hadronic models for blazars and agn neutrinos martin pohl iowa state university

March 15, 2005XXXXth Rencontres de Moriond

Hadronic Models for Blazars

And AGN Neutrinos

Martin Pohl Iowa State University


D e c e m b e r 1 6 - 1 7 , 2 0 0 2V E R I T A S R e v i e w , W a s h i n g t o n D . C .

O v e r v i e w o f V E R I T A S S c i e n c e

A c t i v e G a l a c t i c N u c l e i *E x t r a g a l a c t i c B a c k g r o u n d L i g h t *

S h e l l - t y p e S u p e r n o v a R e m n a n t s

G a m m a - r a y P u l s a r s

P l e r i o n s

G a m m a R a y B u r s t s *

D a r k M a t t e r ( N e u t r a l i n o A n n i h i l a t i o n ) *

G a l a c t i c D i f f u s e E m i s s i o n

U n i d e n t i f i e d G a l a c t i c E G R E T S o u r c e s

L o r e n t z s y m m e t r y v i o l a t i o n

C o s m i c R a y O r i g i n Introduction I

Cygnus A

A blazar seen from the side







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C o s m i c R a y O r i g i n Introduction II

Low-energy component: synchrotron

High-energy component: leptonic or hadronic?







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C o s m i c R a y O r i g i n

Introduction III

What do models have to explain?

• high apparent luminosity

• emission up to > 10 TeV

• low-energy component cuts off at ~10 keV

• similar power in keV and TeV band

• system size R < D (1014 cm)







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Introduction IV

Hadronic models for blazars come in 3 classes:

• photo-hadron production

• proton synchrotron radiation

• proton-proton colliders

~1019 eV

~1012 eV







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C o s m i c R a y O r i g i n Basic Issues I

We need to store the particles!

RL << R => BG D >> 300 E19

Severe constraint for

photo-hadron production models

proton-synchrotron models







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C o s m i c R a y O r i g i n Basic Issues II

How many interaction partner are around?

Lobs ~ obs D3 c R2 nph >> obs D3 c RL2

nph

Electron spectrum: n()=n0 -2

Lsyn ~ (10-10 erg/s) D3.5 BG1.5 n0 EkeV

0.5 R3

nH > n0 > (1012 cm-3) L44 / D6.5 BG1.5

EkeV0.5







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Basic Issues III

How do we get rid of particles?

Energy losses?

p-models: t >> (105 sec) D2 nir E192 / L44 BG

2

p-sync-models: t ~ (1015 sec) / D BG2

pp-models: t ~ (106 sec) / D n9







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Basic Issues IV

The location of the X-ray synchrotron component

p-sync-models: must be primary e- !

p--models: first generation EkeV ~ 108 D BG

p-p-models: EkeV ~ 10-2 D BG Ep,TeV2







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C o s m i c R a y O r i g i n Models I

Model the jet

as

individual clouds

of

dense plasma

Beall & Bednarek; Dar & Shaviv;MP, Schlickeiser, (Vainio, Lerche)







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C o s m i c R a y O r i g i n Models II

In the jet frame:

isotropization andcompressionof interstellar particles

Colliding flows!







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C o s m i c R a y O r i g i n Models III

Two consequences:

• Enrichment with hadrons of energy ~

• Deceleration of the jet

• first half-cycle of relativistic shock acceleration

• similar to external shocks in GRBs, but without electron acceleration

Result:







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C o s m i c R a y O r i g i n Models IV

Radiation products

fully defined by

spectral evolution

of the particles

Reacceleration ?







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C o s m i c R a y O r i g i n Models V

Basic spectralform is reproduced

n~109

Homogeneousinterstellar medium

Variability from deceleration







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C o s m i c R a y O r i g i n Models VI

Inhomogeneousinterstellar medium

Rapid variabilityfrom interactionwith isolatedgas cloud







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C o s m i c R a y O r i g i n Neutrinos I

Expected

neutrino

intensity

Schuster, MP, Schlickeiser







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C o s m i c R a y O r i g i n Neutrinos II

Gamma-ray high state

F(> TeV)=10-10 cm-2 s-1

IceCube

=> 1 event/month

Muon localizationerror ~1.8deg

background 4 evts/month







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C o s m i c R a y O r i g i n Neutrinos III

Can the neutrino signal from AGN be higher?

Yes, if the gamma-ray spectrum extends to >> 10 TeV

• atmospheric background is reduced

• localization is better (~ 1 deg)

• But check the location of the synchrotron peak

The 2 AMANDA events associated with 1959+650are most likely background







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C o s m i c R a y O r i g i n Conclusions

• Three classes of hadronic AGN models exist

• p-p collision models appear best suited to explain -ray blazars

• p-p models prefer low-energy (TeV-ish) hadrons

• only TeV-ish neutrinos predicted

• neutrino event rate would be low

• p- models could produce HE neutrinos, but not TeV gamma-rays







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C o s m i c R a y O r i g i n Backup Slide

De-absorbed

spectrum of

Mrk 501

Based on

HEGRA dataPreliminary!

hadronic models for blazars and agn neutrinos martin pohl iowa state university

Documents

models iiin

models imodel

lercheveritas review

tev2veritas review

evtsmonthveritas review

sideveritas review

schlickeiserveritas

decelerationveritas