Astrophysical Sources of Neutrinos and Expected Rates

Chuck Dermer U.S. Naval Research LaboratoryTeV Particle Astrophysics II

Madison, WisconsinAugust 28, 2006

Armen Atoyan U. de Montréal

Jeremy Holmes Florida Institute of Technology

Truong Le NRL

Nonthermal Neutrinos from Photohadronic Production

Mücke et al. 1999

SOPHIA code

Two-Step Function Approximation

MeVEb

MeVEMeVbE

r

rr

500,120

500200,340)(

Atoyan and Dermer 2003

MeVEbEK rrin 200,70ˆ)( (useful for energy-loss rate estimates)

Decay lifetime 900 n seconds

3

20

enn

pp

p

Neutron -decay

Flavor Changing

Threshold ’ m 140 MeV

42

2

ep

pp

- connection But without (buried sources)

without (leptonic emissions)

Nonthermal Neutrinos from Secondary Nuclear Production

e.g., Kelner, Aharonian, and Bugayov (PRD, 2006)

Dermer 1986Photon Targets (high radiation energy density and either VHE photons or particles)

vs. Particle Targets

(high target particle density but relatively low nonthermal particle energies)

Threshold Ep m 140 MeV

1. Isobaric production near threshold 2. Scaling representation at high energies

3

20

enn

pp

NNp

Rules out nuclear production in jet sources (Atoyan & Dermer 2003)

Implications of the Connection

“Best bet” Sources detection probability Gaisser, Halzen, Stanev 1995

Dermer & Atoyan NJP 2006

10)100/(1.0

,10)(

14

144

TeV

P

km-scale telescope (IceCube) has best detection probability near 100 TeV

Number of detected:

100 TeV

2424

14

2210

14

1010

/160

)(10)(

cmergscmergsN

ergs

cmergscmPN

N

Diffuse Rays and Point Sources of Rays as Candidate Sources

Diffuse Sources of Rays1. Diffuse Galactic Gamma Ray Background (Berezinsky et al. 1993)

2. Supernova Remnants3. Clusters of Galaxies 4. Diffuse Extragalactic Gamma Ray Background

Point Sources of Rays 1. EGRET point source catalog (~ 100 MeV – 5 GeV) (all sky)2. HESS point source catalog (> 300 GeV – several TeV)3. MILAGRO/all-sky water Cherenkov4. VERITAS/MAGIC in Northern Hemisphere5. GLAST: fall 2007

EGRET Detection Characteristics

Spark Chamber (vs. Silicon Tracker in GLAST)

Two-week detection threshold 1510-8 ph(>100 MeV) cm-2 s-1

(Dermer & Dingus 2004)

(high-latitude sources; background limited)

Hard spectrum (photon index s < 2)Energy range: ~100 MeV – 5 GeVThreshold energy flux: 10-10 ergs cm-2 s-1

Two week observation: ~106 secThreshold fluence: 10-4 ergs cm-2 s-1

Therefore examine which EGRET sources are bright and have hard spectra

Catalog of Established High Energy (> 100 MeV) Gamma-Ray Sources

Microquasars

GRBs

June 11, 1991

Kanbach et al. 1993

Flare Spectrum-ray spectrum fit by slow-decaying

(~255 minutes) pion emission and fast-decaying (~25 minutes) electron bremsstrahlung

Energy flux at 100 MeV: ~ 10-8 ergs cm-2 s-1

Energy fluence at 100 MeV: ~ 210-4 ergs cm-2

Butvery soft spectrums > 3 – 4

Solar -Ray Flares

Measured Integral Flux: = 19 10-8 ph(>100 MeV) cm-2 s-1

(Sreekumar et al. 1992)“resulting spectral shape consistent

with that expected from cosmic ray interactions with matter”

Third EGRET catalog (Hartman et al. 1999)

= 14.4(±4.7) 10-8 ph(>100 MeV)

cm-2 s-1

s = 2.2(±0.2)

