agn science with ska motoki kino (naoj) on behalf of ska-japan agn sub-wg japan-ska workshop (nov. 5...
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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 Slide 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.) Slide 3 Outline 1.Why AGN with SKA? 2.AGN outflow 3.AGN inflow 4.Summary Slide 4 Because it will have VLBI-order resolution (D~3000km) with sub- Jy revel sensitivity! Wilkinson 2004 Why AGN with SKA? Slide 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 Slide 6 AGN outflow - kpc jets - Cocoons - Radio-quit AGNs Kino, Nagai, Ito, Kawakatu Slide 7 Internal Structure in [email protected]? Odea+98 3C380, VLA 15GHz Koyama, MK+ in prep In general, it is not easy to see knots by current VLBIs sensitivity. core K1 730 mas VLBA+Y1, 1.4GHz B amplified!? Beyond 1-zone: K1 = compact + diffuse region? [email protected]/high-band => Particle acceleration 2kpc 1 arcsec=6.9 kpc Slide 8 Very few reports on jet motions at ~kpc. [email protected] => Relativistic Hydrodynamics 10 pc 150 kpc Krichbaum+ [email protected]? VLBIs see only here. Cygnus A It is very difficult to detect motions at kpc jets by VLBIs/VLA. Slide 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 ext A h v h 2 =const deceleration acceleration Slide 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+ [email protected] Low-energy-electrons tell us the true shape of jet-remnants (not lobes but a cocoon) because of its longer cooling time. [email protected] LOFAR @240MHz (C) J. McKean Slide 11 Radio-quiet is really radio-quiet? Observations of radio-quiet populations have been started (ex. Narrow Line Seyfert 1 galaxies) Doi+ 2007 SKAs sensitivity will allow us to detect weak radio emission from currently radio-quiet AGNs. =>Hint for underdeveloped jets? By Japanese VLBI [email protected] Slide 12 AGN inflow -Imaging Accretion Disk-Corona -Quest for AGNs in ULIRGs/BCDs Kawakatu, Kawaguchi, Imanishi, Umemura, Doi, Kameno, Hirashita Slide 13 9 10 11 12 13 14 15 16 17 18 19 46 45 44 43 42 41 40 39 38 Log [Hz] bremsstrahlung Disk black body Cyc-syn emission - Size : ~ 300 R s - Brightness temperature: T b ~10 9 K for < 20GHz - Targets : Nearby Seyferts * ~ 20GHz Log L [erg/s] SKA Kawaguchi +01 Imaging Accretion Disk-Corona Higher freq. is preferable to resolve it. [email protected] Slide 14 AGN or Star-Burst in ULIRGs? Which is the energy source of ULIRGs ? Luminous energy sources behind dust @z