Neutrinos and TeV photons from Soft Gamma Repeater giant

flares

Neutrino telescopes can be used as TeV detectors for short time scale events using s from

photoproduction in showers !Can AMANDA detect a signal from 27 Dec. giant flare

from SGR 1806-20 (above horizon)? In what channels?

• Review soft- and X-ray observations on SGR giant flares • A toy model based on Beppo-SAX SGR 1900-14 spectrum• Muon and Neutrino signals• Backgrounds• Useful information for the blind data analysis

Francis Halzen, Hagar Landsman, Teresa Montaruliastro-ph/0503348

LBL, IceCube Meeting, Mar. 2005

What are SGR’s?

• X-ray stars emitting short (~100 ms) bursts in X/soft -ray typically of energy 1041 D10

2 ergs

• Steady X-ray emission with luminosities 1035-1036 D10

2 erg/s with OTTB+power law spectra E-(13)

• From slow down rate of steady emission period (5-8 s) huge magnetic fields B ~1014-1015 G

• Similar to 8 Anomalous X-ray Pulsars but typically these do not emit bursts (1 exception)

• 5 galactic except for SGR 0526-66 in LMC

http://solomon.as.utexas.edu/magnetar.htmlWoods & Thompson, astro-ph/0406133

The Magnetar Model and emissionSteady X-ray emission powered by decay of n star magnetic field Luminosities 1035-1036 D10

2 erg/s periodic (5-8 s)

Neutrinos: Zhang et al ApJ 595 (2003)the potential drop through the magnetosphere of the rotating n star might accelerate protons above photomeson threshold (depends on n star period and B and geometrical factor) interaction on thermal radiation from heated n star surface

Rates strongly depend on beaming angle around polar axis

dN/dE E-2

Why giant flares?

•3 ‘giant’ flares: VERY HARD component dN/dE E-1.5-1.7 (Cheng et al., Nature 1996)

•Dec. 27, 2004 peak lasting 0.25 s followed by a 300 s long tail with 7.57 s

period and -140 s precursor (INTEGRAL, GCN2920) following previous series of bursts: Dec 21 and Oct 5. Still active.

Rearrangements of magnetic field and formation and dissipation of strong localized currents. These may fracture the rigid crust that outbursts

Can be a process in which nucleons and nuclei are accelerated

Similar to small GRB’s: SGR giant flares are 106-7 less intense but d2 1010

Detected radio afterglows imply relativistic outflows + huge luminosities with barion loading fireball (Piran et al, astro-ph0502148, Ioka et al, astro-ph/0503279)

Giant flare energy

Source SGR1900+14 (1998)

SGR1806-20 (2004)

Duration 0.35s 0.25 s

Fluence in initial pulse (ergs/cm2

)

>5.5·10-3 (Konus-Wind 15-250 keV)>6.4 10-4

(Beppo-SAX 40-700 keV)

2.4!!(GEOTAIL)>0.1 (RHESSI)Ge detectors up to 15 MeV saturated

No spectral measurement of the 1st s available. X-ray detectors suffered saturation effects. SGR 1900+14 AMANDA B-10

Beppo-SAX: Spectrum for first 68s up to 700keV (1s resolution)

SGR 1806-20 AMANDA-II (critical period) No spectrum available.

Similar flare. >2 orders of magnitude stronger

GEOTAIL (astro-ph/0502315) not saturated: measured fluence implies for d = 15 kpc a very efficient mechanism that releases ~1047 erg in 600 ms

The SGR 1900-14 Aug 27, 1998 giant outburstBeppo-Sax (Feroci et al, 1999)

A) 0-67 sec 70-650 keV OTTB+PL E-1 exp(-E/31.2 keV)+E-1.47

B) 68-195 sec 70-400 keV OTTB E-1 exp(-E/34.2 keV) + E-4.5

C) 196-323 sec 70-400 keVOTTB E-1 exp(-E/28.9 keV)

E-1.47

Guidorzi et al, 2004: response function of GRBM was not well known at large off-axis angles 70-600 keV only and 10% sys error

Spectrum Extrapolation at TeV energies

OTTB+PL fits

New best fit accounts better for the <60 keV region but for HE we use negative power law and vary it to account for the errors

Guidorzi private communication

Muons from Gammas Competition of pion interaction and decay in the atmosphere

(Drees Halzen Hikasa, PRD39, 1989, Stanev Gaisser Halzen PRD32 1985):

AMANDA-II horizontal averaged area = 30000 m2 and 0.3 s

At South Pole: =-20˚ = 70˚

spectra

Pion photoproduction cross section in FLUKA

XN

energy to produce of energy E

E,th = 10 GeV

Muon signal

But this particular flare was at 68˚ and Milagro analyses are commonly performed up to 45˚

astro-ph/01105131 Hz in 82 deg2 and 0.3 s at 5 km depth

0.86

Gamma showers in MILAGRO

For a source below horizon as SGR1900+14But also horizontal muonsfrom neutrinos but 1/ 2.65

Upward-going muons and cascades in AMANDA

Conclusions• We calculated possible muon and neutrino rates for Dec 27 giant

flare as a function of spectrum. AMANDA can constrain it !

• Relevant time scale of the order of 0.1 s and spatial constraint allow a search using downgoing muons

• We should use the neutrino cascade channel and look for neutrino induced muons

• We will preferably use IceTray or SIEGLINDE

• Start from raw data -> ROOT files