# Presentation: 639803

## 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 Montaruli
- astro-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 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

## The Magnetar Model and  emission

- 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

- 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 outburst

- Beppo-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 keV
- OTTB 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 

- 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

- Pion photoproduction cross
- section in FLUKA

-  energy to produce 
- of energy E

- E,th = 10 GeV

**Notes:**
Vector dominance model

## Muon signal

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

*astro-ph/0110513*

- Gamma showers in MILAGRO

## 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

## 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