Andrii NeronovAndrii Neronov

JEM-EUSOJEM-EUSO

Problem of the origin of cosmic rays

Galactic

Extragalactic?

Problem of the origin of cosmic rays

€

RL =ECRZeB

≈1Z −1 ECR1018eV

⎡ ⎣ ⎢

⎤ ⎦ ⎥B

10−6 G

⎡ ⎣ ⎢

⎤ ⎦ ⎥

−1

kpc

8 k

pc

Cosmic rays with energies below 1018 eV spread through the Galaxy in a diffusive way, scattering at magnetic field inhomogeneities.

Problem of the origin of cosmic rays

Deflected/randomized in the Solar system

Deflected/randomized by the Galactic magnetic fields

Cosmic ray "astronomy" window

F~3 UHECR/103 km2/yr

Existing statistics of UHECR events (~50 events) is not sufficient for identification of sources via clustering analysis.

Order-of-magnitude increase of statistics is needed for a sensible source search.

Search for the sources of UHECR

Pierre Auger Collab. '07

A=π(H tg(Θ/2))2≈(400 km)2

Extreme Universe Space Observatory at the Japanese Experiment Module (JEM-EUSO) of the International Space Station is a next-generation UHECR experiment, which will detect fluorescence light from UHECR induced air showers from space (400 km altitude) over Θ=60o field of view.

Wide FoV shower imaging telescope in space

http://www.nlsa.com/

All-sky exposure

Observation of UHECR events from the ISS has an advantage of homogeneous all-sky exposure, which is important for the statistical analysis of clustering pattern of UHECR events on the sky.

• Time of launch: FY2016-2017• Current status: JAXA: System Requirements Review (SRR) starts in May 2011;

ESA: included in the ELIPS/ISS program of ESA in 2010; NASA: APRA proposal, decision by Sept. 2012. RosCosmos: russian participation approved by STEC

committee end of 2011, now in the process of approval by the head of the

RosCosmos. • Operation Period: 3 years (+ 2 years)• Launching Rocket : H2B• Transportation to ISS: un-pressurized Carrier of H2 Transfer Vehicle (HTV)• Site to Attach: JEM Exposure Facility #2• Mass: 1983 kg• Power: 926 W 　 (operative), 352 W (non-operative)• Data Transfer Rate: 285 kpbs

Mission parameters

HTV launch September 11, 2009

The telescope

Fresnel lens system

Focal surface instrumentation: 2×105 pixels (MAPMT)+HV+trigger/readout electronics

4

Proton E=1020eV, =60º

UHECR data

Air fluorescence emission

Air-scattered Cherenkov emission

Cherenkov "ground-mark"

Clear sky

Low altitude Optically thick cloud

High altitude Sirrus cloud

UHECR data

Use of the atmosphere as cosmic ray detector requires precise knowledge of the state of the detector, i.e. knowledge of the real-time atmospheric conditions.

Clear sky

Low altitude Optically thick cloud

High altitude Sirrus cloud

UHECR data

Use of the atmosphere as cosmic ray detector requires precise knowledge of the state of the detector, i.e. knowledge of the real-time atmospheric conditions.

JEM-EUSO Atmospheric Monitoring System

Clear sky

Low altitude Optically thick cloud

High altitude Sirrus cloud

Use of the atmosphere as cosmic ray detector requires precise knowledge of the state of the detector, i.e. knowledge of the real-time atmospheric conditions.

JEM-EUSO Atmospheric Monitoring SystemSwiss / UniGE involvement in JEM-EUSO

Science Data Centre for the mission

Toward solution of the problem of the origin of UHECR

2012 2022

• +Exploratory objectives: Detection of UHE gamma-rays Detection of UHE neutrinos Study of Galactic and intergalactic magnetic field Verification of Relativity, search for Quantum Gravity effects Global observations of transient atmospheric phenomena: plasma discharges and lightning.

UHE neutrinos

UHE neutrinos produce deep-penetrating or up-going air showers readily distinguishable from UHECR showers.

JEM-EUSO measurements will either detect the "cosmogenic" neutrinos from UHECR interactions or constrain cosmological evolution of UHECR sources (cut-off energy, slope of z evolution).

Gorham et al. 2010

Berezinsky et al. 2010

UHE gamma-rays

JEM-EUSO will measure depth of the shower maximum Xmax with precision of 120 g/cm2 on event-by-event basis, sufficient to discriminate photons from nuclei.

Auger SDJEM-EUSO, ideal

JEM-EUSO, systematic

In the absence of systematics, non-detection of photon-like events puts an upper bound on the photon fraction at the level of ~10-3 at E~1020 eV.

Hooper et al. 2010

Systematic errors on Xmax reduce the sensitivity to photon fraction down to ~10-2 at 1020 eV, much better than the current Auger upper bound.

Detection of GZK photons within the lifetime of JEM-EUSO is possible.