Non-thermal Coronal Activity
in Seyfert Galaxies
Yoshiyuki Inoue
Chiba Univ. Seminar @ Chiba, 2023-11-14

Introduction

Pathways to Discovery in Astronomy and Astrophysics for the 2020s• Two frontiers in Multi-Messenger Astronomy:• Gravitational Waves• Neutrinos

What are the origins of high energy neutrinos?

d spectrum for six years of HESE neutrino events starting inside the detector. The yellow and red bands show the 1 uncertainties on the
power-law fit. Superimposed is the best fit to eight years of the upgoing muon neutrino data (pink). Note the consistency of the red andre from Ref. [28]. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Flux E 2dN/dE [GeV/cm2/s/sr]≳ 100 Neutrinos (TeV-PeV) from the sky

Ahler & Halzen ‘18

Cosmic Background
Radiation Spectrum

10°4

10°5

10°6

10°7

X-ray Gamma-ray

Neutrino

10°8

10°9
10°6

10°4

10°2

100

102

104

Energy [GeV]de projection in Galactic coordinates of the arrival direction of neutrino events. We show the results of the eight-year upgoing track
th reconstructed muon energy Eµ & 200 TeV ( ). The events of the six-year high-energy starting event (HESE) analysis with depositedan 100 TeV (tracks ⌦ and cascades ) are also shown [28,98,99]. The thin circles indicate the median angular resolution of the cascade
blue-shaded region indicates the zenith-dependent range where Earth absorption of 100 TeV neutrinos becomes important, reaching moreo the nadir. The dashed line indicates the horizon and the star (?) the Galactic Center. We highlight−3 the four most energetic events in bothr deposited energy (magenta numbers) and reconstructed muon energy (red number). (For interpretation of the references to color in thise reader is referred to the web version of this article.)• Cosmic Neutrino Flux level = 0.1 × Cosmic GeV Gamma-ray Background (CGB)= 10

× Cosmic X-ray Background (CXB)• CXB and CGB are dominated by Active Galactic Nuclei (AGNs).

ic halo [47,48]. More exotic scenarios consider dark matter decay [49–55] in the Galactic dark matter halo. Most
arios also predict the production of pionic PeV gamma rays. These gamma rays are absorbed via pair production

106

IceCube detection of TeV neutrinos from NGC 1068

Evidence of Non-thermal Activity in a Seyfert galaxy

SignalBackground

Total
Data

80

#Events

60
40
20

IceCube2022
Figure 1: Skymap of the scan for point sources in the Northern Hemisphere. The color scale

0

1

2
3
ˆ2 [deg2 ]4

IceCube 2022

represents the local p-value obtained from the maximum likelihood analysis evaluated (with thespectral index as free fit parameter) at each location in the sky, shown in Equatorial coordinates
Figure2: indicate
The skyregionthemostin significant spot in the Northern Hemispherewith Hammer-Aitoff projection. The black
circles
the threemostaroundsignificant
objects
the source list search. The circle of NGC
1068
also coincides
withleftthe plotoverallhottestaspot
the of the region around the hottest spot. The spot
andNGC
1068. Theshows
fineinscan

What is NGC 1068?

An obscured Seyfert galaxy with a weak jet activity

ALMA Image©NASA, ESA & A. van der Hoeven

Michiyama, YI, +’22

Where is the neutrino production site?

“Neutrino ux > Gamma-ray ux” = Gamma-ray Optically-Thick Region• Target photons : X-ray (~ 1 keV)
ϵ
X
−1
−1
5
τ
≈
ϵ
L
R
≃
10
γγ
X
X
•
( 1 keV )
4πc

−1

σγγ

IceCube

LX Rs
LEdd R• Host galaxy : Unlikely

Fermi• X-ray binaries : Not enough(see Swartz+’11, YI+’21)• Seyfert Corona (~10-100 Rs) : Most Likely

IceCube2020
FIG. 9: The best-fit time-integrated astrophysical power-law neutrino flux obtained u
flflselection in the direction of NGC 1068. The shaded regions represent the 1, 2 & 3 er

Neutrino Emission from Seyfert Corona

High energy particle acceleration in AGN corona region?

NGC 1068: a cosmic obscured accelerator
THIS WORK• ϕνμ+ν̄μ(1.5 − 15 TeV) ∼ 4 × 10

−112

erg/cm /s• Lνμ+ν̄μ(1.5 − 15 TeV) ∼ 10 erg/s
42➡ LCR( > 10 TeV) ∼ 10 erg/s
43

(2)

(1)

Fermi-LAT• Note: LX ∼ 3 − 7 × 10 erg/s
43

MAGIC

• If cosmic rays exist in corona region,• pp and/or pγ interactions can
produce neutrino emission.

