低光度活動銀河核での乱流加速と高エネルギー粒子放射1) SSK, Murase, & Toma, 2015, ApJ. 806, 1592) Murase & SSK in prep.
3) SSK, Toma, Suzuki, & Inutsuka in prep.

木村成生（東北大学）
共同研究者
當真賢二（東北大学）
村瀬孔太（Penn. State. Univ.）
鈴木建（名古屋大学）
犬塚修一郎（名古屋大学）

log (νLν /erg

-13

ARI

低光度活動銀河核(LLAGN)

15 July 2008

10 cm

1 cm

log Lbol /LEdd < –3

1 mm

100 µm 10 µm

1 µm(Ho ’08)log (νLν /ergs s–1)

–3 ≤ log Lbol /LEdd < –1

12:45

Spectral Energy Distribution
46log Lbol /LEdd ≥ 0–1 ≤ log Lbol /LEdd < 04038

re 72429101112131415161718log (ν/Hz )Schematic picture1000 Å 0.1 keV 1 keV10 keV

wind

wind

jet

QSOs

44

LLAGN x 104

thin disk

42

thin disk
hot plasma

BH

hot plasmalog Lbol /LEdd ≥ 0–1 ≤ log Lbol /LEdd < 040–3 ≤ log Lbol /LEdd < –1log Lbol /LEdd < –338

9101112131415161718

wind

jet

windlog (ν/Hz)Blue Bump がない → 標準円盤がないof Astronomy and Astrophysics. The quasars (open circles) have a bump, whiーー＞ 輻射非効率降着流(RIAF)

Figure 1.2: Upper panel: The average SED for radio-quiet AGNs binned by Edd

posite SEDs for radio-quiet AGNs binned by Eddington ratio. The SEDs arenormalized
at from1 µm.Figure 7 of Ho (2008) with a permission from the author and t
figureis takenpted from L.C. Ho, in preparation.)squares)havea&dipPeng
in the ultraviolet range. Lower panel: The schematic pictuei (Ho 1999b, 2002a; Ho et al. 2000) anda substantial
fractionof Seyfert
nuclei(Ho(Narayan&Yi94, Yuan
+ 03,Abramowicz& Fragile 13, Yuan & Narayan 14)). Defining radio-loudness based on the relative strength of the radio
andis X-rayemission, flow around an SMBH, and a thin disk is in the outer reg
Therea hot accretion≡ ν Lν (5 GHz)/LX , Terashima & Wilson (2003b) also find that LINERs tend to be radioand winds around the SMBH. The arrows show the flow directions of the plasma.
here taken to be RX > 10−4.5 . Moreover, the degree of radio-loudness scales inversely withLEdd (Ho 2002a; Terashima & Wilson 2003b; Wang, Luo & Ho 2004; Greene, Ho & Ulvestad (Mahadevan & Quataert 97)

高温 & 希薄ーー＞ クーロン衝突は非効率

0.09

込まれる (降着円盤 or 降着流).

•9.25 0213 -343

350 0.49

7.13

吸い込まれる (降着円盤 or 降着流).

3

磁気回転不安定と粒子加速出する.

1.27

Torbit=6.62

スの重力エネルギーが変換され, 明るく輝き, 場合によってはジェット•ガスの重力エネルギーが変換され, 明るく輝き, 場合によってはジェットを噴出する.
巨大ブラックホールz/λエネルギー天体のエネルギー源

Plasma Particle simulation(PIC)
ジェット(赤)Balbus & Hawley’91白鳥座X-1の想像図-1.27座X-1の想像図

降着円盤線で光る)

高エネルギー天体のエネルギー源•(太陽質量の１億倍)

0

MHD simulation ジェット(赤)(Fluid)
銀河(白)

