (“forward” fast/slow and “reverse” slow/fast) may be feasible (e.g., Uchida, Todo, Rosner, & Shibata 1992 for YSOs) z • Special relativistic MHD eqs. in a cylindrical coordinate:

∂Q ∂F + =0, ∂t ∂z γρ 2 2 γ hVφ/c ErBz/(4πc)  2 2 −  r0 Q γ hVz/c + ErBφ/(4πc) , ≡  Bφ   2 2 2 2   γ h p +(E + B + B )/(8π)  Vjet(>VF)  − r φ z    γρVz 2 2 γ hVφVz/c BφBz/(4π)  −  F (Q) γ2hV 2/c2 + p +(E2 + B2 B2)/(8π) . ≡ z r φ − z  cE   r  Cheung et al. (2007)  γ2hV + cE B /(4π)   z r φ    Results for HST-1c1/c2

VFF 0.97 c, VFS 0.94 c, VRS 0.73 c, and VRF 0.67 c Contact discon. (CD) ∼ ∼ ∼ ∼ 10-25

CD (a) ) Reverse slow (RS) Forward slow (FS) -3 RF RS Reverse fast (RF) Forward fast (FF) 10-26 FS

FF (g cm ) -3 al 10-27 VC1, app 4.3c ) -5

∼ -2 10 (g cm -26 (b) VC2, app 0.47c 10
 ∼ -6 Assuming θ 14◦, Slow-mode MHD Shocks 10 ∼ (dyn cm p are not suitable for a DSA VC1 0.97c ∼ 8 10-7 VC2 0.67c -27 (c) 6 ∼ 10 6

4 2.0 4 a 1.5 t (yr) 2 1.0 2 0.5 z (pc) 0 (d) 20 (mG)

10 q B 0 0.2 (e) ) c (

0 q V

-0.2 101 Rest frame of fluid (f)

p 1 ` 10-1

1.2 1.4 1.6 1.8 2 z (pc) MN, Garofalo, & Meier (2010) Related Issues

• An asymmetric structure of inter-shocked regions such as 1 gas compression and pitch angle θ tan− (B /γ/B ) pit. ≡ φ z • The slope δ (=2-2.5) in the particle￿ energy distribution￿ for the diffusive shock acceleration (DSA) (Bell 1978): δ =(r + 2)/(r 1),r ρ /ρ cmp. cmp. − cmp. ≡ post pre

• Particle acceleration is mostly mediated by DSA for quasi-parallel shocks ( θ pit . ￿ 10 ◦ ), but shock drift acceleration (SDA) is main process for larger magnetic obliquity (Sironi & Spitkovsky 2009)

RF FF *FWHM ratio (HST/VLA)～ 0.75 at knot A (Sparks+ 96） δ 2.2 4.3 B 1/r2,B 1/r B /B r z ∝ φ ∝ → φ z ∝ θpit. 3° 17° • Our model can also reproduce another pair of super/sub- luminal components in optical observation (Biretta+ 1999) HST-1￿: 6.00c 0.48c / HST-1 East: 0.84c 0.11c

± ± ) -3 V￿,app 6.0c, 10-25 ∼ RF RS CD VEast,app 0.84c, -26 FS (g cm ∼ 10 FF al Assuming θ 14◦, 10-27 ∼ 1.5 1.6 1.7 1.8 1.9 V 0.99c, ￿ ∼ MN, Garofalo, & Meier V 0.79c East ∼ Outline

✤ Evidence for magnetic acceleration & collimation M87 of the active galactic nuclei (AGN) jet in M87

✤ Quad MHD shock model for sub/super-luminal ejections

✤ Stationary feature in AGN jets constrained by the SMBH

✤ ASIAA “Greenland Telescope Project”: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets It’s a Classical Issue...

