april 23, 2009ps638 tom gaisser 1 neutrinos from agn & grb expectations for a km 3 detector

April 23, 2009 PS638Tom Gaisser

1

Neutrinos from AGN & GRB

Expectations for a km3 detector

April 23, 2009 PS638Tom Gaisser

2

Cosmic-ray factories?

Artist’s(*) conception of a massive, accreting, compact with accretion disk and relativistic jets

* Artist = Todor Stanev

April 23, 2009 PS638Tom Gaisser

3

Active Galaxies: JetsActive Galaxies: Jets

VLA image of Cygnus A

Radio Galaxy 3C296 (AUI, NRAO). --Jets extend beyond host galaxy.

Drawing of AGN core

M. Urry, astro-ph/0312545

April 23, 2009 PS638Tom Gaisser

4

Spectral Energy Distribution for blazars

Figure from Markus Bötcher, Astrophys. Space Sci 309 (2007) 95-104

April 23, 2009 PS638Tom Gaisser

5

- 10 seconds

fireball protons interact with remnant

of the star

0 seconds

fireball protons and

photons interact

afterwards

afterglow protons interact with inter-

stellar medium

TeV

PeV

EeV

Image: W. Zhang & S. WoosleySee astro-ph/0308389v2

Jet breakout in GRB following collapse of massive progenitor star

April 23, 2009 PS638Tom Gaisser

6Slide from Alexander Kappes

April 23, 2009 PS638Tom Gaisser

7

April 23, 2009 PS638Tom Gaisser

8

Energy content of extra-galactic component depends on location of

transition• Composition signature: transition back to protons

Uncertainties:• Normalization point:

1018 to 1019.5 usedFactor 10 / decade

• Spectral slope =2.3 for rel. shock =2.0 non-rel.

• Emin ~ mp (shock)2

April 23, 2009 PS638Tom Gaisser

9

Power needed for extragalactic cosmic rays assuming transition at 1019 eV

• Energy density in UHECR, CR ~ 2 x 10 erg/cm3

– Such an estimate requires extrapolation of UHECR to low energy CR = (4/c) E(E) dE = (4/c){E2(E)}E=1019eV x ln{Emax/Emin}

– This gives CR ~ 2 x 10 erg/cm3 for differential index = 2, (E) ~ E-2

• Power required ~ CR/1010 yr ~ 1.3 x 1037 erg/Mpc3/s– Estimates depend on cosmology and extragalactic magnetic fields:– 3 x 10-3 galaxies/Mpc3 5 x 1039 erg/s/Galaxy– 3 x 10-6 clusters/Mpc3 4 x 1042 erg/s/Galaxy Cluster– 10-7 AGN/Mpc3 1044 erg/s/AGN– ~1000 GRB/yr 3 x 1052 erg/GRB

• Assume E-2 spectrum. Then signal ~ 10 to 100/km2yr

– ~20% have E>50 TeV (greater than atmospheric background)

April 23, 2009 PS638Tom Gaisser

10

GRB model

• Assume E-2 spectrum at source, normalize @ 1019.5

• 1045 erg/Mpc3/yr• ~ 1053 erg/GRB• Evolution ~ star-formation rate• GZK losses included• Galactic extragalactic

transition ~ 1019 eV

Bahcall & Waxman, hep-ph/0206217Waxman, astro-ph/0210638

April 23, 2009 PS638Tom Gaisser

11

Berezinsky et al. AGN

• Assuming a cosmological distribution of sources with:– dN/dE ~ E-2, E < 1018 eV– dN/dE ~ E, 1018< E < 1021

– = 2.7 (no evolution)– = 2.5 (with evolution)

• Need L0 ~ 3 ×1046 erg/Mpc3 yr

• They interpret dip at 1019 as– p + 2.7p + e+ + e-

Berezinsky, Gazizov, Grigorieva astro-ph/0210095

April 23, 2009 PS638Tom Gaisser

12

Allard, Olinto, Parizot, astro-ph/0703633

Or start with a model of the extra-galactic component

Subtract it from the observed spectrum to get the galactic component

What is power needed for extra-galactic CR?

3 x 1017eV3 X 1018 eV

April 23, 2009 PS638Tom Gaisser

13

Model dependence of composition in galactic-extragalactic transition

Allard, Olinto, Parizot, astro-ph/0703633

proton model mixed model

• Model extragalactic component• Subtract from observed to get galactic component

April 23, 2009 PS638Tom Gaisser

14Heavies at end of galactic

Extra-galactic protons

Berezhko & Völk

arXiv:0704.1715v1 [astro-ph]

• Model galactic component• Subtract from observed to get extragalactic

Transition predicted:

1016.5 to 1017.5 eV

30

April 23, 2009 PS638Tom Gaisser

15

Detecting neutrinos

• Rate– Convolution of:

• Neutrino flux• Absorption in Earth• Neutrino cross section• Range of muon• Size of detector

Probability to detect-induced muon:

April 23, 2009 PS638Tom Gaisser

16

Neutrino effective area

• Rate:

= ∫(E)Aeff(E)dE

• Earth absorption– 10-100 TeV

• cos() > -0.8• Main effect near

vertical

– Higher energy ’s absorbed at larger angles

April 23, 2009 PS638Tom Gaisser

17

IceCube acceptance, resolution

Review of Particle Astrophysics Iowa State University, March 3, 2003

Thomas K. Gaisser18

Expected signals in km3

• Possible point sources:– Galactic

• SNR 0 - 10 events / yr• -quasars 0.1 - 5 / burst

~ 100 / yr, steady source• Magnetars ~ 30 events / yr

– Extra-galactic• AGN jets 0-100 / yr• GRB precursor (~100 s)

– ~ 1000 bursts / yr– ~ 0.2 events / burst

• GRB jet after breakout– smaller mean signal / burst

• Nearby bursts give larger signal in both cases

1800 / yr

20030

15

< 1

~ 1

charm

Diffuse (unresolved) sources--signature:• hard spectrum • charm background uncertain

April 23, 2009 PS638Tom Gaisser

19

Limits on excess of above atmospheric background

April 23, 2009 PS638Tom Gaisser

20Jim Braun, UW Madison, presented at Cosmo-08

Point source search with 7 years of AMANDA 3.8 yrs livetime 26 candidate sources

April 23, 2009 PS638Tom Gaisser

21

Search for neutrinos from GRB

Cascade(Trig & Roll)

Cascade(Rolling)

search

All flavor limits by AMANDAGRB models

Waxman-BahcallPRL 78 (1997) 2292

Murase-Nagataki APRD 73 (2006) 063002

Supranova,Razzaque et al.PRL 90 (2003) 241103

Choked burstsMeszaros-WaxmanPRL 87 (2001) 171102

Limits on neutrinos from GRB from AMANDA: -from cascades (e, ), Ap.J. 664 (2007) 397-from neutrino-induced muons, Ap.J (to be published)