Neutrinos from galactic sources and the perspective for the coming - - PowerPoint PPT Presentation

Neutrinos from galactic sources and the perspective for the coming years

Viviana Niro

APC, Paris

Marseille, 18 December, 2019

based on VN, A. Neronov, L. Fusco, S. Gabici, D. Semikoz, arXiv:1910.09065 [astro-ph.HE]

• F. Halzen, A. Kheirandish, VN, arXiv:1609.03072 [astro-ph.HE]

M.C. Gonzalez-Garcia, F. Halzen, VN, arXiv:1310.7194 [astro-ph.HE]

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 1 / 25

Cosmic accelerators and neutrinos

There are different possible sources of cosmic rays, among which: Supernova remnant: considered the major source of galactic cosmic rays first suggested by Walter Baade and Fritz Zwicky in 1934 in 2013 the Fermi satellite has revealed γs from π0 decay for SNR IC443 and W44 → evidence for SNR as sources of cosmic-rays M. Ackermann et al., 1302.3307 [astro-ph.HE] Gamma ray bursts Active Galactic Nuclei Calculation of neutrinos expected at KM3 detectors from specific galactic sources of high-energy neutrinos ⇒ Milagro sources M.C. Gonzalez-Garcia, F. Halzen, V. Niro, arXiv:1310.7194 [astro-ph.HE];

• F. Halzen, A. Kheirandish, VN, arXiv:1609.03072 [astro-ph.HE]

⇒ Neutrinos from RX J1713.7-3946, Vela Junior, Milagro sources, Fermi Bubble

• F. Vissani, F. Aharonian, arXiv: 1112.3911 [astro-ph.HE], F. Vissani, F. Aharonian, N. Sahakyan, arXiv: 1101.4842 [astro-ph.HE]

⇒ Neutrinos from eHWC J1825-134 source

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 2 / 25

Flux of neutrinos and KM3 detectors

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• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 3 / 25

KM3 detectors

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 4 / 25

Diffuse flux at IceCube

From the data collected in 7.5 years of running of the IceCube detector, 60 events were identified with deposited energy Edep > 60 TeV.

IceCube Preliminary

• A. Schneider, arXiv:1907.11266 [astro-ph.HE], PoS-ICRC2019-1004

Moreover, at the moment a 3.5σ evidence is present for neutrino emission coming from the direction of the blazar TXS 0506+056

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 5 / 25

IceCube sensitivity to point-sources

−1.0 −0.5 0.0 0.5 1.0 sin(δ) 10−12 10−11 10−10 E2 · dN/dE [TeV cm−2 s−1]

dN/dE ∝ E−2

7yr Cascades 2yr Cascades 7yr Tracks ANTARES 2017

−1.0 −0.5 0.0 0.5 1.0 sin(δ) 10−13 10−12 10−11 10−10 E2 · (E/100 TeV) · dN/dE [TeV cm−2 s−1]

dN/dE ∝ E−3

7yr Cascades 2yr Cascades 7yr Tracks

−1.0 −0.5 0.0 0.5 1.0 sin(δ) 10−12 10−11 10−10 E2 · exp(E/Ecut) · dN/dE [TeV cm−2 s−1]

dN/dE ∝ E−2 · exp(−E/Ecut)

ANTARES 2017 (Ecut = 100TeV) 7yr Cascades (Ecut = 100TeV) 7yr Cascades (Ecut = 1PeV) 7yr Cascades (No cutoff)

Aartsen, M. G. et al., arXiv:1907.06714 [astro-ph.HE]

The IceCube detector has an optimal sensitivity for sources located in the northern hemisphere, and is less sensitive to sources located in the southern sky, using tracks events.