© IceCube(1) Y. Inoue et al., ApJL’20(2) K. Murase et al., PRL’20

Cosmic High Energy Background Radiation

If Seyferts are neutrino sources,• Seyferts can simultaneously explain• TeV neutrino background(see also Begelman+’90; Stecker+’92;
Kalashev+’15; Murase+’20).

• X-ray background(e.g., Ueda+’03, Ueda+’14).

• MeV gamma-ray background(e.g., YI+’08, YI+’19, Murase+’20).

YI +’19

%. From the results of this work, we cannot comment
Another
Seyfertcandidate:NGC
4151
or all hard X-ray AGN in the catalog due to the flux
“2.9-sigma”
l neutrino flux from muon neutrino tracks.

• At ICRC 2023, IceCube reported

2.9-sigma detections of NGC 4151
and CGCG 420-015.

• NGC 4151 is the apparently brightest
Seyfert galaxy in X-ray band.

• But, have we seen any evidence of
non-thermal activity in Seyfert
galaxies?

2307.15349

Non-thermal Activity
in Seyfert Galaxies

Do we see non-thermal activities in Seyferts?

No, we haven’t! Thermal emission dominates everything.

Dust Disk

Corona+ Disk• If Seyferts are neutrino
sources,• we should see non-thermal
emission.

• BUT, thermal emission is
everything.

• Where is non-thermal
signature?

Hickox & Alexander+’16

1995ApJ...438..672M

Investigation of non-thermal activities in Seyferts

X-ray ? GeV ? MeV ?

OSSEIC 4329A
GINGA• Cascade or Synchrotron Self-

Compton for X-ray continuum(e.g., Kazanas & Ellison ’86;
Zdziarski ’86)

➡Neutrino emission (Stecker+’92)

ROSAT• But,• non-detection of power-law tailMadejski+’95(e.g., Madejski+’95; Lin+’93)

1995ApJ...438..672M

X-ray emission is from black hole corona

100 keV hot plasma above/below accretion disks

OSSE

IC 4329A• Power-law continuum isgenerated by• Thermal Comptonization of
disk photons in the corona.

GINGA
ROSAT

Madejski+’95©RicciDynamo action in disk:
Gravitational energy to B.

Magnetic loops

Coronal Synchrotron emission?

Magnetic loops emerge andMagnetized corona can generateSynreconnect
in emission
the corona.

• Hot corona ~ 100 keV

Disk

Magnetic energy is transferredtothermalenergy.
Heatedbymagnetic
activity
?
•

©
B.
Liu
reconnection(e.g., Haardt & Maraschi ’91; Liu, Mineshige, & Shibata ’02;
Beloborodov '17)

Evaporation of gas at disk surface.

-12

10

• Non-thermal electrons in corona?

-13

10

10-14

(Di Matteo+’97; YI & Doi ’14; Raginski & Laor ’16)

• Due to Synchrotron self-Absorption, we expect aspectral break at 10-1000 GHz (mm-wave).

10-15(c) B. Liu

2Compton scattering radiation.
• Millimeter Coronal Synchrotron Emission

νFν [erg/cm /s](YI, Totani, & Ueda ’08)

IC 4329A
B=103 G
2
B=10G
3
B=102 G w/ non-th
B=10 G w/ non-th
ALMA (60 sec)

-16

10

10-17
10-18
10-19
10-20
10-21 110102
Frequency [GHz]103

YI & Doi ‘14

Coronal Magnetic Activity
in Seyfert Galaxies

Do we understand all the activities in Seyferts?

Mostly yes. But, mm-wave is still an open and accessible window!

Dust

Disk

Corona+ Disk• millimeter-wave band is notwell investigated.

• Why? Because of dust???

• Dust emission would bemuch brighter than coronalsynchrotron signals.