VLBA 1.5GHz

An et al. (2010)

Wilkinson et al. (1991), Nature γ-ray Flares, Superluminal Ejections, & Stationary Features in Blazars

• γ-ray flares occur after the ejections of superluminal jet components in EGRET blazars at pc-scale distances from the core (Jorstad et al. 2001) • The γ-ray and the VLBA radio flux at 15 GHz are significantly correlated in Fermi/LAT blazars, suggesting the pc-scale radio core as likely location of flares (Kovalev et al. 2009) • Fermi/LAT γ-ray blazars are more likely to have larger Doppler boosting factors (Savolainen et al. 2010) • Fermi/LAT γ-ray blazars have larger apparent opening angles (Pushkarev et al. 2009) • “Quasi”-stationary patterns in VLBI surveys (Jorstad et al. 2001, 2005; Kellermann et al. 2004); • 27 sources among 42 EGRET γ-ray bright blazars indicate rather stationary hot spots than very slow flow patterns • A significant global maximum in the range of projected distances shorter than 0.5 mas for 30 % of the sources in the sample Jorstad et al. (2001) BL Lac: 1803+784

Britzen et al. (2010) Jorstad et al. (2005) Mahmud et al. (2009) FSRQ: 2251+158 (3C 454.3)

Jorstad et al. (2001) Jorstad et al. (2005) BL Lac: 0851+202 (OJ287)

Jorstad et al. (2005) BL Lac: 0851+202 (OJ287)

The Astrophysical Journal Letters,726:L13(6pp),2011January1 doi:10.1088/2041-8205/726/1/L13 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. !

LOCATION OF γ -RAY FLARE EMISSION IN THE JET OF THE BL LACERTAE OBJECT OJ287 MORE THAN 14 pc FROM THE CENTRAL ENGINE

Ivan´ Agudo1,SvetlanaG.Jorstad1,2,AlanP.Marscher1,ValeriM.Larionov2,3,JoseL.G´ omez´ 4, Anne Lahteenm¨ aki¨ 5,MarkGurwell6,PaulS.Smith7,HelmutWiesemeyer8,ClemensThum9,JochenHeidt10, Dmitriy A. Blinov2,3,FrancescaD.D’Arcangelo1,11,VladimirA.Hagen-Thorn2,3,DariaA.Morozova2, Elina Nieppola5,12,MarRoca-Sogorb4,GaryD.Schmidt13,BrianTaylor1,14,MerjaTornikoski5,andIvanS.Troitsky2 1 Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, USA; [email protected] 2 Astronomical Institute, St. Petersburg State University, Universitetskij Pr. 28, Petrodvorets, 198504 St. Petersburg, Russia 3 Isaac Newton Institute of Chile, St. Petersburg Branch, St. Petersburg, Russia 4 Instituto de Astrof´ısica de Andaluc´ıa, CSIC, Apartado 3004, 18080, Granada, Spain 5 Aalto University Metsahovi¨ Radio Observatory, Metsahovintie¨ 114, FIN-02540 Kylmal¨ a,¨ Finland 6 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 7 Steward Observatory, University of Arizona, Tucson, AZ 85721-0065, USA 8 Instituto de Radio Astronom´ıa Milimetrica,´ Avenida Divina Pastora, 7, Local 20, E-18012 Granada, Spain 9 Institut de Radio Astronomie Millimetrique,´ 300 Rue de la Piscine, 38406 St. Martin d’Heres,` France 10 ZAH, Landessternwarte Heidelberg, Konigstuhl,¨ 69117 Heidelberg, Germany 11 MIT Lincoln Laboratory, 244 Wood Street, Lexington, MA 02421, USA 12 Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Vais¨ al¨ antie¨ 20, FI-21500 Piikkio,¨ Finland 13 National Science Foundation, 4201 Wilson Boulevard, Arlington, VA 22230, USA 14 Lowell Observatory, Flagstaff, AZ 86001, USA Received 2010 September 20; accepted 2010 November 29; published 2010 December 14

ABSTRACT We combine time-dependent multi-waveband flux and linear polarization observations with submilliarcsecond-scale polarimetric images at λ 7mmoftheBLLacertaetypeblazarOJ287tolocatetheγ -ray emission in prominent flares in the jet of the source= > 14 pc from the central engine. We demonstrate a highly significant correlation between the strongest γ -ray and millimeter-wave flares through Monte Carlo simulations. The two reported γ -ray peaks occurred near the beginning of two major millimeter-wave outbursts, each of which is associated with a linear polarization maximum at millimeter wavelengths. Our very long baseline array observations indicate that the two millimeter-wave flares originated in the second of two features in the jet that are separated by > 14 pc. The simultaneity of the peak of the higher-amplitude γ -ray flare and the maximum in polarization of the second jet feature implies that the γ -ray and millimeter-wave flares are cospatial and occur > 14 pc from the central engine. We also associate two optical flares, accompanied by sharp polarization peaks, with the two γ -ray events. The multi-waveband behavior is most easily explained if the γ -rays arise from synchrotron self-Compton scattering of optical photons from the flares. We propose that flares are triggered by interaction of moving plasma blobs with a standing shock. The γ -ray and optical emission is quenched by inverse Compton losses as synchrotron photons from the newly shocked plasma cross the emission region. The millimeter-wave polarization is high at the onset of aflare,butdecreasesastheelectronsemittingatthesewavelengthspenetratelesspolarizedregions. Key words: BL Lacertae objects: individual (OJ287) – galaxies: active – galaxies: jets – gamma rays: general – polarization – radio continuum: galaxies

