The cosmological evolution ofblazars and the cosmic gammaray background in the Fermi era
Yoshiyuki INOUE (Kyoto, JSPS fellow DC1)
Collabolators：Tomonori Totani, Susumu Inoue (Kyoto),
Masakazu. A. R. Kobayashi (NAO),
Jun Kataoka (Waseda), Rie Sato (JAXA)

Fermi Symposium1

E^2 dJ/dE (keV/cm^2/s/sr)

What’s the origin of the cosmic
gamma-ray background?
1. MeV Background
AGNs (Rogers & Field ’91; Field & Rogers ’93;
Stecker, Salamon, & Done ’01; YI, Totani, &Ueda’08)

Supernovae (Clayton & Ward ‘75; Zdziarski‘96; Watanabe+‘99)

MeV Dark Matter annihilation (Ahn &Komatsu ’06, Rasera+‘06; Lawson & Zhitnitsky‘07 )MeV Blazars (Ajello+’09)

AGNs

2. GeV BackgroundBlazars (Stecker & Salamon ’96; Chiang &keV

MeVGeV

Mukherjee ’98; Mücke & Pohl 00; Narumoto &Totani ’06; Dermer ’07; YI & Totani ’09)

Galaxy Cluster Merger (Loeb & Waxman‘00; Totani & Kitayama ’00)

GeV Dark Matter annihilation (e.g. Odaet al. ’05)

Energy (keV) Sreekumar et al. 1998

2

What is BLAZAR?

SED Sequence

49

Blazar
LogLog(νL10 10νi[erg/s])iL(erg s-1)

48
47
46
45
44
43

Synchrotron

InverseCompton
GeV

42
41-5

http://www.nasa.gov/

05
10Log10 Ea (eV) [eV])
Log10 (Energy(Fossati+’97,’98; Kubo+’98; Donato+’01, but see also Padovani+’07)

3

Blazar Gamma-ray Luminosity Function(YI & Totani ’09)
Basic assumptions for blazar GLF construction•Blazar SED sequence.
•AGN X-ray Luminosity Function (Ueda+’03:hereafter U03).
Assuming “Ljet, bol ∝Ldisk, X “.

Constraining GLFs from EGRET data.
1.8

Redshift Distribution

0.8

1.6
1.2
1
0.8

0.7
U03(q)
U03(q,γ1)
H05(q)
H05(q,γ1)
EGRET blazars

0.6

0.5
0.4
0.3

0.4

0.2

0.2

0.1

00
0.01

0.1
Redshift
Redshift z z

U03(q)
U03(q,γ1)
H05(q)
H05(q,γ1)
EGRET blazars

0.6

dN/d(log10 Lγγ))
dN/log(LdN/d(logdN/log(z)
10 z)

1.4

Luminosity Distribution

143

44454647
48
log(Llog10 (L[erg s-1])γ γ[erg/s])

49504Cosmic X-ray and Gamma-ray Backgroundbefore the Fermi era
2-1 -1
2/s/sr)E22dN/dE
dN/dE
E(MeV(MeV/cm
cm-2 s-1 MeVsr )10-1

Blazar: U03 (q, γ1)
Non-blazar (Γ=3.5): ITU08
Non-blazar (Γ=3.8): ITU08
Blazar + Non-blazar (Γ=3.5)
Blazar + Non-blazar (Γ=3.8)
HEAO-1
EGRET (S98)
EGRET (S04a)
Swift/BAT
EGRET (S98+S08)
SMM
COMPTEL

10-2

10-3

non-blazar
AGNs(YI+08)
X-ray

10-4 -2
10

10-1

MeV
100

Blazars ( YI & TT 09)
GeV
101102103PhotonEnergy(MeV)
Energy(MeV)

Above GeV, our model does not reproduce
observational data.

104

105

106

YI & TT 09
arXiv:0810.3580
5Cosmic X-ray and Gamma-ray Backgroundin the Fermi era
2-2 -1 2 -1 -1
E2E2dN/dE(MeV/cm/s/sr)
dN/dE (MeV cm s MeVsr )10-1

Blazar: U03 (q, a1)
Non-blazar (K=3.5): ITU08
Non-blazar (K=3.8): ITU08
Blazar + Non-blazar (K=3.5)
Blazar + Non-blazar (K=3.8)
EGRET (S98)
EGRET (S04a)
EGRET (S98+S08)
Fermi

10-210-3

non-blazarAGNs(YI+08)

Fermi Data from
TeV conf. on JulyBlazars ( YI&TT09)
10-4
10-2

X-ray
10-1

MeV100

GeV
101

102

103

PhotonEnergy(MeV)
Energy(MeV)

Our prediction matched very wellwith the Fermi data.

