Neutrinos and TeV photons from Soft Gamma Repeater giant flares

1. Neutrinos and TeV photons from Soft Gamma Repeater giant flares Francis Halzen, Hagar Landsman, Teresa Montaruli astro-ph/0503348 Neutrino telescopes can be used as TeV g detectors for short time scale events using ms from p photoproduction in g showers ! Can AMANDA detect a signal from 27 Dec. giant flare from SGR 1806-20 (above horizon)? In what channels? • Review soft-g 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 LBL, IceCube Meeting, Mar. 2005

2. What are SGR’s? • X-ray stars emitting short (~100 ms) bursts in X/soft g-ray typically of energy 1041 D102 ergs • Steady X-ray emission with luminosities 1035-1036 D102 erg/s with OTTB+power law spectra E-(13) • 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.html Woods & Thompson, astro-ph/0406133

3. Steady X-ray emission powered by decay of n star magnetic field Luminosities 1035-1036 D102 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 The Magnetar Model and n emission dN/dE E-2 Rates strongly depend on beaming angle around polar axis

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

5. 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 Giant flare energy

6. The SGR 1900-14 Aug 27, 1998 giant outburst 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 keV OTTB E-1 exp(-E/28.9 keV) E-1.47 Beppo-Sax (Feroci et al, 1999) 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

7. 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 Spectrum Extrapolation at TeV energies OTTB+PL fits Guidorzi private communication

8. g spectra At South Pole: d =-20˚  q = 70˚ Muons from Gammas • energy to produce m of energy E Competition of pion interaction and decay in the atmosphere (Drees Halzen Hikasa, PRD39, 1989, Stanev Gaisser Halzen PRD32 1985): Pion photoproduction cross section in FLUKA Em,th = 10 GeV AMANDA-II horizontal averaged area = 30000 m2 and 0.3 s

9. 1 Hz in 82 deg2 and 0.3 s at 5 km depth 6 0.8 Muon signal astro-ph/0110513 Gamma showers in MILAGRO But this particular flare was at 68˚ and Milagro analyses are commonly performed up to 45˚

10. Upward-going muons and cascades in AMANDA For a source below horizon as SGR1900+14 But also horizontal muons from neutrinos but 1/ 2.65

11. 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