Hickox & Alexander+’16

Table 1. Results of observations.
Obs. date

Array

(1)
1985 Jul 28
1990 May 23
2001 Sep 28
2003 Apr 03–May 25
2003 Jun 19
2003 Dec 24

(2)
VLA-C
VLA-D/AVLA-CnD
NMA-D
VLA-A
VLA-B

ν
(GHz)
(3)
22.5
22.5
22.5
95.7
8.46
43.3
22.5
14.9
8.46

Sν
(mJy)
(4)
< 5.0
< 3.3
1.9 ± 0.3
< 4.6
0.84 ± 0.08
2.0 ± 0.9
1.2 ± 0.3
0.81 ± 0.25
1.3 ± 0.1

σrms
(mJy beam−1 )
(5)
1.68
1.09
0.15
1.52
0.04
0.48
0.13
0.25
0.10

θmaj × θmin(arcsec×arcsec)(6)
1.5 × 1.1
5.6 × 3.9
3.8 × 1.7
8.1 × 6.1
0.35 × 0.25
0.35 × 0.14
0.56 × 0.31
0.88 × 0.44
1.7 × 0.8

Hints of millimeter excess in nearby Seyferts

φPA
(deg)
(7)
−20.0
59.0
72.3
−12.8
12.0
−30.2
−35.2
−39.3
−41.2

Col. (1) observation date; Col. (2) array configuration; Col. (3) center frequency; Col. (4) total flux density; Col. (5) image rms noise on blank sky; Cols. (6)–(7)synthesized beam sizes in major axis, minor axis, and position angle of major axis, respectively.

A new component in AGN SED? Non-thermal coronal Synchrotron?
10000

1435

BARVAINIS ET AL. : RADIO QUIET QUASARSNGC 985

1000
Flux density (mJy)

1435

100

10

1

0.1

10n

10

1

10

100
Frequency (GHz)

1000

10000

Doi & YI ‘16• Spectral excess in the mm-band

Fig. 1. Radio-to-FIR spectrum of NGC 985 nucleus. Open and Filled symbols are data published by other authors and data newly-presented in the present
study, respectively. Negative detections are indicated by downward arrows. Lines connecting symbols indicate quasi-simultaneous observations. Filled
Squares: our VLA observations with VLA-CnD at 22.5 GHz (AD456) and VLA-B at 8.46–43.3 GHz (AD489). Lower-peaked filled triangle: NMA
observation at 95.7 GHz as negative detection. Upper-peaked triangles: VLA-A observations; filled symbol at 4.89 GHz is data of Ulvestad & Wilson(1984) and reanalyzed in the present study; open symbol at 8.46 GHz is from archival data AN114. Open circles: VLA-C (AA48) and VLA-D/A hybrid(AB489, tapered to 100 kλ resulting in ∼ 4"" at all frequencies) observations by Barvainis et al. (1996); 22.5-GHz data (negative detections) are newly
reported in the present paper. Lower-peaked open triangle: NVSS result (Condon et al., 1998). Open diamonds: Herschel PACS at 70 µm and 160 µm
toward the nucleus (Meléndez et al., 2014). Open squares: IRAS Faint Source Catalogue, version 2.0 (Moshir & et al., 1990) at 60 µm and 100 µm. Solidand dashed curves: dust model spectra for cases of the emissivity β = 1 (33.7 K) and β = 2 (27.1 K), respectively.

(e.g., Antonucci & Barvainis’88; Barvainis+’96; Doi &Inoue ’16; Behar+’18).

Barvainis+’96• Contamination of extended components?
• Multi-frequency property?

12

Kawamuro et al.

ALMA observations toward nearby Seyferts
102

101

10

Fν [mJy]Fν [mJy]

ALMA
and Fermi observations of GRS 1734-292 0
1
IC 4329A

11

10

A Band 3, 4, and 6 VLA
flux in day-1 and VLA 15 GHz un-resolved flux as the input data,
10

0

ATCA
ALMA
Hybrid Corona
Jet
Total

10

-1

g result are shown in Figure 7. The estimated parameters are (S⌫SSA , ⌫SSA , fjet ) =+0.02
110+13
GHz,
0.26
60.02 ) assuming p = 2.7, where the errors are calculated based on the

10-1 01
2
10
1010d 84th percentiles of the posterior distributions.
Frequency [GHz]10-2 010

YI & Doi ‘18

NGC 985
VLA
ATCA
ALMA
Hybrid Corona
Jet
Total

101
Frequency [GHz]102

YI & Doi ‘18

Kawamuro+’22

Figure 12. Correlation of mm-wave and 14–150 keV luminosities, derived by using ALMA and BAT, respective
upper limits are shown as black circles. The black dashed line indicates the best-fit linear regression line, while tdenotes the ±1 scat range.