1. INTRODUCTION providing well-sampled light curves of blazars that allow de- tailed studies of the timing of γ -ray flares relative to those at The information that γ -ray observations can provide on the other spectral ranges (e.g., Abdo et al. 2010d;Jorstadetal.2010; physical properties of active galactic nuclei in general, and Marscher et al. 2010). blazars in particular, depends on where such γ -ray emission The technique developed by Marscher et al. (2010) originates, which is still under debate (e.g., Marscher & Jorstad and Jorstad et al. (2010)usesultra-highangular-resolution 2010). Variability studies of γ -ray and lower-frequency emis- ( 0.15 mas) monitoring with very long baseline interferom- sion from blazars provide important insights into this problem etry∼ (VLBI) to resolve the innermost jet regions and monitor by relating timescales of variability with physical sizes in the changesQ. Just in jet structure. two Observations shocks with roughly are monthly needed source. However, although γ -ray variability in blazars can occur observations, supplemented by more concentrated campaigns, on very short timescales (of a few hours, e.g., Mattox et al. 1997; provide time sequences of total and polarized intensity images Foschini et al. 2010), this does not necessarily imply that high- of(i.e., the parsec-scale quad jet that canMHD be related toshock)...? variations of the flux energy flares take place at short distances ( 1pc)fromthecen- and polarization at higher frequencies. tral engine (see Marscher & Jorstad 2010)." In fact, Lahteenm¨ aki¨ In this Letter, we employ this technique to investigate the &Valtaoja(2003)andJorstadetal.(2001a, 2001b)provided location of the flaring γ -ray emission in the BL Lacertae (BL evidence that γ -ray outbursts may arise in the millimeter-wave Lac) object OJ287 (z 0.306), a well studied and highly = emitting regions !1pcdownstreamofthecentralengine.The variable blazar at all available spectral ranges (e.g., Abdo et al. Large Area Telescope (LAT) on board the Fermi Gamma- 2010a, 2010c). Throughout this Letter, we adopt the standard 1 1 ray Space Telescope has sufficient sensitivity to test this by ΛCDM cosmology with H0 71 km s Mpc , ΩM 0.27, = − − =

1 Variability and stability in blazar jets 2105

Table 3. Properties of the OJ 287 host galaxy from different publications.

Band mMre (kpc) Morph. dc? log MBH

Hutchings et al. (1984) R – > 23.1 – – ? <9.0 − Yanny et al. (1997) F814W 18.30 1.30 23.05 – – 0.4 arcsec 8.9 ± − Wright et al. (1998) K 12.0 29.15 6.68 Disc ? – − Wright et al. (1998) K 12.2 29.14 11.13 None preferred ? 10.4 − Heidt et al. (1999) R 18.41 22.96 4.4 Bulge Yes 8.9 − Heidt et al. (1999) R 19.32 22.00 10.2 Disc Yes – − Urry et al. (2000) F702W >18.53 > 23.01 – – ? <8.9 − Pursimo et al. (2002) R 18.91 22.79 4.5 Bulge ? 8.8 − Nilsson et al. (2003) R >18.1 > 23.27 – – Yes <9.0 − O’Dowd & Urry (2005) F28x50LP >18.53 > 23.02 – – ? <8.9 − Note. Columns have following meanings. The first column shows theBL publication Lac: used. Band: 0851+202 filter used; m: apparent (OJ287) host magnitude; M: absolute host magnitude; re (kpc): effective radius of galaxy in kpc; morph.: morphology, if not specified, none given in the publication; dc?: decentring of host• withDouble-peaked respect to point bursts source (yes,at regular no, ? ifintervals not mentioned, of 12 values yr during given inthe last 40 yr ∼ ∼ arcseconds); log MBH: log of the mass of the central➡ blackSee hole, Villforth in solar masses.et al. (2010) for discussions about BBHs (none of the models is able to explain all observations) limits to estimate the upper limit for the mass of the central black year 1900 1920 1940 1960 1980 2000 hole. 60 We use relations published in Novak et al. (2006) to estimate the mass of the central black hole. For the R-band data, we use the 50 relation based on data from Bettoni et al. (2003). We use the same relation for filters F814W, F702W and F28x50LP as the differences 40 between these bands are minimal and no colour corrections for these

