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

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)

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

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

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

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

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

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

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

Thermal (black) Non-thermal (blue) Optically thick Optically thin Results: Synchrotron spectrum Thermal Hot spot

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

3C295 lobe z=0.46 size=20kpc B=4 x10 -4 G Sign of thermal emission ? Thermal component Non-thermal component 74MHz data:Taylor & Perley(1992)

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

Log ν [Hz] Disk black body Cyc-syn emission - Size : ~ 300 R s - Brightness temperature: Te~T b ~10 9 K for ν < 20GHz - Targets : Nearby Seyferts * ~ 20GHz Log νL ν [erg/s] SKA   Kawaguchi +01 Imaging Accretion Disk-Corona Higher freq. is essential to resolve it. ⇒ ALMA Accretion disk BH Corona PI:Kawaguchi

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

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

AGNs in Blue Compact Dwarfs? II ZW 40 VLA(3-4’’) SMA (5’’) Hirashita 2011 AGN (RIAF) Starburst (Free-free) ν -0.1 SKA 0.6 VLA(0.1”) Beck+02 Spectral index is the key to distinguish them. ⇒ frequency (1-15 GHz) ALMA ν 1/3 - BCD: ongoing SF, metal poor - No evidence of bright AGNs (optical and X-ray) How about Faint AGNs ? Starburst (Free-free) PI:Kawakatu L RIAF,max =2x10 38 erg/s M BH =800M sun

1.AGN outflow - Relativistic thermal emission Thermal : 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 Summary If you are interested in above topics, please join us.

Thanks for your attention! 감사 합니다

Back-up slides

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

Thermal + 2-step acceleration γ max γ nth Fermi acceleration Fermi acceleration γ -2.5 Thermal γ br Injection region γ 0 Lorentz factor γ N(γ) Absorption of electromagnetic waves emitted at the harmonic of cyclotron frequency of cold plasma

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

Bulk Lorentz factor Γ j =O(10) → Thermal Electron temperature (θ e )-dependence

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

Magnetic field(B)-dependence Larger B hs ⇒ peak frequency is higher.

3C295 lobe z=0.464 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 Viewing angle ： 63° Consistent with type 2 AGN Thermal+2-Step Acceleration Model

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

3C295 lobe z=0.464 Thermal+2-Step Acceleration Model 74MHz

Pure non-thermal cases

FRII range

Ukrainian T-shaped Radio telescope, second modification (UTR-2) Resolution: 40’x 40’ Frequency: 10-30MHz Collective area: 150,000 m 3

E max E min Non-thermal E -s Non-thermal E -sthermal emission e+e+ e-e- e+e+ e-e- p e-e- Thermal electron or thermal/non-thermal proton are needed!  Missing Power problem Electron energy Can we observe thermal emission from cocoon/hot spots? Total pressure of cocoon e.g., Ito+08

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

Fate of expanding radio bubbles Its fate is governed by i.e., Supersonic or Sub-sonic? SKA can fill the gap mini-lobes and large FR I and IIs. Kawakatu, Nagai, Kino, 2008 ρ ext A h v h 2 =const deceleration acceleration

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

O’Dea Interesting GPS sources

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

SED of young BCDs II ZW 40 (age ~ 3Myr) VLA(3-4’’) SMA (5’’) Hirashita 2011 Free-Free AGN L RIAF,max =2x10 38 erg/s M BH =800M sun, α=0.1 ν 1/3 SB (Free-free) ν -0.1 VLA(0.1’’) ALMA 0.6 SKA dust

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

Low luminosity AGN SED : SgrA* ν 4/3 Peak frequency ： Peak luminosity ： Mahadevan 97

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

Japanese VLBI Network (JVN) Noise level: ~ 0.2mJy (10 stations, 4hrs) Spatial resolution: 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?

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