0.21

9.68 0247 -158

1.270z/λTorbit=6.81

155 0.61

2.23

7.95
電波銀河
6.81の観測6.05

5.86
2011年10月12日水曜日-1.27

Torbit=0.09

0.3
乱流場発達

12.50Maxwellian

329 -58乱流場発達
51 0.65

1.27

Sano, Inutsuka, Turner, Stone ’04

Torbit=7.95

computational domain. However, model Z62p has an initially
uniform field that is localized within a small part of thedomain. At the beginning, the magnetic field is confined to!0:5 < x < 0:5 and !1 < y < 1 and fills one-quarter of thevolume of the box. The field strength and the other parameters
are exactly the same as model Z62. The time evolution of the（See also, Machida, Nakamura, & Matsumoto 01;
Ohsuga & Mineshige 11; Sadowski, Narayan + 13;
Bai & Stone 14)-1.27

0z/λmoe銀河(白)ブラックホール
電波銀河 (太陽質量の10倍程度)
恒星(可視光で光る)の観測

el is started with a localized vertical field, uniform in !0:5 < x < 0:5 and !1 < y < 1.
d direction of the poloidal magnetic field. The MRI enlarges the magnetized region, andlt
e– 35 –

降着円盤
(X線で光る)

ブラックホール(太陽質量の10倍程度)(可視光で光る)水曜日

巨大ブラックホール(太陽質量の１億倍-1.270x/λ

5.48
5.39

Power-law
2.83

Fig. 7.— Evolution of energy spectra for the plasma= 1536. The initial stage
Torbit = 0.09 shows a cold drift Maxwellian distribution function with a Keplerian motAt Torbit = 5.39 just before the onset of magnetic reconnection, the spectrum still rema hot Maxwellian-like distribution function. At Torbit = 5.48 just after the onset of recnection, high-energy, nonthermal particles are generated. At Torbit = 7.95 the high ene
component can be approximated by a power-law function with N (")d" / " 1 .

Hoshino 13, Hoshino 15(see also Riquelme+’12)

乱流磁場のリコネクション→非熱的な宇宙線陽子
(CR)
1.27
-1.27 01.27 -1.27 0
1.27-1.27 生成
0
1.27x/λx/λx/λ4

非熱的粒子の反応 �p+p ! p+p+Aπ0+Bπ±�
p+γ ! p+p+π0�
p+γ ! p+n+π+�
π0 ! 2γ, π± ! 3ν+e±�

Hot#PlasmaBHcf.) Niedzwiecki, Xie, Stepnik 13pγ�

ν�

pπ

Turbulent#Field##!#proton#accelera4on

高温降着円盤は高エネルギーニュートリノ源かつγ線源

astrophysical neutrino flux, respectively. The prompt atmosphericflux is fitted to zero, we show the 90% C.L. upper limit on thiscomponent instead (green line).

天体ニュートリノの観測

Aartsen et al. ’13・IceCube が拡散ニュートリノの検出を報告

104105106

起源天体は不明�ー＞�RIAFはどうか？

Figure 6. Best-fit astrophysical neutrino spectra (all flavors combined). The red shaded area corresponds to the 68% C.L. allowed

