Search for GeV neutrinos associated with solar flares with IceCube - - PowerPoint PPT Presentation

Search for GeV neutrinos associated with solar flares with IceCube

Gwenhaël Gwenhaël de W de Wasseige asseige

for the IceCube Collaboration https://icecube.wisc.edu

I am about to tell you:

• How we can use the IceCube neutrino
• bservatory as a GeV neutrino detector
• Why solar flares are ideal candidates for this

event selec;on

2

Extracting GeV neutrinos

• Selec;ng neutrinos with E < 5GeV
• Searching for an enhancement in the event rate

during an astrophysical transient event

3

6

• Select the filters
• Remove HE events
• Try to remove noise

Extracting GeV neutrinos

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IceCube

DeepCore

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IceCube

Data Pure Noise Signal* 16 Hz 7 Hz 99.8 %

Extracting GeV neutrinos

• After filter selection

* = Neutrinos < 5GeV with E-2 spectrum

ü Select the filters

• Remove HE events
• Try to remove noise

Extracting GeV neutrinos

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What is the difference?

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How many Hard Local Coincidences ?

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Are they causally connected?

ü Select the filters

• Remove HE events

Extracting GeV neutrinos

NHLC-DOMS in IceCube strings ≤ 6 NHLC-DOMS in DeepCore strings ≤ 7 NDOMS causally connected ≤ 10

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Extracting GeV neutrinos

Data Pure Noise Signal 6.79 Hz 6.49 Hz 99.0 %

ü Select the filters ü After removing HE events

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U n c

• r

r e l a t e d t h e r m a l n

• i

s e C

• r

r e l a t e d s c i n t i l l a t i

• n

n

• i

s e Uncorrelated radioactive noise

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è Causality between hits

è (;me window, threshold, velocity)

U n c

• r

r e l a t e d t h e r m a l n

• i

s e C

• r

r e l a t e d s c i n t i l l a t i

• n

n

• i

s e Uncorrelated radioactive noise

ü Select the filters ü Remove HE events

• Try to remove noise

Extracting GeV neutrinos

Data Pure Noise Signal 0.22 Hz 0.11 Hz 57.0 %

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ü Select the filters ü Remove HE events ü Try to remove noise

Extracting GeV neutrinos

Data Pure Noise Signal 0.22 Hz 0.11 Hz 57.0 % Sensitive to SF!

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Solar flareν, what?

p,α… = Solar Energetic Particles

ν γ n

hadron acceleration

(up to several GeV)

π+è μ+ + νμ

μ+è e++νe+νμ

π0è2 γ π-è μ- + νμ μ-è e-+νe+νμ p + p¤ atmè

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Solar flareν, what?

p,α… = Solar Energetic Particles

ν γ n

hadron acceleration

(up to several GeV)

π+è μ+ + νμ

μ+è e++νe+νμ

π0è2 γ π-è μ- + νμ μ-è e-+νe+νμ p + p¤ atmè

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IceCube ν γ

F e r m i Sun

Solar flareν, how?

Solar flareν, how?

Fermi light curve for March 7th, 2012

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Solar flareν, how?

Fermi light curve for March 7th, 2012

20 minutes

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Solar flareν, why?

If detec;on: Confirmation of hadronic acceleration in solar flares If no detec;on: Strongest limit on Sfνflux In any case: Constraint on the proton acceleration

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htemp

Entries 341404 Mean 0.08654 Std Dev 0.1026

Neutrino energy (GeV)

0.5 1 1.5 2 2.5 3

yield per injected proton ν Average

7 −

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6 −

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5 −

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4 −

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3 −

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2 −

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htemp

Entries 341404 Mean 0.08654 Std Dev 0.1026

= 7GeV

max

E = 3GeV

max

E

Beam of protons: F(E) = A E-δ H(Emax – E) A and δ derived from observa;ons

Fixed δ= 3.2

Solar flareν, why?

Fixed δ= 3.2

• March 7th, 2012
• Impulsive phase
• 20 minutes
• 0.22Hz of data

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Take-home messages

• IceCube is sensi;ve to GeV neutrinos from

transient sources

• We can constrain solar flare physics

Thanks!

• Select the filters

Extracting GeV neutrinos

* AOF = Any Other Filter

AOF*

CascadeFilter MuonFilter VEF …

DeepCore Full Sky Starting Low-Up

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Extracting GeV neutrinos

è Causality between hits

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3 parameters:

• time window (ns)
• velocity (m/ns)
• threshold (#of pairs)

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• beam of protons of

F(E) = A E-δ H(Emax – E)

A and δ derived from observa;ons Geant4 simulation

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• beam of protons of

F(E) = A E-δ H(Emax – E)

A and δ derived from observa;ons

• Coupling with Fermi observa;ons: (δ, Emax)

Geant4 simulation

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