Neutrino Astronomy in the Mediterranean: ANTARES Latest Results and Perspectives for Km3net/ARCA G

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Neutrino astronomy in the Mediterranean: ANTARES latest results and perspectives for KM3NeT/ARCA G. Ferrara INFN-LNS

30th Rencontres de Blois on “Particle Physics and Cosmology”, 3-8 Jun 2018 1 OUTLINE

• Multimessenger Astronomy and Neutrino Astronomy

• Astrophysical Neutrino detection principle

• Mediterranean Neutrino telescopes: - The ANTARES telescope, scientiﬁc goals and latest results - Status of KM3NeT/ARCA and future perspectives

• Conclusions and Outlook

2 Gamma-Rays, Neutrinos and Cosmic Rays

Astrophysical beam dump

Neutrinos smoking gun of hadronic process

3 Candidate High Energy neutrino sources in the Universe

Galactic: SNRs, Micro Quasars Extragalactic: AGNs, GRBs

ApJ 833 (2016) no.1, 3

Tension in the observed energy spectrum of astrophysical neutrinos ⇒ diffuse cosmic signal No neutrino source discovered 4 Why a neutrino telescope in the Mediterranean?

1) Location: 2) Medium: - Northern hemisphere - Deep Sea water: large volume of transparent medium - Complementary to IceCube -Very small light scattering (good angular resolution) - Milky-Way observation optimized - Natural backgrounds (40K and biolum) can be handled.

5 Astrophysical Neutrino detection principle

Shower-like Event: Poor angular resolution

ν Cherenkov photons γ

Track-like Event: reconstruction of muon trajectory Good angular resolution E > TeV

43°

neutrino νe muone µ

neutrino νμ Charge Current Interaction Measurement of time (ns), hit position (cm) and charge/ToT. νμ is the golden channel for astrophysical neutrino detection. 6 Astronomy with a Neutrino Telescope and Abyss environmental RESearch

Scientiﬁc goals: Search for TeV-PeV neutrino sources in the Universe. Dark Matter searches. Follow up of the Gravitational Waves event detected by A-LIGO.

ANTARES

Detector completed on May 2008. Largest Neutrino telescope in the Northern hemisphere at a depth of 2475 m. • 12 lines • 25 storeys per line • 350 m line height • ~ 70 m line distance 7 ANTARES Performances

Track event: Shower event: CC νμ NC νall , CC νe Golden channel Good energy reconstruction High angular accuracy Fair angular resolution

8 ANTARES Analyses and Main results

• Diffuse ﬂux and extended source search

• Search for point-like neutrino sources

• Time-correlated analysis with the HE IC muons and HESE

• Gravitational Waves

• Multimessenger astrophysics and transient fenomena

• Dark Matter and particle physics issues

9 ANTARES Diffuse ﬂux search

Study of the neutrino excess observed by IceCube ⇒ search for an all ﬂavor diffuse neutrino (ApJ 833 (2016) no.1, 3) signal with 9 years of ANTARES data

Data sample: • 2007-2015 (2450 days) Tracks • Tracks (CC νμ) and showers (NC νall + CC νe, ντ)

Event selection: • Tracks: θ >90°+ recons. quality parameters • Energy-based selection

Assumptions: Showers • Isotropic ﬂux • Equipartition among 3 ﬂavors • Single power law spectrum

10 ANTARES Diffuse ﬂux search

Study of the neutrino excess observed by IceCube ⇒ search for an all ﬂavor diffuse neutrino signal with 9 years of ANTARES data

Likelihood Fitting of the excess Unblinding: Events Tracks Showers Observed: 33 = 19 + 14 Expected: 24 = 13.5 + 10.5 Small excess in both samples

Best Fit (100 TeV): Φ(100 TeV) = (1.7±1.0) 10-18 [GeV cm2 s sr]-1 +0.5 Γ= 2.4 -0.4