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 6 / 25

Sensitivity to point sources: E −2 spectrum

Letter of intent for KM3NeT 2.0, arXiv:1601.07459 [astro-ph.IM]

• V. Niro (APC, Paris)

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Sensitivity to point sources: E −2 spectrum

IceCube-Gen2: the next-generation neutrino observatory for the South Pole, PoS(ICRC2017)991

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 8 / 25

Sensitivity to point sources: spectrum with energy cut-off

• A. Albert et al., arXiv:1706.01857 [astro-ph.HE]
• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 9 / 25

A multi-messenger approach

A multi-messenger search is mandatory for the identification of the origin of cosmic neutrinos. Gamma-ray data are necessary to make correct estimation of neutrino fluxes from point-sources. The characteristic gamma-ray feature of a PeVatron include an hadronic, hard spectrum that extends until at least several tens of TeV. ⇒ a gamma-ray experiment with sensitivity to make detections up to about 100 TeV is of fundamental importance.

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Cherenkov Telescope versus Air Shower Array

Two complementary methods for gamma-ray air showers Cherenkov Telescope Air Shower Array Energy Threshold Low (< 200 GeV) High (> 10 TeV) Background Rejection Excellent (> 99.7%) Moderate (> 50%) Field of View Small (< 2◦) Large (> 45◦) Duty Cycle (uptime) Low (5% − 10%) High (> 90%)

http://www.hawc-observatory.org/science/detection.php

Imaging air Cherenkov telescopes: large upward-facing mirror to focus the Cherenkov light generated by the air shower. Air Shower Array: array of particle counters on the ground (plastic scintillators or tanks full of water).

• V. Niro (APC, Paris)

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Milagro sources

The highest energy survey of the Galactic plane has been performed by Milagro ⇒ bright sources in the nearby Cygnus star-forming region and in the inner part of the Galaxy

• A. Abdo PhD thesis; A. Abdo et al., arXiv:0705.0707, A. Abdo et al., arXiv:0904.1018;
• A. Abdo et al., arXiv:1202.0846, A.J. Smith, arXiv:1001.3695
• V. Niro (APC, Paris)

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HAWC results

In 2016, the HAWC experiment has confirmed four of the six sources: MGRO J1908+06, MGRO J1852+01, MGRO J2031+41, and MGRO J2019+37

A.U. Abeysekara et al., arXiv:1509.05401 [astro-ph.HE]; A. Sandoval, talk at Gamma2016 HAWC press release, April 18, 2016 April Meeting of the American Physics Society in Salt Lake City, Utah

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MGRO J1908+06

• 103

104 105 109 108 107 106 EΓGeV EΓ

2 dNΓdEΓs1 m2 TeV

MGRO J190806 ΑΓ2

HAWC HESS VERITAS ARGOYBJ 2012 Milagro ApJL

103 104 105 106 103 102 101 1 101 EΝ GeV Nevbinyr MGRO J190806 ΑΓ2 extended pointlike

Observed by HAWC with similar energy spectrum than VERITAS. cut-off energy: 30; 300; and 800 TeV.

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MGRO J1908+06

5 10 15 20 108 107 106 105 104 103 102 101 1 tyr pvalue MGRO J190806 ΑΓ2 3Σ 5Σ 1 2 5 10 20 50 100 108 107 106 105 104 103 102 101 1 EΝ

thTeV

pvalue MGRO J190806, extended ΑΓ2 t6 yrs 3Σ 5Σ

3σ discovery is possible in six years, if an energy threshold of about 5 TeV can be reached in the analysis, and that the spectrum extends to Ecut,γ of 800 TeV If Ecut,γ ∼ 300 TeV, expected for galactic sources able to explain the cosmic-ray spectrum up to the knee → an energy threshold of about 10 TeV would be required A 3σ discovery at a specific energy threshold will indicate a particular value of Ecut,γ

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 15 / 25

Confidence level limits

1.8 2.0 2.2 2.4 2.6 4.0 4.5 5.0 5.5 6.0 ΑΓ Log10Ecut,ΓGeV MGRO J190806

HESS t 15 yrs 95 99

MGRO J1908+06: IceCube is able to constrain a major part of the values for αγ reported by the HESS detector.

