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AGN inflow/outflow with SKA

Cygnus A at 240 MHz with LOFAR. AGN inflow/outflow with SKA. (C) J. McKean. Nozomu Kawakatu ( University of Tsukuba ) On behalf of SKA-Japan AGN sub-WG. Workshop on East-Asia collaboration for SKA@KASI, Nov.30-Dec. 2 2011. Members. N. Kawakatu (Univ. of Tsukuba) M. Kino (NAOJ)

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AGN inflow/outflow with SKA

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  1. Cygnus A at 240 MHz with LOFAR AGN inflow/outflow with SKA (C) J. McKean Nozomu Kawakatu (University of Tsukuba) On behalf of SKA-Japan AGN sub-WG Workshop on East-Asia collaboration for SKA@KASI, Nov.30-Dec. 2 2011

  2. Members N. Kawakatu (Univ. of Tsukuba) M. Kino (NAOJ) T. Kawaguchi (Univ. of Tsukuba) A. Doi (ISAS/JAXA) S. Kameno (Kagoshima Univ.) T. Hayashi (Univ. of Tokyo) H. Ito (Yukawa Institute for Theoretical Physics) M. Imanishi (NAOJ/Subaru) H. Nagai (NAOJ) M.Umemura (Univ. of Tsukuba)

  3. Outline 1. Why AGN with SKA ? 2. AGN outflow 3. AGN inflow 4. Summary

  4. Why AGN with SKA? Because it will have VLBI-order resolution (D~3000km) with sub-μ Jy revel sensitivity! Wilkinson 2004

  5. Key points for AGN science with SKA 1. Wide-band spectra 2. Searching for very faint radio emission 3. Synergy with ALMA + other telescope

  6. AGN outflow • ・Emission from AGN jets remnants • Relativistic thermal emission • (NK & Kino, in preparation) • Non-thermal emission (Ito’s talk) • ・Young RGs and BAL QSOs (Hayashi’s talk) • Kino, Ito, Hayashi, Nagai,Kawakatu

  7. AGN jets remnants AGN jets ⇒ Collisionless shock Hot spots: reverse shock Shell :forward shock AGN jets remnants is good laboratory to reveal the physics of a collisionless shock.

  8. Electron number distribution Hybrid populations: Relativistic Maxwellian + Power law Power-law index γ: Lorentz factor δ：Non-thermal energy /Total energy

  9. Plasma temperature Bulk Lorentz factor kinetic energy of AGN Jets ⇒Thermal energy＠hot spots Assumption: 2-Temperature plasma 5.2 9.2 “Shock jump conditons” e.g., Blandford & McKee 1976, Kino & Takahara 2004 Kino& Takahara 04

  10. Results: Synchrotron spectrum Optically thick Optically thin Hot spot Thermal bump @10-100MHz Non-thermal (blue) Thermal (black)

  11. Exploring thermal synchrotron with LOFAR/SKA CygnusA 3C295 ◆ Frequency：＜500MHz ⇒LOFAR(10-250MHz), SKA(Low-band) ◆ Spatial resolution： Spatial resolution LOFAR ～2 arcsec @250MHz SKA ～0.1 arecsec @250MHz Typical hot spots size Cygnus A (z=0.057) 2-3 arecsec 3C295 (z=0.46) 0.1-0.2 arcsec

  12. Sign of thermal emission ? VLA@74MHz Non-thermal component 2 Thermal component 3C295 lobe z=0.46 size=20kpc B=4 x10-4 G 0 6 7 8 9 10 data:Taylor & Perley(1992)

  13. AGN inflow • Imaging Accretion Disk-Corona • Searching for AGNs in ULIRGs/BCDs • Kawaguchi, Imanishi, Kawakatu, • Umemura, Doi, Kameno, Hirashita

  14. Accretion disk BH Corona PI:Kawaguchi 4645444342 41 40 39 38 Kawaguchi +01 n-1 Imaging Accretion Disk-Corona Diskblack body Log νLν [erg/s] Cyc-synemission n* ~20GHz n -1 • Size : ~ 300 Rs • Brightness temperature: • Te~Tb ~109K for ν < 20GHz • - Targets : Nearby Seyferts ALMA SKA 9 10 11 12 13 14 15 16 17 18 19 Higher freq. is essential to resolve it. ⇒ SKA@high-band Log ν [Hz]

  15. AGN or Starburst in ULIRGs? PI:Imanishi Which is the energy source of ULIRGs ? Extremely powerful energy sources behind dust @z <0.1 IR-spectroscopy study (Imanishi+06,07,08,09) ★ ? AGN SB AGN: compact Starburst: extended High surface brightness radio core emission = AGN Observations with high spatial resolution at >5 GHz avoiding FFA & SSA are required. ⇒ SKA@high-band

  16. Japanese VLBI Network (JVN) Noise level: ~ 0.2mJy (10 stations, 4hrs) Spatial resolution: ~3mas@8GHz Radio bright ULIRGs ( > 5mJy) It would be possible to distinguish between AGNs and starbursts. Radio faint ULIRGs (< 5mJy) Collaboration with KVN +CVN?

