AGN種族と宇宙ガンマ線背景放射
YI, Totani, & Ueda ‘08
YI & Totani ’09
YI ’11

Yoshiyuki Inoue(Kyoto Univ.)1Gamma-ray Sky Map

Numerous sources are buried in the extragalactic
gamma-ray background (EGRB).

EGRB Spectrum
Ackermann+’09 at TeV. conf.

EGRB is the integrated gamma-ray emission fromgamma-ray emitting sources over the cosmic history.
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EGRB above 100 MeVBlazars (AGN) are expected to make a significant
contribution to EGRB
(see e.g. Stecker & Salamon ’96, Chiang & Mukherjee ’98, Mücke & Pohl ’00,Narumoto & Totani ’06, Dermer ’07, Kneiske+’08, YI & Totani ’09)

~22% of EGRB is from blazars (Abdo+’10)~78% of EGRB is unknown.
Starburst galaxy (Pavlidou+’02, Thompson +’07, Fields+’10, Makiya+’11)

Radio-quiet AGNs (YI+’08)
Dark Matter
And more...
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Various AGN Populations

http://www.nasa.gov/

5Gamma-ray Loud Radio Galaxy (YI’11)
No. 1, 2010

FERMI LAT VIEW OF MAGNs

919

11 radio galaxies detectedby Fermi (Abdo+’10)

they would contribute toEGRB.
gamma-ray luminosity
function (GLF) is required.
but, too few samples.

Abdo+’10Figure 6. Spectral slopes of FRI radio galaxies (red circles), FRII radio sources(green squares), BL Lac objects (open blue circles), and FSRQs (open blacksquares) are plotted as a function of the γ -ray luminosity (100 MeV–10 GeV).
Local radio galaxies (z < 0.1) and blazars occupy different regions of theplot, with misaligned AGNs generally characterized by lower luminosity. On

radio luminosity function
is well studied (Dunlop &Figure 7. Histogram showing the luminosity distribution of misaligned AGNs
(upper panel : FRIs—red continuum line, FRIIs—green dashed line) and blazars(lower panel: BL Lac objects—blue continuum line; FSRQs—black dashedline). FRI radio galaxies are significantly less luminous than BL Lac objects.
The broad-line radio galaxy 3C 111 is the only FRII outside the luminosity
range covered by the FSRQ

Peacock ’90, Willot+’01)

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Correlation between Radio andGamma-ray Luminosities
gamma-ray luminosity
correlate with radioluminosity:

1.16
Lγ ∝ L5GHz

GLF is derived by using
this correlation.
the index is similar to thatof Fermi blazars (Ghirlanda+’10) :1.07
Lγ ∝ L20GHz

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Source Count Distribution
GLF is normalized tothe number of theFermi radio galaxies.
detection efficiency
is corrected (Abdo+’10).
gamma-ray loudpopulation is ~8% ofradio galaxies.

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EGRB from radio galaxies

SED : broken power-law, EBL model : Finke+’10~25 % of the unresolved EGRB
with a factor of 2.5 uncertainty.
~47 % will be explained by radio-loud AGNs, blazars(Abdo+’10) + radio galaxies (YI’11).

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E2 dN/dE (keV/cm2/s/sr)

Other AGN population:
radio-quiet AGN (YI+’08)

X-ray is from IC-scat. incorona.
assume non-thermal
electrons also exist.

w/ nonthermal

thermalMeV

expected non-thermal
electron distribution isclose to that observed insolar flares and Earth’s
magnetotail.

➡reconnection heating
Energy (keV)

corona (Liu, Mineshige, &Shibata ’02).

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Other AGN population: blazars

4+,(?#$@665$+@&##'#;,$$9(,"$&#3#;,$5#&(?+,(6;0$8+0#5$6;$A)>A!$

6,$+44$)*%$'65#40$,#0,#5$1#,$C#D@D$<,#3E#&FGH:$I"(+;@FGJ:$K#&'#&F/LM$(YI & Totani ’09; YI, Totani, & Mori ’10)
local GLF

source count3-2'%4%&(-5#Ajello+’11,(-./#012''/#!"#

SED: blazar sequence (Fossati+’98, Kubo+’98)
GLF is constrained by EGRET data.
our GLF
is consistent with Fermi FSRQ GLFs
predicted ~2 times lower source counts (BL Lacs?).

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Other AGN population: blazars(YI & Totani ’09; YI, Totani, & Mori ’10)

Total EGRB

~40 % of EGRB (resolved + unresolved) is explained.
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EGRB from various AGN populations(unresolved + resolved EGRB)AGN populations are dominant in X-ray and gammaray (~7 orders of magnitude in energy).

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What is the origin of EGRB?
no EBL absorption
signature up to 100 GeV.

No Abs.?

cosmological sources
have their evolution peakat z~1-2.
EBL optical depth is ~1
at ~100 GeV for z=1.
nearby or hard spec.
sources? (e.g. HBLs)
we need the EGRB
spectrum at higher energy(CTA?)
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What is the origin of EGRB?
no EBL absorption
signature up to 100 GeV.

No Abs.?

cosmological sources
have their evolution peakat z~1-2.
EBL optical depth is ~1
at ~100 GeV for z=1.
nearby or hard spec.
sources? (e.g. HBLs)

Dermer+’11

we need the EGRB
spectrum at higher energy(CTA?)
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What is the origin of EGRB?
no EBL absorption
signature up to 100 GeV.

No Abs.?

cosmological sources
have their evolution peakat z~1-2.
EBL optical depth is ~1
at ~100 GeV for z=1.
nearby or hard spec.
sources? (e.g. HBLs)we need the EGRB
spectrum at higher energy(CTA?)
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Cherenkov Telescope Array (CTA) is a next
generation TeV Cherenkov telescope.

http://www.cta-observatory.org/
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CTA	  計画（チェレンコフ望遠鏡アレイ計画）
従来より一桁高い感度

1000を超えるガンマ線源が広いエネルギー領域銀河系内・系外に発見されると予想される

Simula)on	  銀河面スキャン（HESS	  	  and	  CTA） 手嶋さんのスライドより

Conclusion~25 % of unresolved EGRB would be explained byradio galaxy population~8% of radio galaxies are gamma-ray loudpopulation.
AGNs contribute significantly to the cosmic X-ray/
gamma-ray background (~7 orders of magnitude!)
The rest of EGRB would be explained by nearby
sources or hard spectrum sources.
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