• V. Niro (APC, Paris)

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HAWC and IceCube results

Upper limit (90% C.L.) on the flux of high-energy muon neutrinos (black) for the stacking search of non-PWN sources in the 2HWC catalog. The projected muon neutrino fluxes (thin orange) represent the expected flux from each source. The combined flux (red) shows sum of the individual fluxes. A. Kheirandish, J. Wood, 1908.08546 [astro-ph.HE]

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eHWC sources

• A. U.Abeysekara et al., arXiv:1909.08609 [astro-ph.HE]

Nine sources are observed above 56 TeV, all of which are likely Galactic in origin

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 18 / 25

eHWC sources

• A. U.Abeysekara et al., arXiv:1909.08609 [astro-ph.HE]

eHWC J1825-134 source ⇒ Amongst the HAWC sources, it is the most luminous in the multi-TeV domain and therefore is one of the first that should be searched for with a neutrino telescope in the northern hemisphere

• V. Niro (APC, Paris)

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Fermi/LAT data

Fermi/LAT countmaps of the source region in 1-10, 100-300 and > 300 GeV energy ranges (left to right). The 1-10 GeV and 100-300 GeV maps are smoothed with 0.3 degree Gaussian, the 300 GeV map is smoothed with 0.5 degree Gaussian.

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 20 / 25

eHWC J1825-134 region

Spectrum of eHWC J1825-134 region measured by Fermi/LAT compared to the HAWC and HESS spectral measurements.

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 21 / 25

Neutrino flux

The neutrino fluxes at Earth can be described by: Nev = ǫθǫv t

• Eth

ν

dEν dNν(Eν) dEν × Aeff

ν ,

where a sum over neutrino and antineutrino contributions is implicit. ǫv = 0.57: visibility of the source, ǫθ = 0.72: takes into account a reduction factor due to the fact that only a fraction of the signal will be detected if the source morphology is assumed to be a Gaussian of standard deviation σext and the signal is extracted within a circular region of radius σeff = 1.6

• σ2

ext + σ2 res.

σres ∼ 0.1◦: angular resolution of KM3NeT/ARCA.

• V. Niro (APC, Paris)

Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 22 / 25

Effective area and source eHWC J1825-134

102 103 104 105 106 107 108 104 103 102 101 1 101 102 103 104 EΝ GeV Effective Area m2 KM3NeTARCA Effective Area at trigger level Effective Area trigger efficiency

103 104 105 106 103 102 101 1 101 102 EΝ GeV NΝEΝ yr1 eHWC J1825134 ΑΓ2.12

Right: Effective area used in the analysis (red solid line), effective area at trigger level (red dashed line), and trigger efficiency (blue dashed); Left: number of events expected for the atmospheric background (yellow area) and for the source for the best-fit value of αγ and different values of Ecut,γ.

Niro et al., 2019

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Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 23 / 25

eHWC J1825-134 source and extended region

103 104 105 108 107 106 105 104 103 102 101 1 EΝ

thGeV

pvalue eHWC J1825134

ΑΓ2.12; t10 yrs 3Σ 4Σ 5Σ

103 104 105 108 107 106 105 104 103 102 101 1 EΝ

thGeV

pvalue eHWC J1825134

HAWC Flux 1.5 ΑΓ2.12; t10 yrs Σ1.5º 3Σ 4Σ 5Σ

p-value for the best-fit value of αγ and different values of Ecut,γ for 10 years of running

• f the KM3NeT detector. The blue band represents the statistical errors in Ecut,γ.
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Galactic sources at neutrino telescopes Town Hall KM3NeT meeting 24 / 25

Conclusions

The BAIKAL-GVD detectorin Baikal Lake will have the discovery potential for this source similar to the KM3NeT detector KM3 detectors in water: better angular resolution of cascade events, which is about 2 degrees instead of about 10 degrees Combined analysis of different KM3 detectors could improve the sensitivity to this source The source MGRO J1908+06 was predicted to be one of the most promising source to be detected at the IceCube detector ⇒ Will eHWC J1825-134 be the first PeVatron source detected by the KM3NeT detector?

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