1.6σ excess, null cosmic rejected at 85% CL 11 ANTARES point-like sources search

Galactic gamma rays sources in the Southern sky ⇒ Better pointing for a neutrino telescope in the Northern hemisphere Data Sample:

• 2007-2015 • 2424 days of live time • 7629 Tracks, 180 Showers

•

Analyses: • Full sky search: 1°×1° square over the ANTARES sky visibly

• Candidate search list: [Phys. Rev. D 96, 082001 (2017)] - 106 objects (pulsars, SNRs, …) - 13 IC HESE tracks

• Galactic Center Region: - extended region (ellipse) 15°× 20° - different test on spectral indices (Γ = 2.1, 2.3, 2.5) and source ext. (σ = 0°, 0.5°, 1°, 2°)

• Sagittarius A*: gaussian proﬁle with different widths (σ = 0°, 0.5°, 1°, 2°) 12 ANTARES point-like sources search [Phys. Rev. D 96, 082001 (2017)] Full sky search: 2423.6 equivalent livetime 7622 tracks + 180 showers

Maximum Likelihood search for clustering of neutrino events

Most signiﬁcant cluster (1.9σ) α = 343.80° δ = 23.50°

Sensitivities and upper limits at a 90% C.L. on the signal ﬂux from the Candidate list searches.

13 Search for time correlations between ANTARES neutrino candidates and IceCube HESE

Two of the neutrino events from the HESE sample occurred within 1 day of each other with a p-value of 1.6% ⇒ signature of a possible ﬂaring emission.

The ANTARES data-set is scanned to look for time and space correlation with 54 IceCube neutrino candidates.

IceCube event ⇒ potential transient neutrino source.

A maximum likelihood estimation to identify clusters of cosmic neutrinos over the background of randomly distributed atmospheric neutrinos.

No excess over the expected background is observed.

Upper limits at 90 % C.L. on the ﬂuence (orange triangles) and sensitivity (green dots) calculated for different time windows for two assumptions of the signal energy spectrum: S(E) = E −2.0 and S(E) = E −2.5. 14 Gravitational waves and neutrinos Coincident neutrino observation could constrain the source position • On 2017 August 17 A-LIGO and A-VIRGO detected the GW170817 • Fermi-GBM and INTEGRAL detected a short GRB, (170817A), from a consistent location • Optical observations allowed the precise localization of the merger in the galaxy NGC4993 • A joint multi-messenger follow-up search with ANTARES, ICECUBE and AUGER

• So far no coincidences with neutrino from the region of interest • Upper limit on the neutrino ﬂuence from each events over the whole spectrum

15 Multimessenger astrophysics and transient fenomena

• Effort of ANTARES to share data with other collaborations in the framework of the TAToO (Telescopes-ANTARES Target-of-Opportunity) program

• TAToO performs real-time reconstruction of muons ⇒ alert message generated to trigger robotic optical telescopes (TAROT, MASTER, ZADKO) [1] and radio telescopes (MWA) [2]. Subsample with higher energy generates an alert also to the Swift-XRT, the H.E.S.S. and the HAWC γ-ray detectors.

• 1 September 2015: ﬁrst telegram sent on behalf on the ANTARES Collaboration. XRT onboard Swift followed an ANTARES high-energy neutrino, detecting an uncatalogued X-ray source at 8 arcmin from the neutrino direction [3]. Low probability that the X-ray source is associated with the observed neutrino.

16 KM3NeT/ARCA: KM3NeT/ORCA see S. Hallmann contribution Km3 Neutrino Telescope for Astroparticle Reaserch with Cosmic in the Abyss

Scientiﬁc goal: discovery of TeV-PeV neutrino sources in the Universe.