• Clear excess w/ PL tail in nearby Seyferts

We study the relations of the nuclear peak mm-wave
luminosity with representative AGN ones: 14–150 keV,
2–10 keV, 12 µm, and bolometric luminosities, and also
their flux relations. For quantitative discussions, we calculate the p-value (Pcor ) and the Pearson correlation coefficient (⇢P ) by using a bootstrap method (e.g., Ricci
et al. 2014; Gupta et al. 2021; Kawamuro et al. 2021).
This method draws many datasets from actual data,considering their uncertainties, and we derive the statistical values for each drawn dataset. For actual datawith upper and lower errors, we randomly draw values
from a Gaussian distribution where the mean and standard deviation are the best value and the 1 error, respectively. For data with only an upper limit, we use a
uniform distribution between zero and the upper limit.
For each draw, we also derive a regression line of theform log Y = ↵ ⇥ log X + , based on the ordinary leastsquares bisector regression fitting algorithm (Isobe et al.

1990). Moreover, an intrinsic scatter ( scat
the uncertainties in actual data, is derived
1000 datasets, we adopt the median value
bution for a parameter (i.e., Pcor , ⇢P , ↵,the best and their 16th and 84th percentil
and upper errors, respectively.
Figures 12 and 13 show the correlation
mm-wave luminosity for L14 150 , L2 10 ,Lbol . All are found to be significant asvery low p-values (Pcor ⌧ 0.01; Table B).
fluxes, significant correlations are confirm
supplementarily shown in Section B of theAmong the intrinsic scatters of the fity correlations, that for the 14–150 ke(0.36 dex) is the smallest compared to th
0.48 dex for L2 10 , 0.59 dex for LAGN
,12 µm ,for Lbol ). The smaller scatter compared(YI & Doi ’18; YI, Khangulyan, & Doi ’20; Kawamuro+’22; Michiyama, YI, +‘23)• Flux ~ 1-10 mJy peaking @ a few tens GHz• Time variability <4 days (Michiyama, YI+ submitted; Barnier, YI +in prep.)• Correlation b/w mm and X-ray luminosities (Kawamuro+’22, Ricci+’23)• Size : < 10 pc → Nucleus

Michiyama,
YI,+
submitted
magenta line indicates coronal emission (S⌫⇡ 1.5 mJy and ⌫SSA ⇡ 110 GHz in equation 2)
SSA

Structure of AGN core in the <10 pc scale

Where is the origin of the mm excess?

• Dust torus?
• spectral shape, not enough,variability• Free-free?
• spectral shape, not enough• Jet?
• radio-quiet, no blazar like activity• Corona
Ramos-Almeida & Ricci ‘17

cm-mm spectrum of AGN core

Power-law mm spectrum : Evidence of non-thermal coronal activity

Fν [mJy]

10

10• Hybrid (thermal + non-thermal) corona

2

ATCA

VLA

1

model

ALMA

IC 4329A
10

10

VLA
ATCA
ALMA
Hybrid Corona
Jet
Total

0

Corona-1

10

0

YI & Doi ‘18

1

10Frequency [GHz]10

2(YI & Doi ’14)

• Non-thermal electron fraction: 0.03 ( xed)
• Consistent with the MeV gamma-ray
background spectrum(YI, Totani, & Ueda ’08; YI+’19)• Non-thermal electron index: 2.9• Size: 40 rs

fifi• B- eld strength : 10 G

Acceleration & Cooling

Generation of non-thermal
electrons in coronae• Required CR injection index : ~2
• 1st-order Fermi acceleration would explain theobserved electrons• Other mechanisms may be di cult.

Electron Spectrum• Because of low magnetic eld.
• What is the acceleration mechanism?
• Time variability is a key to answer thisquestion.

ffi

fi• Note: more ALMA samples are needed.

YI + ‘19

High energy emission from AGN coronae

Multi-messenger Signature: MeV Gamma-ray & TeV Neutrinos• MeV emission

X-ray
MeV

• but, no GeV emission• Protons would be accelerated

γγ att.
Neutrino➡high energy neutrinos• Proton power is determined toreproduce the data

• See also Stecker+’91, ’92, ’05, ’13;

Kalashev+’15; Murase+’20; Gutiérrez
+’21; Kheirandish+’21

YI +’19

ALMA Observations toward the NGC 1068 Coremm excess is there• Based on our analysis(YI+’20; Michiyama, YI+2023.)• Corona Size: ~10-30 rs• Coronal B- eld: ~20-100 G• More ALMA data would be
Michiyama, YI, + 2023

necessary to clarify coronalproperty.

nent model assuming free-free emission/absorption described in Section 3.2.1. The black line is plotted based on Bayesianfi

The black dashed line indicates the free-free emission and absorption with parameters shown in Gallimore et al. (2004). (b) The

10°8∫ : Corona∞: Corona (Screen)

NGC 1068 in neutrinos

GRAMS(35 days)

