1. AGN Science with SKA Motoki Kino (NAOJ) On behalf of SKA-Japan AGN sub-WG Japan-SKA workshop (Nov. 5 th 2010, NAOJ) (C) J. McKean Cygnus A at 240 MHz with LOFAR

2. Members N. Kawakatu (Tsukuba Univ., Representative) M. Kino (NAOJ, Jr. Representative) T. Kawaguchi (Tsukuba Univ.) H. Nagai (ISAS/JAXA) H. Ito (Tohoku Univ.) S. Kameno (Kagoshima Univ.) A. Doi (ISAS/JAXA) M. Imanishi (NAOJ/Subaru) M.Umemura (Tsukuba Univ.)

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

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

5. Points can be summarized into the following two concepts: 1. Filling the gap between VLBIs and VLA 2. Quest for very faint radio emission

6. AGN outflow - kpc jets - Cocoons - Radio-quit AGNs Kino, Nagai, Ito, Kawakatu

7. Internal Structure in shocks@kpc? O’dea+98 3C380, VLA 15GHz Koyama, MK+ in prep In general, it is not easy to see knots by current VLBI’s sensitivity. core K1 730 mas VLBA+Y1, 1.4GHz B amplified!? Beyond 1-zone: K1 = compact + diffuse region? ⇒ SKA@mid/high-band => Particle acceleration 2kpc 1 arcsec=6.9 kpc

8. Very few reports on jet motions at ~kpc. ⇒ SKA@high-band => Relativistic Hydrodynamics 10 pc 150 kpc Krichbaum+ Motion@kpc? VLBIs see only here. Cygnus A It is very difficult to detect motions at kpc jets by VLBIs/VLA.

9. Fate of expanding radio bubbles 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. Kawakatu, Nagai, Kino, 2008 ρ ext A h v h 2 =const deceleration acceleration

10. Yaji+ 2010 Low Energy Electrons SKA-low band will show us a new world of radio cocoon. => True total power of jets (MK+05, Ito+08) Chandra+ VLA@330MHz Low-energy-electrons tell us the true shape of jet-remnants (not lobes but a cocoon) because of its longer cooling time. VLA@5GHz LOFAR @240MHz (C) J. McKean

11. “Radio-quiet” is really radio-quiet? Observations of “radio-quiet” populations have been started (ex. Narrow Line Seyfert 1 galaxies) Doi+ 2007 SKA’s sensitivity will allow us to detect weak radio emission from currently “radio-quiet” AGNs. =>Hint for underdeveloped jets? By Japanese VLBI Network@8GHz

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

13. 9 10 11 12 13 14 15 16 17 18 19 46 45 44 43 42 41 40 39 38 Log ν [Hz] bremsstrahlung Disk black body Cyc-syn emission - Size : ~ 300 R s - Brightness temperature: 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 preferable to resolve it. ⇒ SKA@high-band

14. AGN or Star-Burst in ULIRGs? Which is the energy source of ULIRGs ? Luminous energy sources behind dust @z <0.1 AGN: compact Star-Burst: extended ★ AGN SB High surface brightness radio core emission = AGN IR-spectroscopy study (Imanishi+06,07,08,09) ? Observations with high spatial resolution avoiding free-free absorption are required. ⇒ SKA@high-band

15. AGNs in Blue Compact Dwarfs? II ZW 40 (age ~ 3Myr) VLA(3-4’’) SMA (5’’) Hirashita & Sakamoto (in preparation) Free-Free AGN (RIAF) ν 1/3 Star burst (Free-free) ν -0.1 SKA 0.6 VLA(0.1”): Beck+02 metal poor Spectral index is the key to distinguish them. ⇒ SKA@mid-band frequency (1-15 GHz)

16. 1.AGN outflow - kpc scale jets - Radio Bubbles: Super-sonic or sub-sonic? - Cocoons - “Radio-quiet” AGNs 2. AGN inflow - Imaging nearby Accretion Disk-Corona - Quest for AGNs at the core of ULIRGs - Quest for AGNs at the core of BCDs Summary