5Fa⌫tcrcuincbt

RinPorcapec“6accretion, which is typically 0.1 mp c2 per a proto
assume only a small fraction of protons are inje
relativisticenergyaccretion, which is typically 0.1 mp c2 pera proton.
We through some plasma processe
assume only a small fraction of protons
as arethe injectedmagnetictoreconnection (Hoshino 2013, 201
relativistic energy through some plasma
processes,
such
those
relativistic
governed2015
by the F
SSK,protons
Murase,are& Toma,as the magnetic reconnection (HoshinoPlank
2013, 2015),
and(e.g., Stawarz & Petrosian 2008),
equationthose relativistic protons are governed by the Fokker# !
"•∂1 ∂∂pPlank equation (e.g., Stawarz & Petrosian 2008),
2F (p) = 2
p Dp F (p) +F (p)# !
"$∂tp ∂p
∂ptcool∂1 ∂∂p%&F (p) = 2
p2 Dp F (p) +F (p) − F (p) t−1 + t−1 + Ḟinj ,diﬀfall∂tp ∂p∂ptcool% −1 6 −1 &Kimura,
M落下 function
冷却 F (p) (15)is the拡散
distributionof th− F (p) tdiﬀ +加速tfall + Ḟinj , where2
thermal protons (dNpE/dE=4πEF (p)c) , p is t
ppcritlog(t [sec])
where F (p) is the distribution functionof thenonmentumoftheprotons, Dp is the diﬀusion coeﬃc2
thermal protons � (dNmo
p /dEp = 4πEp F (p)c) , p is thepγγ�
themomentum
space, Ḟinj is the injection term,
0+Bπ±�
p+p !
p+p+Aπν�
mentum0� of the protons, Dp is the diﬀusion
coeﬃcient
for tSynch. time, and t
thecoolingtime,isthediﬀusionp
diﬀfa
p+γ ! p+p+πTarget photon thespectra
emittedbythermal
electrons
momentumspace, Ḟinj is the injectionterm,tcool is+�infalltime.
p+γ!
p+n+π
he red-solid,0 thegreen-dashed,andt blue-dottedlines± ! 3ν+e±�
thecoolingtime,
isthe
diﬀusiontime,Whenand tfall
isconsider
thediﬀπ!
2γ,πwe
the relativistic particles, weA1(reference),
A2(lowṁ),A3(highM),
respecBH
electrons
infall
time.
pp
arget
photon spectrum
for model A4 is the same withcomparetheCoulomb loss time for relativistic p
冷却tted lines
Hot#PlasmaWhen we consider
shouldπ the relativistic particles,), respectCoul towetfall
. The Coulomb loss time is estimatedame withcompare the Coulomb loss time for relativistic
particles
拡散(e.g., Dermeret al. 1996)
higher than thatfor
A1.
Whentheelectron
tCoul to tfall . The Coulomb loss time is estimated to be
BHe is higher withfixedṁ, they parameterbe3/2p(e.g.,Dermer
etal.
1996)
Turbulent#Field##(γ−1)(3.8θ+ 1.0) R
electronep
落下 tr. Thus, the spectrum is harderfor higher β!#proton#accelera4on
≃ 1225
Coul 加速eter
be3/2
τT ln Λcδe .
(γ−1)(3.8θ+1.0)
Replog(Ehigher βp[GeV])
tCoul ≃ 1225
−1 3/2
7 3/2c ∼ 7 × 10 r1 α−1 MBH,7 ṁ−2 θe γp,1 s
CTRA OF NON-THERMAL PARTICLES IN AτT ln Λimura, Murase, & Toma

LLAGN MODELRIAF内での乱流加速→非熱的陽子のスペクトルを計算

TYPICAL RIAF

3/2−1 3/2
7∼
7×10r
αM
ṁ
γp,1 sγp is (16)the Lorentz factor of the proton.
−1 BH,7 −2 θewhere1NA
3.1. Plasma in accretion flows
tCoul > tfall is satisfied for RIAFs, we can negl
where γp is the Lorentz factor of theCoulombproton. lossSincein RIAFs.
fall time tfallt is shorter
thantherelaxation> tis satisfied for RIAFs, we can neglect the

最高エネルギーは加速と拡散的逃走の釣り合いで決まる

LLAGN MODEL
SSK, Murase, & Toma, 2015 �p+p ! p+p+Aπ0+Bπ±�
p+γ ! p+p+π0�
p+γ ! p+n+π+�
π0 ! 2γ, π± ! 3ν+e±�

Hot#Plasma
BH

pγ�

7
ν�p

π

Turbulent#Field##!#proton#accelera4on

log(Eν2Φν [GeV/cm2/s/sr])log(Eν2Φν [GeV/cm2/s/sr])

pp卓越pγ卓越log(Eν[GeV])

log(Eν[GeV])

・LLAGNモデルはIceCube eventの一部を説明可能
・片側は別の天体の寄与と考えられる(e.g., Starburst Galaxies, Low Luminosity GRBs)

近傍のLLAGNの観測可能性
Murase & SSK in prep.