E 2dN/dE [erg/cm2/s]

10°9∞: Corona (Uniform)
IceCube
4FGL
3FHL
MAGIC

10°10

10°11
AMEGO
(5 yrs)

10°12
GRAMS
(3 yrs)

10°13

10°14

10°15
106

107

108

109

1010

1011

1012

1013

1014

1015

1016

Energy [eV]YI, Khangulyan, & Doi, ’20• Type-2 Seyfert NGC 1068 is reported at 4.2-σ.
• If the signal is real, corona can be a plausible
neutrino production site

IceCube 2022

(Murase+’20; Kheirandish+’21; Anchordoqui+’22;

Eichmann+’22; Fang+’23; Hooper+’23; Ajello+’23).

How can we test the corona model?

ALMA? ngVLA? JEDI? COSI-X? GRAMS? AMEGO? IceCube-Gen2? KM3Net? XRISM?

mm-band102

10°8

Beam Size
100 mas10 mas
1 mas

ALMA (Our work)
VLBA
Archival Data

101

L. C. Gallo et al.

X-ray∫ : Corona∞: Corona (Screen)
GRAMS(35 days)

10°9

E 2dN/dE [erg/cm2/s]

F∫ [mJy]

Synchrotron, corona
Free-free, pc region
Total
ALMA

MeV & TeV ν

4∞: Corona (Uniform)
IceCube
4FGL
3FHL
MAGIC

10°10

10°11
AMEGO
(5 yrs)

10°12
GRAMS
(3 yrs)

10°13

10°14

100

101

102

Frequency [GHz]103

YI+’20• mm-excess• MeV spectral tail

10°15
106

107

108

109

1010

1011

1012

Energy [eV]

1013

1014

1015

YI+’201016

Gallo+’19

Figure 5. Left: The reflection spectrum from neutral material with solar abundancespredicted by different spallation models. The abundances from Skibo (1997, S97) are s
are shown as the blue, solid curve. Right: The reflection spectrum from ionised material
this work (Sect. 2). Note, that the adopted ionisaton model (XILLVER), currently does no
He- and H-like transitions are evident in the figure.

• TeV ν without GeV-TeV γtable differences in the spallation elements in question by adopting
Anders & Grevesse (1989).
One important caveat is that XILLVER includes only He- andH-like ions of the Fe-peak elements. Measuring or calculating theatomic data for the neutral stages of these elements is difficult andnot yet incorporated in XILLVER. The models presented here are
currently the best approximation of the ionisation scenario.
In Fig. 5 (right panel), the effects of spallation on ionised(⇠ = 100 erg cm s 1 ) material is shown. Several emission lines
from He- and H-like species of Ti, V, Cr, and Mn become signifi-• Nuclear spallation in X-ray

Finding Neutrino-Loud Seyferts?

A synergy among neutrinos, Hard X-ray, and mm is importantro et al.

• Dust torus attenuates Optical/X-ray emission.
➡ Hard X-ray survey (e.g., BAT catalog)

lessobscured• BUT, if Compton-thick, even hard X-ray can beabsorbed• Column density : NH > 1.5 × 10 cm
24heavily
obscured−2• NGC 1068 is a Compton-thick AGN• mm-wave (ALMA, ngVLA) will not be attenuated.
• BAT survey + follow-up by (ALMA + IceCube/KM3NeT/
TRIDENT?) is the best solution.

Figure 30.

Kawamuro+’22

Correlations between the mm-wave and 14–

Coronal Magnetic Field?

cm-mm spectrum of AGN core

Power-law mm spectrum : Evidence of non-thermal coronal activity

Fν [mJy]

10

10• Hybrid (thermal + non-thermal) corona

2

ATCA

VLA

1

model

ALMA

IC 4329A
10

10

VLA
ATCA
ALMA
Hybrid Corona
Jet
Total

0

Corona-1

10

0

YI & Doi ‘18

1

10Frequency [GHz]10

2(YI & Doi ’14)

• Non-thermal electron fraction: 0.03 ( xed)
• Consistent with the MeV gamma-ray
background spectrum(YI, Totani, & Ueda ’08; YI+’19)• Non-thermal electron index: 2.9• Size: 40 rs

fifi• B- eld strength : 10 G

How can we heat up corona?

Implication for the truncated accretion disk structure• Heating vs Cooling• Disk truncation at some radii (e.g. ~40 rs)2
Magnetic
Heating:
B
VA /4π•• QB, heat ~ 1010 erg/cm2/s
2ComptonCooling:
4kTn
σ
cU
l/m
c
•
e T
rad
e

• QIC, cool ~ 1013 erg/cm2/s• Magnetic eld energy is NOT su cient to

ffi

fl

fi

keep coronae hot.

