High Energy Astrophysics and Multi-messenger and IceCube

teresa.montaruli@unige.ch

Journée de réflexion du DPNC, Jun. 18, 2012

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Astrophysics from ground: middle size infrastructures

Middle-ground = 200M$ scale projects1 km^2IceCube 250 scientistsCTA 1000 scientists

} worldwide

CTA Vittorio’s talk

What is the physics addressed by IceCube?

Astrophysics

Particle Physics

CosmologyApplied Science

Neutrino sources (mqso, SNR, AGN,

GRBs, galactic plane)

Neutrino mass (oscillations)

Dark Matter South Pole climate

Cosmic ray anisotropies

(local sources, galactic

magnetic fields)

Neutrino x-section at UHE

GZK neutrinos Glaciology

Cosmic Ray composition at

transition between galactic/extragala

ctic

Violation of Lorentz Invariance

Earth density profile

SN explosion Monitoring Solar flare Monitoring

Sterile neutrinos & hierarchy with

low energy extensions

Paper in Nature 484, April 2012 (non observation of GRB events imples GRBs are not main sources of UHECRs or fireball needs to be revisited), 15 published in 2012 15 published papers in 2011, 13 published in 2010, 10 in 2009About 73 in total (including AMANDA)

IceCube

IceCube 59 (2009-10)

data analysis almost complete

EHE data analyzed and presented at Neutrino 2012

IceCube 79 (2010-11)

IceCube 59 (2009-10)

Point source unblinding by Juanan in a few daysIceCube 86 (2010-11)

Completed in January 2011 on schedule and with 6 more strings

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Upgoing and Downgoing neutrinosand backgrounds

Text

μν

Detection principle

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Why so large?

2 events / 672.7 days - background (atm. m + conventional atm. n) expectation 0.14 events preliminary p-value: 0.0094 (2.36σ)

To be able to see UHE events and reasonable statistics for low-luminosity beams

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How to reduce the large atmospheric neutrino and muon backgrounds?

2) Diffuse flux searches extect more events because they are integrated over the sky and can use energy but are subject to larger systematic errors

extra-galactic

galactic

Power-law spectra

≈E-2.7

≈E-3

≈E-3.2

≈E-2.7

Cosmic ray power isconnected to source power.

Cosmic ray composition is connected to source one.

They are key to understand: - acceleration of particles at the outmost power- highest energy phenomena where standard physics may break

At source: 1st Fermi acceleration in non-relativistic shocks / simulations of relativistic shocks in AGN jets:

Propagation effects in the Galaxy steepens to E-2.7

Further changes connected to change of sources.

Why also gammas and neutrinos?

‣Nature paper in Apr. 2012 demonstrated absence of neutrinos from gammas and limits severely constrain the GRB fireball model normalized to UHECRs or the GRBs are UHECR sources

‣The total source power is distributed between neutrinos and radio-to-γ-rays emission. We can normalize neutrino predictions to gamma total observed power.

‣Other UHECR possible sources: protons must be accelerated together with electrons in BH jets. μννννν

‣Protons will loose energy in pp and pγ interactions or synchrotron emission.

‣In principle the SED can fully be explained by IC in the high energy region of the photons up scattered by the synchrotron emitted photons at lower energies but there is is room for an hadronic component from μμνν

IC

MWL measurements

Cyg A

synchrotron

Multi-messenger astronomy- For π0 dominated: neutrinos and gamma-rays

spectrum are correlated. - For cascade dominated: total electromagnetic

power is needed to estimate the total neutrino flux.

excluded

Ethr = 1.2 GeV

always cascade dominated, additional parameter T of photon field

C. Tchernin, J.A. Aguilar, A. Neronov, T.M almost

submitted

Multimessenger and the unexpected in neutrino astronomy

neutrons escape => CRs & νs and gammas `Cocoon’: only neutrinos

confined protons attain sufficient Emax to produce UHECRs

neutrons escape before decaying

sufficient interactions to

produce neutrons & νs

Neutrinos prove matter acceleration in sources, keep their direction, probe their cores

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Atm

. m

uons

Point source 40+59 string resultsA

tm. neutr

inos

Hottest spot:ra: 75.45dec: - 18.15-log10(p-value) = 4.65nSrcbest = 18.3γbest= 3.9

observed value

74.2%

Point sources: E-2 median sensitivity and upper limits (90%cl)

Juanan’s new result to be unblinded in a whilea

while

Results for IceCube 40, Astrophys.J.732:18,2011 ANTARES,

arXiv:1108.0292

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Multi-messenger analysis adding time to reduce atmospheric backgrounds: flares

‣triggered search uses lightcurves from Fermi and gamma-ray telescopes‣untriggered gave 1% p-value

Hottest spot:ra: 21.25dec: -0.25-log10(p-value) = 6.69nSrcbest = 14.5σbest= 5.5 days

59 strings

AGN flares and sky scan: Astrophys.J. 744 (2012) 1 Crab flare: Astrophys.J. 745 (2012) 45 Microquasar periodic search: Astrophys.J. 748 (2012) 118

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Diffuse fluxes with νμ upgoingDirection and energy but larger systematicsCR composition knowledge at and above the knee matters

Limit is well below the upper bound on diffuse flux of neutrinos obtained normilizing the power of sources to observed UHECR spectrum

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Cosmological neutrinos: horiz. and downgoing

Models can be normalized on UHECR seen in Auger/HiReS and GeV diffuse flux in Fermi

79+86 strings 672.7 d

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Where do limits stand?

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Diffuse fluxes with cascades NC, ντ νeNo directionality but energy

Found 14 “cascade” events (11.6 bckg) after cuts in a total livetime of 373.6 days up to 175 TeV

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Why aren’t we yet seeing a clear evidence of astrophysical neutrinos?

Tom Gaisser’s interpratation

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The low energy frontier

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Initial Neutrino oscillation results

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Conclusions and future perspectives

- Data indicate that astrophysical neutrinos may be already popping up in our data in diffuse searches- Point sources need more time because of lower fluxes but limits are stringent indicating that probably the target mass where interactions occur is lower than expected- Diffuse fluxes need large excess because of systematics In the future low energy searches and UHE searches can be powered with new arrays (PINGU and ARA)- IceCube low energy extensions (DeepCore and PINGU) improve the already great potentials of IceCube for SN explosion monitoring and lightcurve detection adding potentials on energy reconstruction; for DM; for fundamental neutrino physics. PINGU/DeepCore have potential for sterile neutrino (given the many baselines/E) and for MH.DeepCore already convincingly demonstrates oscillations, with PINGU (30M$) will go into MH.

Infill of the IceCube DeepCorewith 20 strings (PINGU) to lower Eth to a few GeV

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MH discrimination: 10% variation of the relative atm muon neutrino rates (1 yr) for NI and NH in cosθzaccounting for energy and angular resolutions

➞Large significance can be achieved in 5 yr

Synergy with long baseline experiments that can confirm the result and also have the very important task of precision of parameter measurements and fundamental CP parameter(s) measurements.

Surprisingly large θ13 → possible measurement of

Mass Hierarchy by means of the atmospheric neutrino beam

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exclusion plots (Pγ)

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