•

近傍LLAGNを点源として観測できないか？

•候補天体
Sgr A*,

d~8 kpc

1型LINER

M81,

NGC3998

d~4 Mpc
d~14 Mpc

近傍のLLAGNの観測可能性
Murase & SSK in prep.

•

近傍LLAGNを点源として観測できないか？

•候補天体
Sgr A*,

1型LINER

M81,

NGC3998

藤田さんの講演

d~8 kpc

d~4 Mpc
d~14 Mpc

近傍のLLAGNの観測可能性
点源ニュートリノ源としての観測可能性

M81

N (E > Eμ )Murase & SSK in prep.

NGC3998

1Eμ [eV]

次世代ニュートリノ望遠鏡なら検出できる �p+p ! p+p+Aπ0+Bπ±�
p+γ ! p+p+π0�
p+γ ! p+n+π+�
π0 ! 2γ, π± ! 3ν+e±�

Hot#PlasmaBHpγ�ν�pπ

Turbulent#Field##!#proton#accelera4on近傍のLLAGNの観測可能性
RIAFからのガンマ線の観測可能性

M81

Murase & SSK in prep.

NGC3998log(EγFγ [erg/cm2/s])

Ecut

Thermal electronlog(EγFγ [erg/cm2/s])

2γ —> e+esync.
casc.

Ecut

Thermal electron

2γ —> e+e--11

π—>2γ -12sync.
casc.

π—>2γ-13

protonsync.

protonsync.

8 10log(Eγ [eV])

一回カスケードでGeV付近にピークがくる→ Fermi で検出できる可能性

810 �p+p ! p+p+Aπ0+Bπ±�p+γ ! p+p+π0�
p+γ ! p+n+π+�π0 ! 2γ, π± ! 3ν+e±�

Hot#Plasma
BH

pγ�

ν�pπ

Turbulent#Field##!#proton#accelera4on近傍のLLAGNの観測可能性•TeV halo 形成？
・ハドロンモデルでPeVのニュートリノ生成→ 10PeV中性子もほぼ同量発生・10PeV中性子は~pc 程度走って崩壊→10TeVの電子を放出
・放出された電子が赤外線光子を逆コンプトン→ ~ pc scale に広がったsubTeV - TeV の光子を放出
pγppAGN coreneIRe乱流加速シミュレーション
SSK, Toma, Suzuki, & Inutsuka in prep.

• ここまでの話は全て加速を現象論的に取り扱っている

降着円盤の乱流場に適用して良いかは自明でない→数値計算による乱流加速モデルの検証も重要• 「MHD計算によるMRI乱流場の生成」と「テスト粒子計算による粒子軌道の時間発展」の２つを組み合わせた数値実験を行う

乱流加速シミュレーション
SSK, Toma, Suzuki, & Inutsuka in prep.

• ここまでの話は全て加速を現象論的に取り扱っている

降着円盤の乱流場に適用して良いかは自明でない→数値計算による乱流加速モデルの検証が重要
粒子のエネルギーの時間進化x

MRI乱流場の磁場強度分布

E/E0• 「MHD計算によるMRI乱流場の生成」と「テスト粒子計算による粒子軌道の時間発展」の２つを組み合わせた数値実験を行う

yt/tgyro

まとめ•

LLAGNの高温降着円盤は HE ν、γの起源天体と成り得る•

LLAGNモデルはIceCube events の一部を説明可能•

次世代ニュートリノ望遠鏡で点源として検出可能•

近傍のLLAGNはフェルミで検出の可能性あり•

AGN周りに逃走中性子によるTeV halo 形成の可能性•

降着円盤中での乱流加速理論も重要→ 数値シミュレーションにより理論モデルを検証中

ありがとうございました