104

105

106

YI & TT 09
arXiv:0810.3580
6E2 dN/dE (MeV/cm2/s/sr)

Non-blazar AGNs vs. Blazars

Blazars
Non-blazar
AGNs

Ackermann+’09 at TeV. conf.

<~10 MeV:•smooth connection toCXB•likely to be non-blazar
AGNs>~10 MeV:•distinct SED from CXB•likely to be blazars•MeV-blazar contribution at<~10 MeV? (Ajello+09)•fine-tuning required forSED•distinct blazar population
required between MeV andEnergy (MeV)
GeV.

Expected Number of Fermi AGNs
• One-year survey
810~800 blazars•Non-blazar Fermi
107
1~10
non-blazarAGNs
•
Fermi
AGN
6
10
Five-yearsurvey
EGRET
•
5
104 Blazar
EGRET• ~1200 blazars
10103• 4~50 non-blazar AGNs
Blazar: U03(q,γ1)210Non-blazar (Γ=3.5)• Nonthermal gamma-ray-1-1 ]N(>Flux)[(4πsr)N (>Flux) [(4 π sr) ]109

flux from NGC 4151, thebrightest Seyfert AGN

101Non-blazar (Γ=3.8)
Blazar + Non-blazar (Γ=3.5)
010 Blazar + Non-blazar (Γ=3.8)

10 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 • Flux(>100 MeV): ~1e-8 γ/cm/s
10 10 10 10 10 10 10 10 10 10 10-1-2 -1

Flux (>100MeV)[photons cm scm] -2 s-1]
Flux(>100MeV)[photons• Photon Index: ~3.58

-1]-2-2-1 -1-1
Fγ dN/d(logF)[photonscmssr]
FdN/d(logF)[photonscmssr
1010 γWill Fermi resolve the cosmic
gamma-ray background?
10-5

Non-blazar
AGN
10-6

Fermi

resolve• ~99% of the

10-7

Fermi
EGRET
EGRET-8

10Blazar

10-9

10-14

10-13

10-12

10-11

background flux
from blazars (>100MeV).

• ~0.01% of thebackground flux
from non-blazar
AGNs (>100 MeV).

Blazar: U03 (q,γ1)
Non-blazar (Γ=3.5)
Non-blazar (Γ=3.8)
Blazar + Non-blazar (Γ=3.5)
Blazar + Non-blazar (Γ=3.8)

10-10
10-11 -15
10

• Five year survey will

10-1010-910-8-2 -1

10-7

10-6-2 s-1]
Flux (>100MeV)[photons cm s cm]
Flux(>100MeV)[photons9

Fermi blazar @ z~71000~5-years -9survey2

Flim(>100MeV)=1×10 photons/cm /s

100N(>z)•Predictions for z~7U03(q)U03(q,a1)
U03(q,a1): p2=3.5

YI&TT09
10 +SDSS

blazar detectability•based on IT09
•improved atYI&TT09
z~7high-z based on
SDSS quasar LF
upto z~6.

1

0.1
02

468101214z z
Redshift~1 blazar @ z~7 with ~5-year Fermi survey (YI+in prep.).

10Probing high-z universe through GeV
gamma-ray attenuation
100

z=0.1
z=0.1

z=0.3
z=0.3

z=1.0
z=1.0

z=3.0
z=3.0

10

Optical Depth o

Optical Depth

11++e-.
γ+γe• (>GeV) UV→
GeV flux attenuatedby high-z UVbackground (Oh ’01,Gilmore+09, S.Inoue+09).

•information of early

0.1
100
z=5.0
z=5.0

z=6.0
z=6.0

z=7.0
z=7.0

10

star/galaxy formation
Semi-analyticalmay be obtained.
model

Mitaka model
Kneiske+04
Kneiske+04
S.Inoue+09
S.Inoue+0911•Red model: consistent withz<5 data (e.g. galaxy LF)•Blue model: consistent0.1
1

10100

1

10100

1

Energy (GeV)

10100

with z>5 data (e.g.
reionization data)(YI+in prep.)11

Summary 1•New blazar GLF (Y. Inoue & Totani ’09, arXiv:0810.3580)•Blazar SED sequence incorporated•Non-trivial prediction for the cosmic gamma-raybackground•Our prediction matched very well with the Fermi data.
•AGNs are the primary sources as the origin of cosmic Xray/Gamma-ray background.

12Summary 2•Fermi will find•~800 blazars and 1~10 non-blazar AGNs in 1-year survey,•~1200 blazars and 4~50 non-blazar AGNs in 5-year survey.
•Fermi will resolve•~99% of the gamma-ray background from blazars (>100MeV),•~0.01 % of the gamma-ray background from non-blazar
AGNs (>100 MeV).

• ~1 blazar @ z~7 may be found by Fermi.
•A new key to understanding the high-z cosmic evolution.
13