KM3NeT

ARCA architecture:

• 2 blocks of 115 Detection Units (DUs), at a depth ~3500 m • ~ 90 m DU distance • 18 Digital Optical Modules (DOMs) for each DU • ~ 1 km3 volume • ~ 36 m DOM spacing • Time resolution ≈ ns • ~ 700 m DU height • Spatial resolution ≈ 10 cm • 1DOM equivalent to 3 ANTARES OMs 17 KM3NeT/ARCA Performances Shower event: Track event: NC νall , CC νe CC νμ Good energy reconstruction Golden channel Fair angular resolution High angular accuracy Angular resolution

Energy Reconstruction

18 KM3NeT/ARCA: status and preliminary results The ﬁrst 2 ARCA-DUs deployed on December 2015 and May 2016. Continuos data taking from December 2015 up to April 2017.

Local coincidences between PMTs allows for selecting Detector performances veriﬁed through the atmospheric muons over the optical background. measurement of the dependence of atmospheric muon ﬂux with the sea depth.

19 KM3NeT/ARCA sensitivities and future perspectives Point-sources analysis: - only up going track events - Hadronic scenario for the γ-rays production - Transparent sources - Expected neutrino ﬂuxes estimated from the observed γ-rays spectra following [4]

-11 -1 -1 -2 Φ0 = 10 [TeV s cm ] Preliminary plots 3σ Discovery potential Sensitivity

KM3NeT RXJ1713.7-3946 RXJ1713.7-3946

0 2 0 2 Galactic Centre Galactic Centre Φ Φ 1.8 1.8

/ Vela X / Vela X σ 90 3 1.6 Vela Jr 1.6 Vela Jr Φ Φ HESS J1614-518 (1) HESS J1614-518 (1) 1.4 1.4 HESS J1614-518 (2) HESS J1614-518 (2) 1.2 1.2 1 1 0.8 0.8 0.6 0.6 0.4 0.4 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 Observation time [year] Observation time [year]

20 KM3NeT/ARCA expectations (E-2 spectrum) KM3NeT/ARCA better sensitivity than IC in the Southern sky

KM3NeT/ARCA diffuse ﬂux

21 Conclusion and Outlook

• The ANTARES telescope has demonstrated the great potential of a deep-sea neutrino observatory in the Northern hemisphere

• KM3NeT/ARCA will be the largest neutrino telescope in the Mediterranean Sea able to monitor the Southern sky

- very good resolution and sky coverage - study of potential neutrino sources - conﬁrm IC ﬂux in few years - constrain/discover hadronic scenario in galactic gamma rays sources

KM3NeT/ARCA will offer a wide spectrum of further physics opportunities: - Multimessenger studies - Cosmic Ray Physics - Particle physics with atmospheric muons and neutrinos - Dark Matter

Thanks for the attention! 22 References

[1] S. Adrián-Martínez et al., JCAP 1602 (2016) 02, 062.

[2] S. Croft et al., Astrophys.J. 820 (2016) 2, L24.

[3] GCN circular n. 18231 and Atel telegram n. 7987.

[4] High-energy Neutrino follow-up search of Gravitational Wave Candidate G184098 with ANTARES and IceCube. The ANTARES and IceCube Collaboration, the LIGO Scientiﬁc Collaboration and Virgo Collaboration. Phys. Rev. D 93, 122010 (2016), http://arxiv.org/abs/ arXiv: 1602.05411

[5] F. Vissani, Astr. Phys. 26 (2006) 310

23 Spare slide

24 KM3NeT/ARCA basic detection element: Digital Optical Module

DOM: DU • 31 3” PMTs • All data to shore • Digital photon counting • Gbit/s on optical ﬁbre • Directional information • Hybrid White Rabbit • Wide acceptance angle • LED ﬂasher & hydrophone • Cost reduction • Tiltmeter/compass • 1DOM equivalent to 3 ANTARES OMs

~700m

Deployment Vehicle: • Rapid deployment • Unfurling by ROV • Multiple strings in one sea campaign

25 Multimessenger astrophysics and transient fenomena

• Effort of ANTARES to share data with other collaborations in the framework of the TAToO (Telescopes-ANTARES Target-of-Opportunity) program