• The inner part = hot accretion ow (Ichimaru’77, Narayan & Yi ’94, ’95).

• Heated by advection.
2/5
We
can
expect(YI+’19)
kT
∼
86
keV
(τ
/1.1)
•
e
T

• Suggested for Galactic X-ray binaries.

(e.g. Poutanen+’97; Kawabata+’10; Yamada+’13).

Plasma beta is too high? (too low magnetic field?)

Are weak-jet AGNs MAD or not MAD?

3094

J. C. McKinney, A. Tchekhovskoy and R. D.

• Our ALMA analysis suggests• coronal B- eld is ~10-30 G at 30 rs.
• In terms of plasma beta (β ≡ pgas /pmag),we have β ∼ 10 − 100.

• Gas pressure dominates the accretion dynamics.
• However, recent numerical simulations suggest β ≪ 1 for somecases
(e.g., McKinney+’12; Tchekhovskoy+’11; Liska+’23)fi• so-called magnetically arrested disk (MAD; Narayan’03)

McKinney et al. ‘12

We are observing AGNs without powerful jets

MAD is needed for powerful jet production

PoloidalToroidalLiska+’23• MAD is achieved when strong large-scale poloidal
magnetic eld exists.

• Otherwise, Parker instability would regulate
β ∼ 10 − 100 (e.g., Takasao+’18; Liska+’23)

fi

fi

fi

fi

Liska+’23• Coronal magnetic eld strongly depends on
initial magnetic eld con guration.

SMBH Spins and Dichotomy of AGNs

B of RL and RQ AGNs should be di

2 ·
2
2
2 2
erent because Pjet ≈ PBZ ∝ xa f(xa)ϕBH Minc ≈ a B

X-raying
Spin Distribution
Radio
Loudness Distribution
No. SMBH
2, 2007
RADIO LOUDNESS OF
AGNs
823

104

Reynolds+’21
Fig. 1.—Total 5 GHz luminosity vs. B-band nuclear luminosity. BLRGs aremarked by filled circles, radio-loud quasars by open circles, Seyfert galaxies,
and LINERs by crosses, FR I radio galaxies by open triangles, and PG quasars
by filled stars.

ff

ff• Same spins a for all AGNs

Accretion Rate

Sikora+’07
Fig. 3.—Radio loudness R vs. Eddington ratio k. BLRGs are marked byfilled circles, radio loud quasars by open circles, Seyfert galaxies and LINERs
by crosses, FR I radio galaxies by open triangles, and PG quasars by filled stars.

• ℛ di ers for 4 orders of magnitude
other feature revealed in Figure 3 is a clear change of slope of theSummary• Seyferts will be a dominant population in the neutrino sky• AGN corona would be a high-energy particle production
site• ALMA/X-ray + IceCube observations would be important• Are AGN corona in low-plasma beta? or high-plasma beta?

y
ic

e
n
nns
e
fit
d
e.
V
ueo
Xc],
y

ns
y
es

At the same time, a successful wind exceeding vesc canbe line-driven from the outer parts of the disk, mainly inthe equatorial direction that is shielded from ionization[10]. This outer wind can propagate farther and impact
the torus [37, 54], potentially inducing strong shocks andInteraction
betweenAccretion
Flows
and
Disk
Winds
DSA of protons [55], for which we assume a total proton[47] [71]. Approximating Lp ∼ Lp ln(Ep,max /Ep,min ), to42
power Lp,o . The
model
geometryisillustrated
inFig.1.
reproduce
Lν (ε
=
1
TeV)
∼
10
erg/s
as
observed,ν

AGN Failed Wind? (S. Inoue+’22)