filters are available. For the K-band data, we use colour corrections 30 from Poggianti (1997) to transform the magnitude to the J band; we use the relation based on data from Marconi & Hunt (2003) to flux / mJy V-band 20 derive the black hole mass. Estimating the central black hole mass from the optical data gives 10 values of log MBH ! 9. The results from the only available NIR measurement gives a value of log MBH 10. The big difference is ≈ 0 caused by the fact that combining the optical and NIR results gives 2410000 2415000 2420000 2425000 2430000 2435000 2440000 2445000 2450000 2455000 a colour that strongly deviates from the colours of normal elliptical JD or disc galaxies at similar redshift. Note that relations as presented Figure 24. OJ 287 V-band flux from 1885 to 2009. R-band fluxes were in Novak et al. (2006) only hold for galaxies with normal SEDs. If converted to V-band fluxes using V R 0.4 mag. the galaxy strongly deviates from a normal SED, black hole masses − = Villforth et al. (2010) derived using luminosities are no longer reliable. However, upper sparse to determine the exact time of the outbursts accurately; this limits for optical host galaxy luminosities and black hole masses effects the calculations for the models. Therefore, we believe that derived from optical data hold. neither are exact timing predictions possible nor is it possible to After discussing the properties of OJ 287 not related to the light derive exact outburst times from the light curve. Due to this fact, curve, we will continue by putting together a list of prominent we will not give much importance to high timing accuracy in this properties of the light curve and finish by presenting a clear list of discussion. However, we do discuss if models strongly deviate from requirements which we use to rate the different models. A plot of the measured time of the outburst. the entire flux monitoring data, from 1885 to 2009, is presented in ‘Pseudo-periodicity’, this rather awkward word describing the Fig. 24. light curve of OJ 287, was introduced to emphasize that the out- Exact timing has received a lot of attention, especially in the bursts in OJ 287 appear regularly while deviating from periodicity. Lehto & Valtonen model and its successors. However, in order to In particular the 2005 burst strongly deviates from periodicity, being be able to calculate results from their models, all authors had to observed about a year earlier than expected for strict periodicity. It is make simplifications. Including all possible influences (i.e. MHD true that strong, rather regularly appearing outbursts have been ob- and general relativistic effects, warped disc etc.) would yield mod- served from the 1970s till the present. However, this represents only els with too many adjustable parameters. Additionally, solving the four cycles. We do not believe that earlier outbursts can clearly be problem of a binary black hole together with an accretion flow established as the sampling was too sparse (see Fig. 24), especially would require fully relativistic MHD simulations that also calcu- as there are about 10 yr long gaps in the data. The fact that outbursts late the radiation transfer; this is not possible with current MHD were observed around the time expected before 1970 does not prove models and computer power. Therefore, we do not believe that it is that there were periodic outbursts – not even pseudo-periodic out- possible to calculate the timing of the bursts with an accuracy in the bursts for that matter. For certainty, one can only say that the data order of days. Additionally, the light curve has ‘holes’ caused by before the 1970s do not contradict regularly appearing outbursts at OJ 287 being to close to the Sun to be observed. As we discussed 12 yr intervals. Additionally, OJ 287 may be ‘losing’ its regularly in Section 3.1, this can have the effect that the exact time of the appearing∼ outbursts. The peak fluxes in the double-peaked outbursts outburst can only be determined with an accuracy in the order of have been declining significantly since the first well-sampled burst weeks to months. Also, before around 1970 the sampling was too in the 1970s (see Fig. 24). Between the 1994–1995 burst and the ∼

C C $ 2010 The Authors. Journal compilation $ 2010 RAS, MNRAS 402, 2087–2111 Short Summary (2)

