A new view of the universe withhigh-energy astrophysical neutrinos

International Center for Hadron AstroPhysics (ICEHAP), Chiba University
Aya IshiharaInterdisciplinary Science Conference in Okinawa (ISCO2023) at OIST Auditorium, 2 nd March 2023

Matter makes up everything in our daily life

protonneutronatom
𝑂𝑂(10-10m)

electron (-)

nucleus
𝑂𝑂(10-15m)

molecule~3 × 10−9 m

if an atom was scaled to a baseball fieldsize of a proton
atom
𝑂𝑂(10-10m)~1 mm
electron (-)~120m
nucleus
𝑂𝑂(10-15m)

if a PROTON was scaled to a baseball fieldsize of a NEUTRINO~1micron Lactic acid bacteria inyour intestine

proton𝑂𝑂(10-15m)~120m

Earth is neutrino brightBeta-decay
neutron

Production of geo neutrinos
protonelectronanti-electron
neutrinos
Energy of neutrinos~ MeVEarth is neutrino brightBeta-decay in nucleus

the original nucleus
neutronthe nucleus with larger atomic number

protonelectronanti-electron
neutrinos
in nucleus,
neutron + positron ⇔ proton + neutrino
proton + electron ⇔ neutron + neutrino
can also occur

Sun is neutrino bright
EarthSun

4p → He + 2e+ + 2νe + energy
protonpositronneutronEnergy of neutrinos~ MeV
distance to the object
0 km**Earth to the Galactic Center
28 kilo light years

Energy of neutrinos~ 10 MeV or lessdistance to the object
149.6 million km(0.00001581 light year)

neutrino

陽電子

Neutrino bright explosion!
EarthSupernova

Sun

Measured with Kamiokande, IMB,
Baksan in 1987

Kamiokande

SN1987aEnergy of neutrinos~ MeV
distance to the object
0 km**Earth to the Galactic Center
28 kilo light years

Energy of neutrinos~ 10 MeV or less

Energy of neutrinos~ 100 MeV or lessdistance to the object
149.6 million km(0.00001581 light years)

distance to the observed
object 160 kilo light years

Neutrino bright explosion
Supernova

νproton + electron→ neutron + neutrino

ν-confinement ν

Energy of neutrinos~ 100 MeV or lessνν1MeV-100MeV
Why we want to see the Universe with neutrinos?
1. to see the high-density states, such as the one formed in thesupernova explosion, and where light can not be escaped

100,000MeV – 10,000,000,000MeV
Why we want to see the Universe with neutrinos?
1. to see the high-density states, such as the one formed in thesupernova explosion, and where light can not be escapedfrom 100,000MeV=0.1 TeV
to 10,000,000,000MeV=10000 TeV

Somewhere in the Universe, ordinary matters (proton and nuclei) are accelerated to very high energy.
Particles beyond 108 TeV (1020 eV) observed

① high energy (1～108TeV) cosmic-rays (proton and nuclei) interact with matter (gas, plasma) andphoton field in the astrophysical objects

① high energy (1～108TeV) cosmic-rays (proton and nuclei) interact with matter (gas, plasma) andphoton field in the astrophysical objects
mesons (pions) are created(both charged and neutral)+

𝜋𝜋 , 𝜋𝜋0② a charged pion decays into muon and neutrino,a muon decays into positron and (anti) neutrinos+

𝜋𝜋 , 𝜋𝜋0charge neutral pions creates gamma-rays

neutrinos are born, so are gamma-rays,Correlation with the other emissions ofelectromagnetic waves; from radio to optical, x-ray,and gamma-ray
Mergers of big masses also emit gravitational waves

High energy neutrino is able to visualize the place where the high energy cosmicparticles are colliding

High energy neutrino is able to visualize the place where the high energy cosmicparticles are colliding

Active Galactic Nuclei(AGN)• 1012 times brighter than Sun

flow of high energy
cosmic particles

with jet and without jet0.1 TeV – 10,000 TeV
Why we want to see the Universe with neutrinos?
• to see the high-density states, such as the one formed in the supernova
explosion, and where light can not be escaped• to identify the region where the high energy cosmic-rays interact• to build models with gamma-ray + the other multi-messengers

0.1 TeV – 10,000 TeV
Why we want to see the Universe with neutrinos?
• to see the high-density states, such as the one formed in the supernova
explosion, and where light can not be escaped• to identify the region where the high energy cosmic-rays interact• to build models with gamma-ray + the other multi-messengers• to see the universe where light can not penetrate

CCD/CMOS 400-700nm
1.8-3.8eV• why and where in the Universe, light can not penetrate?

Martin Wolf, IceCube/NSF

CCD/CMOS 400-700nm
1.8-3.8eV

radio

infrared
opticalIR
optical
UV
X-rya

UV
Gamma-ray

radio

X-ray

gamma-ray

The Spectrum of the Universe (R. Hill et al 2018)
𝟒𝟒 × 𝟏𝟏𝟎𝟎−𝟔𝟔 𝟒𝟒 × 𝟏𝟏𝟎𝟎−𝟒𝟒 𝟎𝟎. 𝟎𝟎𝟎𝟎

𝟒𝟒𝟒𝟒𝟒𝟒𝟒𝟒 𝟒𝟒 × 𝟏𝟏𝟎𝟎𝟒𝟒 𝟒𝟒 × 𝟏𝟏𝟏𝟏𝟔𝟔 𝟒𝟒 × 𝟏𝟏𝟏𝟏𝟖𝟖 𝟒𝟒 × 𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏 [eV][Hz]radioMean free path in a photon density n1ℓ𝛾𝛾𝛾𝛾 ∼𝜎𝜎𝑇𝑇 𝑛𝑛IR
opticalUV
X-rya