  17. AGNs in Blue Compact Dwarfs? PI:Kawakatu - BCD: ongoing SF, metal poor - No evidence of bright AGNs (optical and X-ray) How about Faint AGNs ? Hirashita 2011 II ZW 40 SMA (5’’) VLA(3-4’’) Starburst (Free-free) ν1/3 AGN (RIAF) LRIAF,max=2x1038 erg/s MBH=800Msun SKA ALMA Starburst (Free-free) ν-0.1 0.6 VLA(0.1”)Beck+02 Spectral index is the key to distinguish them. ⇒ SKA@mid-band frequency (1-15 GHz)

  18. Summary • AGN outflow • - Relativistic thermal emission • Thermal bump @10-100MHz : LOFAR/SKA • → Electron temperature & electron acceleration efficiency • “Revealing physics of a collisionless shock” • Non-thermal emission from AGN shells (Ito’s talk) • Young RGs and BAL QSOs (Hayashi’s talk) • 2.AGN inflow • Imaging nearby Accretion Disk-Corona • - Searching for faint AGNs in ULIRGs /BCDs If you are interested in above topics , please join us.

  19. Thanks for your attention! 감사 합니다

  20. Back-up slides

  21. How about thermal + Non-thermal emission model ? 3C295 lobe z=0.464 This model cannot reproduce the observational data…

  22. Thermal + 2-step acceleration Thermal Injection region γ0 N(γ) Fermi acceleration γ-2.5 γnth γbr γmax Lorentz factor γ Absorption of electromagnetic waves emitted at the harmonic of cyclotron frequency of cold plasma

  23. Min. of the electron number density Stationary hot spot. i.e., Injection by jet=sideways escape min. neby NT. electrons in the hotspot Relativistic Shock Junction (Blandford & McKee 1976)

  24. Electron temperature (θe)-dependence Bulk Lorentz factor Γj=O(10) → Thermal bump@10-100MHz

  25. Electron acceleration efficiency （δ）-dependence (Ito+08) Non-T(black) Amplitude of thermal bump → Electron acceleration efficiency

  26. Magnetic field(B)-dependence Larger Bhs ⇒ peak frequencyis higher.

  27. Thermal+2-Step Acceleration Model 3C295 lobe z=0.464 Viewing angle：63° Consistent with type 2 AGN Projected size 注）熱的バンプ 磁場、熱的電子数、温度大→斜め右上方向にシフト ローブのサイズ大→ほぼ真上にシフト

  28. Prediction: Radio spectra from hot spot in 3C295 LOFAR, SKA? Taylor & Perley(1992)

  29. Thermal+2-Step Acceleration Model 3C295 lobe z=0.464 VLA@74MHz

  30. Pure non-thermal cases

  31. FRII range FRII range

  32. Ukrainian T-shaped Radio telescope, second modification (UTR-2) Resolution: 40’x 40’ Frequency: 10-30MHz Collective area: 150,000 m3

  33. thermal Non-thermalE-s Emin Emax Missing Power problem N(E) e- e- emission e+ e+ e- p Electron energy Total pressureof cocoon Thermal electron or thermal/non-thermal proton are needed! e.g., Ito+08 Can we observe thermal emission from cocoon/hot spots?

  34.  Emissions from Shells Associated with Dying Radio galaxies In general, AGN shell is dim, but… D=1Gpc Ito’s talk Physics of forward shock :electron acceleration efficiency SKA@mid & high band + ALMA

  35. Fate of expanding radio bubbles Kawakatu, Nagai, Kino, 2008 acceleration deceleration ρext Ah vh2=const Its fate is governed by v_h @~kpc. i.e., Supersonic or Sub-sonic? SKA can fill the gap mini-lobes and large FR I and IIs.

  36. Other Candidates ? R=22 kpc R=200pc R=2.2 kpc

  37. Interesting GPSsources O’Dea +1990

  38. Multiple IMBHs in BCD? Bondiaccretion Hirashita & Hunt +06, Hirashita & Sakamoto +10 IMBHs BCD (~100pc) You may detect RIAF emission from multiple IMBHs. Spatial resolution：0.01” :1pc@10Mpc , 0.1”: 10pc@10Mpc

  39. SED of young BCDs Hirashita 2011 II ZW 40 (age ~ 3Myr) SMA (5’’) VLA(3-4’’) dust Free-Free AGN ν1/3 LRIAF,max=2x1038 erg/s MBH=800Msun, α=0.1 VLA(0.1’’) ALMA SKA 0.6 SB (Free-free) ν-0.1

  40. Maximum Luminosity of RIAF 制動放射∝密度の２乗 e.g., Balbus & Hawley 1991: Machida et al. 2000 Log(Mass accretion rate) No solution of RIAF Log(surface density)

  41. Low luminosity AGN SED : SgrA* ν4/3 Peak frequency： Peak luminosity ： Mahadevan 97

  42. ～60 kpc What are AGNs? Compact (~ 100 AU) and luminous (~ 1046-47 erg/s) objects cf. typical galaxies 1044erg/s @ kpc SMBH ~108-9M Relativistic Jet v ~ c Accretion disk AGN jets: Biggest (～100kpc) and powerful relativistic plasma fountain in the universe.

  43. Japanese VLBI Network (JVN) Noise level: ~ 0.2mJy (10 stations, 4hrs) Spatial resolution: ~3mas@8GHz Radio bright ULIRGs ( > 5mJy) It would be possible to distinguish between AGNs and starbursts. If these are not enough (FFA,SSA), we may need observations at 22GHz. Collaboration with KVN +CVN?

  44. 2500 km 5000 km

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