4

µ

−1
Lp ∼ 8fpγ,net
Lνµ ln(106 ) ∼ 1044 erg/s, which is somewhat optimistic but within a plausible range, as discussed
above. With other parameters fixed, εν,max is plausibly
highest when "B = 0.5 and ηg = 1. Somewhat lower"B and/or higher ηg give lower εν,max that may be morecompatible with the current IceCube data [44].
The optical depth for γγ interactions with corona photons τγγ,cor (ε) " 410 (ε/1GeV) R̄1−1 [10], so gamma rays
co-produced with neutrinos are attenuated above a few
MeV, similar to the coronal region models.
For the outer torus region,
Ep,max,o∼−1
460 TeVηg,o(Bo /1 mG)(Ro /0.1 pc), imited by tdyn,o =Ro /vo " 6.2 × 108 s(Ro /0.1 pc). The pp gamma-ray luminosity per log ε is Lγ (ε) ≈ (1/3)2fpp,netLp (Ep = 10ε) [10]−1 −1−1where the net pp efficiency fpp,net = t−1
(t
+t
and
pp pp
dyn )
the pp loss timescale tpp " 1.6 × 109 s(no /106 cm−3 )−1[72]. Reproducing Lγ (ε = 1 GeV) ∼ 3 × 1040 erg/se.g.
Ro =+’22
0.1 pc,as observed [28] is feasible withS.
Inoue
FIG. 1. Schematicthe Lmodel.
The−1 accretion
6 diskno = sketch
106 cm−3of and
∼
3f
L
ln(10
) ∼
p
pp,net νµ−1around the black
drivesan outflowing
In2.5 × hole1042 (f(BH)
erg/s.
An ambient wind.
blackbodypp,net /0.5)

S. Inoue +’22

FIG. 2.
Model vs. observations of the multi-messenger
spectrum of NGC 1068 for fiducial parameters. Inner region:
R = 10Rs , vr = 1000 km/s, B = 510 G (!B = 0.1), ηg = 4,
Lp = 1044 erg/s. Outer region: Ro = 0.1 pc, no = 106 cm−3 ,Bo = 7 mG, Lp,o = 1.3 × 1042 erg/s. Total emission fromthe inner (red solid), outer (blue solid), and both (blacksolid) regions shown. Left: Electromagnetic spectrum. Components dominating each band highlighted: total pγ BetheHeitler (BeH) cascade (ochre dashed), external inverse Comp-• Two wind components may

explain both gamma-ray andneutrino data.

On the possible detection of NGC 4151

Corona model may be di cult to explain
3844

NGC 4151 Jettion of Right: NGC 4151 and Left: NGC 1068, showing the°11
ation of theposition obtained from the point source
10best-fit
he source as obtained from the catalog. The white Jet
unbrokenntour lines, respectively, around the sources computed using

Corona : ∫Fermi/LAT

Corona
Total

°12
10
nalysis with the highest significance are Seyfert galaxies

been reported in a previous IceCube study and hence,
he significance evaluation. NGC 4151 is observed at a

°13
10
find any evidence of significant neutrino emission from

Williams+’14

Figure 3. New full-resolution eMERLIN image of the central 4 × 2 arcsec2 (∼360 × 180 pc2 ) region of NGC 4151 using all seven eMERLIN antennas and anatural weighting. As in Fig. 1, the entire uv-range was used with a 0.15 × 0.15 arcsec2 FWHM restoring beam. Contours set are at −0.25, 0.75, 1, 1.5, 2, 3,
4, 5, 9, 16, 25, 36, 49 and 64 mJy beam−1 .

but the second analysis where we searched for emissionrces showing potential neutrino emission. Assuming theneutrino signal,°14we see that their spectra are softer with
10o the diﬀuse fluxes observed by IceCube with a spectral
rce class responsible for the bulk of the diﬀuse neutrino
e sources found in this analysis.

10°15 6
10

107

108

109

• Gamma-ray detected by Fermi (4FGL-DR2; Perretti+’23)

1010 1011 1012 1013 1014 1015

Energy E∞ (eV)YI & Khangulyan ‘23
ffi

ons of the Astronomical Society of the Pacific 107

flcentred on 1.51 GHz. The 512-MHz band was split into eight intermediate frequencies (IFs) of width 64 MHz and consisting of
128 channels in each IF. The calibrator NVSS J120922+411941(J1209+4119) was used for phase referencing, and OQ208 and3C286 were used as the band pass and flux calibrators, respectively.
The target and phase calibrator alternated during the observing run,with blocks of approximately 2.5 min on the phase calibrator and7 min on the target, with the flux and band pass calibrators observedat the end of the observing run.
To calibrate the data, we followed the procedure outlined in theeMERLIN cookbook (Belles et al. 2015), a summary of which we
include below. Correlation and averaging of the data was performed
before the SERPENT1 flagging code was used to remove the worst
instances of radio frequency interference (RFI) from the data. The
raw data were then inspected with the AIPS tasks SPFLG and IBLED to
remove any low-level RFI not picked up by the automatic flagger. In
addition to the RFI flagging, the first two IFs of the LL polarization
were flagged on all Lovell baselines due to the inclusion of a test
filter on the antenna. The channels showing no coherent phase at theends of each IF were also flagged. It is estimated that approximately
15 per cent of the on-source data was flagged during this process

2.1.1 eMERLIN Radio Imaging• Corona + Weak Jet model can explain the Fermi data

my and Astrophysics 53 no. 1, (2015) 365–408.

