1. Particles and Fields in Lobes of Radio Galaxies Naoki Isobe (NASDA, MAXI Mission) Makoto Tashiro (Saitama Univ.) Kazuo Makishima (Univ. of Tokyo) Hidehiro Kaneda, Naoko Iyomoto (ISAS)

2. Lobes of Radio Galaxies Cygnus A (VLA 1.4 GHz) Nucleus Jet Hot Spot Lobe Huge electron and magnetic field energies time-integrated information on past activities of the jets

3. Emission from Lobes and Physical Parameters Radio Emission Synchrotron Radiation (SR) Flux : F SR ∝ u e u m V Index :  SR u e : energy density of electrons u m : energy density of magnetic fields V : Volume of the Lobe Comparing F SR and F IC u e and u m X-ray Emission Inverse Compton (IC) Scattering by SR electrons of the Cosmic Microwave Background (CMB) photons Flux : F IC ∝ u e u CMB V Index :  IC =  SR u CMB : energy density of CMB 4.1 x 10 –13 (1 + z) 4 erg cm -3

4. Discovery of IC X-rays from Lobes Fornax A (NGC 1316, Kaneda et al. 1995, Tashiro et al. 2001) IC X-Rays  X = 0.74 ～  SR u e =2 x 10 -13 erg cm -3 u m =4.6 x 10 -13 erg cm -3 (B=3  G) Nearly Equipartition 20’ = 135 kpc

5. Discovery of IC X-rays from Lobes Centaurus B (z = 0.01215, Tashiro et al. 1998) Color : GIS 1.5 -3 keV Contour : VLA 843 MHz (McAdam et al. 1991 ) u e = 2.4 x 10 -12 erg cm -3 u m = 3.8 x 10 -13 erg cm -3 (B ～ 3  G) Electron Dominant u e / u m = 6.3 10 arcmin (140 kpc)

6. ASCA Results 4C 73.08 (z = 0.0571) NGC 612 (z = 0.0290) Color : 0.5 – 2 keV Contour : 608 MHz 5 arcmin = 300 kpc Color : 0.7 – 3 keV Contour : 843 MHz (Jones & McAdam 1992) u e = 1.7 x 10 -13 erg cm -3 u m = 4.8 x 10 -15 erg cm -3 u e = 4.3 x 10 -13 erg cm -3 u m = 2.1 x 10 -14 erg cm -3 5 arcmin = 160 kpc

7. Chandra Results 3C452 (z = 0.0811) 3C427.1 (z=0.572) Pictor A (z = 0.0351) Color : 0.3–7 keV, Contour : 1.4 GHz 0.3 – 7 keV Color : 0.3 – 7 keV Contour : 1.4 GHz 2 arcmin = 160 kpc 10 arcsec = 50 kpc 2 arcmin = 80 kpc (Isobe et al. 2002 ApJL)

8. Chandra Results 3C452 (z = 0.0811) Thermal Comp. kT ～ 1 keV PL comp.  X = 0.65 ～  SR IC X-rays from the SR electrons

9. Chandra Results 3C452 (z = 0.0811) 3C427.1 (z=0.572) Pictor A (z = 0.0351) Color : 0.3–7 keV, Contour : 1.4 GHz 0.3 – 7 keV Color : 0.3 – 7 keV Contour : 1.4 GHz u e =2.1 x 10 -12 erg cm -3 u m =7.7 x 10 -14 erg cm -3 u e =3.0 x 10 -10 erg cm -3 u m =7.4 x 10 -12 erg cm -3 u e =4.6 x 10 -12 erg cm -3 u m =1.3 x 10 -13 erg cm -3 2 arcmin = 160 kpc 10 arcsec = 50 kpc 2 arcmin = 80 kpc

10. XMM-Newton Results Centaurus B (Tashiro et al. in preparation) 3C 98 (z = 0.0306) (Isobe et al. in preparation) Color : 0.3 – 10 keV Contour : 4.8 GHz u e =5.1 x 10 -12 erg cm -3 u m =1.7 x 10 -13 erg cm -3 2 arcmin = 70 kpc

11. u e and u m in Radio Lobes u e [erg cm -3 ] u m [erg cm -3 ] 100  G 10  G 1  G Equipartition u e = u m u e = 100 u m u e > 10 u m ～ Large Lobes > 100 kpc Small Lobes < 50 kpc  e = 10 3 – 10 5

12. Total Energies in Radio Lobes Electron Energy : u e V [10 58 erg] Magnetic Energy : u m V [10 58 erg] Equipartition u e V= u m V u e V = 100 u m V ～ 2 orders

13. Luminosity of Nucleus L X [10 40 erg s -1 ] Electron Energy u e V [10 58 erg] Relation to the Nucleus –electron energy- ueV ∝LXueV ∝LX

14. Magnetic Energy u m V [10 58 erg] Luminosity of Nucleus L X [10 40 erg s -1 ] Relation to the Nucleus –magnetic field- u m V seems independent of L X (nearly constant ?)

15. Spatial Distribution of IC X-rays Chandra Observation of 3C 452 X-ray Profile relatively uniform Radio Profile rim-brightening Point Sources

16. Spatial Distribution of Physical Parameters u e /u m ～ 100 Equipartition F SR F IC ∝um∝um

17. Spatial Distribution of Physical Parameters Fornax A Centaurus B Radial Profile of IC X-rays and SR radio u m /u e map

18. Summaries  With ASCA, Chandra and Newton, we have detected the IC X- rays from the lobes of numbers of radio galaxies, and accurately determined u e and u m in these lobes.  u e tend to dominate u m typically an order of magnitude.  The electron energy, u e V, seems to be proportional to the nuclear luminosity, although the magnetic energy, u m V seems independent.  In several lobes, the electrons are relatively uniformly distributed, although the magnetic fields seem to be compressed toward the edges of the lobes.  All of these results strongly indicates that the electrons (i.e. particles) pay more important roles in the formation of the jets, and/or the evolution of the radio galaxies/lobes.

19. Please e-mail to isobe@oasis.tksc.nasda.go.jp