Particles and Fields in Lobes of Radio Galaxies

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)

Lobes of Radio GalaxiesCygnus A (VLA 1.4 GHz)

NucleusJet

Hot Spot

Lobe

Huge electron and magnetic field energiestime-integrated information on past activities of the jets

Emission from Lobes and Physical Parameters

Radio Emission Synchrotron Radiation (SR)

Flux : FSR ∝ ueumV Index : SR

ue : energy density of　 　 　 　 　 　 　 　 　 　 　 　electronsum : energy density of magnetic fieldsV : Volume of the Lobe

Comparing FSR and FIC

ue and um

X-ray Emission Inverse Compton (IC) Scattering by SR electrons of the Cosmic Microwave Background (CMB) photons

Flux : FIC ∝ ueuCMBV Index : IC = SR

uCMB : energy density of CMB4.1 x 10 –13 (1 + z) 4 erg cm-3

Discovery of IC X-rays from LobesFornax A (NGC 1316, Kaneda et al. 1995, Tashiro et al. 2001)

IC X-Rays

X = 0.74 ～　 SR

ue=2 x 10-13 erg cm-3

um=4.6 x 10-13 erg cm-3 (B=3 G) Nearly Equipartition

20’ = 135 kpc

Discovery of IC X-rays from LobesCentaurus B (z = 0.01215, Tashiro et al. 1998)

Color : GIS 1.5 -3 keVContour : VLA 843 MHz (McAdam et al. 1991 )

ue = 2.4 x 10-12 erg cm-3

um = 3.8 x 10-13 erg cm-3

(B ～ 3 G)

Electron Dominantue / um = 6.3

10 arcmin(140 kpc)

ASCA Results4C 73.08 (z = 0.0571) NGC 612 (z = 0.0290)

Color : 0.5 – 2 keVContour : 608 MHz

5 arcmin = 300 kpc

Color : 0.7 – 3 keVContour : 843 MHz (Jones & McAdam 1992)

ue = 1.7 x 10-13 erg cm-3

um = 4.8 x 10-15 erg cm-3 ue = 4.3 x 10-13 erg cm-3

um = 2.1 x 10-14 erg cm-3

5 arcmin = 160 kpc

Chandra Results3C452 (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 keVContour : 1.4 GHz 2 arcmin = 160 kpc

10 arcsec= 50 kpc

2 arcmin = 80 kpc

(Isobe et al. 2002 ApJL)

Chandra Results3C452 (z = 0.0811)

Thermal Comp.kT ～ 1 keV PL comp.

X = 0.65 ～ SR

IC X-rays from the SR electrons

Chandra Results3C452 (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 keVContour : 1.4 GHz

ue=2.1 x 10-12 erg cm-3

um=7.7 x 10-14 erg cm-3

ue=3.0x10-10

erg cm-3

um=7.4x10-12

erg cm-3

ue=4.6 x 10-12 erg cm-3

um=1.3 x 10-13 erg cm-3

2 arcmin = 160 kpc

10 arcsec= 50 kpc

2 arcmin = 80 kpc

XMM-Newton ResultsCentaurus B

(Tashiro et al. in preparation)

3C 98 (z = 0.0306)

(Isobe et al. in preparation)

Color : 0.3 – 10 keVContour : 4.8 GHz

ue=5.1 x 10-12 erg cm-3

um=1.7 x 10-13 erg cm-3

2 arcmin = 70 kpc

ue and um in Radio Lobes

ue [erg cm-3]

um [

erg

cm-3]

100 G

10 G

1 G

Equipartitionue = um

ue = 100 um

ue > 10 um～

Large Lobes> 100 kpc

Small Lobes< 50 kpc

e = 103 – 105

Total Energies in Radio Lobes

Electron Energy : ueV [1058 erg]

Mag

net

ic E

ner

gy :

umV

[10

58 e

rg]

EquipartitionueV= umV

ueV = 100 umV

～ 2 orders

～2

ord

ers

Luminosity of Nucleus LX [1040 erg s-1]

Ele

ctro

n E

ner

gy u

eV [

1058

erg

]

Relation to the Nucleus –electron energy-

ueV ∝ LX

Mag

net

ic E

ner

gy u

mV

[10

58 e

rg]

Luminosity of Nucleus LX [1040 erg s-1]

Relation to the Nucleus –magnetic field-

umV seems independent of LX

(nearly constant ?)

Spatial Distribution of IC X-rays Chandra Observation

of 3C 452

X-ray Profile relatively uniformRadio Profile rim-brightening

Point Sources

Spatial Distribution of Physical Parameters

ue/um ～ 100

Equipartition

FSR

FIC∝ um

Spatial Distribution of Physical ParametersFornax A Centaurus B

Radial Profile of IC X-rays and SR radio

um /ue map

SummariesWith ASCA, Chandra and Newton, we have detected the IC X-rays from the lobes of numbers of radio galaxies, and accurately

determined ue and um in these lobes.

ue tend to dominate um typically an order of magnitude.

The electron energy, ueV, seems to be proportional to the nuclear

luminosity, although the magnetic energy, umV 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.

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