Rev. 25 no. 1, (2017) 2.

Downloaded from https://academic.oup.com/mnras/article/472/4/3842/4097195 by guest on 10 March 2023

Flux ∫F∫ (erg/cm2/s)

D. R. A. Williams et al.

These data were imaged with IMAGR, and phase self-calibration wasapplied to further refine the data before the visibilities were reweighted using REWAY to account for variable sensitivity as a function of antenna, as eMERLIN comprises of an inhomogeneous setof antenna types, frequency and time to maximize the resultant
sensitivity of the data. Further self-calibration improved the signalto-noise ratio (S/N), and the final image was created with the noisein the naturally weighted image of 35 µJy as shown in Fig. 3. Dueto the complex nature of this source and its brightness, great care
was taken to include only real features deemed to be genuine emission features in the self-calibration process. An amplitude and phaseself-calibration did not produce stable phases or amplitudes, so only
the final phase self-calibrated data are shown. This data set was thenused to create all further images of NGC 4151.

• But, the expected neutrino ux is an order ofmagnitude below the IceCube threshold• A nearby blazar exists (~1 deg away from NGC 4151)...
2.1.2 Archival MERLIN data reduction and imaging

Archival data originally published in M95 were re-reduced to com-

Now we live in the ALMA era.
• The Atacama Large Millimeter/submillimeter Array (ALMA) isan astronomical interferometer of 66 radio telescopes in
the Atacama Desert of northern Chile (from wikipedia).

• Covers millimeter and submillimeter bands.
• Has much higher sensitivity and higher resolution than before.

616

AJELLO ET AL.

Vol. 699

3

10

Nagoya balloon - Fukada et al. 1975
ASCA - Gendreau et al. 1995
SMM - Watanabe et al. 1997
COMPTEL - Weidenspointner et al. 2000
RXTE - Revnivtsev et al. 2003
Swift/BAT - Ajello et al. 2008
FSRQs, this work
BL Lacs, this work
Gilli et al. 2007

E2dN/dE [keV cm-2 s-1 sr -1]

Investigation of non-thermal activities in Seyferts

X-ray ? GeV ? MeV ?

102

10

• MeV background by hybrid corona in
102

Seyferts?

MeV background by
Seyferts(Γ,γ )=(3.8,4.4)

10-1(YI, Totani, & Ueda ‘08)tr=(3.8,4.0)
10-2
3
2
4
1
10
10
10
10
=(3.8,5.0)
Energy [keV]=(3.5,4.4) Figure 15. Spectrum of the CXB and contribution of the FSRQs (blue region). The data points are different measurements of the diffuse background as indicated in
FSRQs
can also explain the MeV background=(4.1,4.4) the label (Fukada et al. 1975; Gendreau
et al. 1995; Watanabe et al. 1997; Weidenspointner et al. 2000; Revnivtsev et al. 2003; Ajello et al. 2008b). The dashed line isthermal model the total contribution of Seyfert-like AGNs computed with the model of Gilli et al. (2007) arbitrarily multiplied by 1.1 to fit the CXB emission at 30 keV. The solidis the sum of the Seyfert-like and
FSRQs. The spectrum of FSRQs
been modeled
as a power-witha meanof 1.6. The blue region represents the(Ajello+’09,
buthassee
also
Toda,
YI,photon+ index‘21)
SMM line
range of values obtained from the Monte Carlo realizations of best-fit parameter ranges. The magenta solid line represents the contribution of BL Lac objects whose
HEAO-1 uncertainty is not plotted for clarity, but is, due to the low number of objects, >30% at any energy.
COMPTEL (A color version of this figure is available in the online journal.)•

MeV background by FSRQs

nonthermal

101

thermal100
102

YI, Totani, Ueda ’08

103
Photon Energy(keV)

Nagoya balloon - Fukada et al. 1975
ASCA - Gendreau et al. 1995
SMM - Watanabe et al. 1997
COMPTEL - Weidenspointner et al. 2000

102
E2dN/dE [keV cm-2 s-1 sr -1]

E2 dN/dE(keV2 cm-2 s-1 keV-1 sr-1)

1

104

RXTE - Revnivtsev et al. 2003
Swift/BAT - Ajello et al. 2008
FSRQs, this work
Gilli et al. 2007

10

1

10-1
1

10

102
Energy [keV]

3

10

104

Ajello+’09