Gamma-ray

CCD/CMOS 400-700nm
1.8-3.8eV

1Parsec(pc) = 3.26 light years

Tevatron, Pevatron, EeVatron, ZeVatronlog (attenuation length/Mpc)> TeV gamma-rays

near by AGNs

high energy photon

low energy photon− +near by galaxy𝛄𝛄𝛄𝛄 → 𝐞𝐞 𝐞𝐞radius of our galaxy

TeVPeVEeVZeV
Anchordoqui+
hep-ph/0206072v3

0.1 TeV – 10,000 TeV
Why we want to see the Universe with neutrinos?
• to see the high-density states, such as the one formed in the supernova
explosion, and where light can not be escaped• to identify the region where the high energy cosmic-rays interact• to build models with gamma-ray + the other multi-messengers• to see the universe where light can not penetrate• to use the universe as the elementary particle beam accelerator to explore
the particle physics beyond man made accelerators can no reach (notcovered)Measured cosmic neutrinos
with the IceCube neutrino telescopes in 10 years
where thetelescopes are

IceCube-170922A alert to worldwide telescopes

Science 361, eaat1378 (2018)• 2017/9/22 20:54:30.43 UTC• 5th and the most cosmic neutrino signal like EHE alert• automated alert was distributed to observers just 43 seconds later
Fermi Telescope

gamma-rays
neutrinosneutrino observed
optical light

Optical telescopes

Kanata telescope...and many more telescope

Magic telescope

Multi-messenger view of TXS 0506+056
upward going neutrino induced muontrack with energy 23.7±2.8 TeV loss
in the detector

HE gamma-ray observations• Fermi-LAT(20MeV - 300 GeV) reported gamma-ray flare

VHE gamma-ray observations• VHE gamma-ray Magic telescope (E >100GeV) with >6.2σ

Measured cosmic neutrinos
with the IceCube neutrino telescopes in 10 years
where thetelescopes areNGC1068 or M77

Very bright, well studied, spiral galaxy

18Mpc

𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈 𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔
𝟒𝟒. 𝟐𝟐𝟐𝟐𝛾𝛾 = 3.2 𝑎𝑎𝑎𝑎𝑎𝑎 𝑛𝑛� 𝑠𝑠 = 79+22−2032

Multi-messenger view of M77 (NGC1068)

Cosmic-particles interact near the core of AGN
obscuring gamma rays

Neutrino bright objects before 2018
Supernova

EarthSun

Energy of neutrinos Energy of neutrinos~ MeV~ 10 MeV or less

Energy of neutrinos~ 100 MeV or lessdistance to the object
0 km

distance to the observed
object 160 kilo light years

distance to the object
149.6 million km(0.00001581 light years)

Neutrino bright objects as of Today

Supernova

AGN
Seyfert Galaxy

SunAGNBlazar

Energy of neutrinos Energy of neutrinos~ MeV~ 10 MeV or less

Energy of neutrinos Energy of neutrinos~ 100 MeV or less ~ 100,000,000 MeV

Energy of neutrinos> 100,000 MeV

distance to the object
0 km

distance to the observed
object 160 kilo light years

distance to the observed
object 60,000,000 light years

Earthdistance to the object
149.6 million km(0.00001581 light years)

distance to the observed
object 4,000,000,000 light years

How the neutrino telescopes looks like?

How the neutrino telescopes looks like?
dark and transparent media

Cherenkov light

Charged particles
photonsensors

neutrinos

How the neutrino telescopes looks like?
measure the light(CCD/CMOS)

dark and transparent media
Convert neutrino to measurable light(lenses)

Cherenkov light

Charged particles
photonsensors

neutrinos

How the neutrino telescopes looks like?

High energy
neutrinos
arelight
Convert neutrino
to measureable(lenses)
rare to convert into light

Cherenkov light> 1km3Charged particles
photonsensors

neutrinosNeutrino Telescopes around the world
BAIKAL-GVD

Mediterranean Ocean
KM3NET ARCA (HE array)
as of Sept 2022, 21 ARCA
11 ORCA strings
2008-2022: ANTARES 0.1km3

Lake Bikal

South Pole
Glacial ice

IceCubeThe first km3-scale detector!
(full operation since 2011)

2022: Baikal-GVD
10++clusters, 288
x 8=2916 opticalmodules

IceCube
The first km3-scale detector!
(full operation since 2011)@ Amundsen-Scott
South Pole station

neutrino energy: 1TeV-10EeV

neutrino
neutrino
energy:energy:
1TeV-100EeV
5GeV-100GeV

Eyes: Light Sensor Module
Disk shaped computer
PMTEyes and lensLends: South Pole Glacial Ice

electronic
signal to thebrain

air temperature

ice thickness

Construction of IceCube

7yrs from the end of 2004 to the end of 2021

The first hole

125m

47

light we see in 0.01 sec
background event rate: 2730 Hz

signal event rate: 0.1/day ~ 10-6 Hz

First observation of the high energy cosmic neutrinos!

51neutrino sky beyond our galaxy

blazarbright seyfert spiralgalaxy54

We are in the early phase of the neutrino astronomy

with a tiny 1km3 telescope55

IceCube-Gen2: eight times more volume

Super-Kamiokande
41.4m in heightsky tree in Tokyo
634m

IceCube-Gen2: eight times more volume
to be installed in 2025

Super-Kamiokande
41.4m in heightsky tree in Tokyo
634m

10 times more number of sources

58• Universe is bright in neutrinos in high energy!
• Neutrinos connect the high energy particle production with theother form of radiations• Two sources:
1) evidence for neutrinos from flaring blazar TXS 0506+056
2) evidence for neutrinos from nearby Seyfert galaxy NGC1068• Neutrino sky is continued to be exciting and brighthttp://icecube.wisc.edu

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