• AGN Jets scaled by SMBH(M●)

• Jet MAC nozzle powered by TAW

• Transition of streamlines by forming a stationary knot (SK)

• VHE γ-ray emissions & ejection of superluminal knots

• M87: a kind of “Rosetta stone” for AGN astrophysics

Paraboloidal structure: Re-collimation & accumulating Conical structure: z rα, 1 <α 2 azimuthal B-field z r (γθ 1) ∝ ≤ ∝ ∼ β p z− pism 0 ism ∝ ∇ ∼ Jet Magnetic Acceleration & Collimation (MAC) Zone TAW I SMBH Bφ SK

MN & Norman Outline

✤ Evidence for magnetic acceleration & collimation M87 of the active galactic nuclei (AGN) jet in M87

✤ Quad MHD shock model for sub/super-luminal ejections

✤ Stationary feature in AGN jets constrained by the SMBH

✤ ASIAA “Greenland Telescope (GLT)” Project: sub-mm VLBI for exploring the SMBH shadow & origin of AGN jets Towards the Origin

Q. Can we expect the streamline to be VLBA at 43 GHz extrapolated continuously towards the VLBA at 15 GHz EVN at 1.6 GHz jet launching point? MERLIN at 1.6 GHz Parabolic streamline Bondi radius (confined by the ISM): 1.73 0.05 Hmmm, it may not be ... z r ± ∝ s • The jet may transit into sub-Alfvénic Conical streamline (unconfined, freely regime; poloidal fields play a role in expanding): 0.96 0.1 the radial force equilibrium z r ± 43 GHz “core” ∝

jet radius r [r ] [r r radius jet (Hada et al. 2011) • Classical picture of the VLBI core emission as a base of conical jet (Blandford & Königl 1979) is unlikely ISCO Over 4 orders! ➡ a modification of “core-shift” (a jet would start at the stagnation surface, outside the ergoshere) distance from the core z [rs ] Asada & MN (arXiv:1110.1793) • Existing GRMHD simulation results may not fit to the observation feature

• Driving mechanisms for jets; from accretion disk and/or the spinning SMBH? GLT Project (2009-)

• International partnership: ASIAA, CfA, MIT Haystack, NRAO • Facility: Summit station (NSF-supported research territory) • Altitude: 3,200 m • Accessibility: C-130 aircraft (summer) / Twin otter aircraft or traverse (winter) • NA ALMA prototype 12 m antenna (now at Socorro, NM to retrofit for operation in GL) • First light in 2015-

Prototype Antenna Greenland deployment.

• Measurements (Tipping: every 10 min. and Zenith: every 1 sec. for temp. )at 225GHz have started from 08/17/2011 • Temperature is getting lower and opacity is getting stable ...

2011 VLBI P. Martin-Cocher 16 Workshop, Taipei Sub-mm VLBI: Imaging the SMBH in VirA*

Jet Model: a=0.99, Submm VLBI Eureka rftp=1M, vz～0.05c, vφ～0.5c N 80.0, W 85.9, altitude: 610 m

4"#*5%! 6"))'+$7%)8!

Summit Camp N 72.5, W 38.5, altitude: 3200 m Ideal image: 340 GHz

!"#$#%&'()*+*#$,(#$-'+*$+*-./0$ 693!

3:93! Ideal image: 340 GHz w/ GL

$1*-+*&$%+$233! 37 APEX, Hawaii(SMA),IAA LMT Advisory, Pico PanelVeleta Meeting, SMTO 03.21.2011, and a potential Greenland Site.

Greenland Site will improve the UV-coverage a lot for Black Hole Candidate M87. The Shadow silhouette in M87 could be resolved in sub-millimeter band. The “Face-On” orientation preferred to M87 makes its Shadow easy to detect, but causes difficulty in Black Hole Spin Measurement. Single Dish Usages: THz Astronomy

• Time-variable FIR - sub-mm Universe Monitoring of AGNs M. Nakamura, K. Asada (1) Young radio galaxy (2) Blasars Submm/FIR can avoid f-f/ THz is just above the SSA synchrotron self-absorption peak ! better determination sensitivity ~ 100 mJy of magnetic field. sensitivity ~ 100 mJy

From UMRAO data base

Time vs Lobe Size

Born in 1959 !!

Asada et al. (2006) Abdo et al. (2010)