F = 2.3 10-11 (E/100 MeV)-0.2 ergs cm-2 s-1

>> 2 yrs to detect neutrinos from the LMC

Large Magellanic Cloud

Brightest persistent -ray sources F 10-3 MeV cm-2 s-1 10-6 GeV cm-2 s-1 10-9 ergs cm-2 s-1

Therefore require only >> 105 s ~ 1 day to reach F >> 10-4 ergs cm-2 s-1

But…spectra drop off steeply above 1 – 10 GeV (pulsar), 100 MeV (nebula)

Thompson 2001

Vela pulsar

Pulsed component consistent with electromagnetic cascade radiation in polar cap or outer gap

Nebular component consistent with synchrotron + SSC component from cold MHD wind

de Jager et al. 1999

Crab nebula

Pulsars

Microquasars: VHE -Ray Detection of LS 5039

Aharonian et al. (2005)

Confirms ID of Paredes et al. (2000)

Cui et al. (2005)Mean orbital separation d 2.51012 cm (0.2 AU)

Companion Mass 23 Mo (Casares et al. 2005)

• HESS Detection of LS 5039 at 200 GeV – 10 TeV

• Consistent with point source (< 50)

Multiwavelength Spectrum of LS 5039

Aharonian et al. (2005)

F flux = 10-12 ergs cm-2 s-1 assumed to extrapolate to 100 TeV with s = 2 spectrum requires >>108 sec 3 years to reach fluence level of >> 10-4 ergs cm-2 s-1 (assuming hadronic emission; cf. Dermer and Böttcher 2006)

Generic problem for detecting sources with F flux << 10-11 ergs cm-2 s-1

XMMXMM

RXTERXTE

1 TeV

Geminga-like pulsars

Pulsar wind nebulae

Dark dust complexes irradiated by cosmic rays

Grenier et al. (2005)

Low-mass microquasars

Background AGNs

Clusters of Galaxies

EGRET Unidentified Sources

Clusters of Galaxies

F few10-13 ergs cm-2 s-1 at 1 TeV

Implies >> years required to detect with a km-scale telescope

Berrington and Dermer (2005)

Inte

gral

pho

ton

flux

ph(

>E

cm

-2 s

-1)

3C 296

Radio Galaxies and Blazars

3C 279, z = 0.538

L ~1045 x (f/10-10 ergs cm-2 s-1) ergs s-1

Mrk 421, z = 0.031

Cygnus A

L ~5x1048 x (f/10-9 ergs cm-2 s-1) ergs s-1

FR2/FSRQ

FR1/BL Lac

Possible photon targets for p +:• Internal: synchrotron radiation

(Mannheim & Biermann 1992, Mannheim 1993, etc.)

requires a compact jet: nphot

() Lsyn

/ Rjet

2

target disappears with jet expansion on:

t ' ~ R'jet

/c ~ tvar/(1+z)

• External: accretion disk radiation (UV)

(i) direct ADR: (Bednarek & Protheroe 1999)

anisotropic, effective up to

R < 100 Rgrav

< 0.01 pc

(ii) ADR scattered in the Broad-Line region (Atoyan & Dermer 2001)

quasi-isotropic, up to RBLR

~ 0.1-1 pc

Impact of the external ADR component: available on yrs scale (independent of L) high p-rates & lower threshold energies:

protMeV/(1- cos)

Photo-hadronic jet models

=7 (solid)

=10 (dashed)

=15 (dot-dashed)

(red - without ADR)

(for 1996 flare of 3C 279)

(3C 279)

solid- neutrons escaping from the blob, and dashed- neutrons escaping from BL region (ext. UV)

dot-dashed- rays escaping external UV filed (produced by neutrons outside the blob) dotted- CRs injected during the flare, and 3dot-dashed- remaining in the blob at l = RBLR

● Total energetics in UHE particles ( for parameters of the Feb 96 flare) =10 : W

CR(>1 PeV)

= 6 1051 erg, W

n / W

CR = 3.3%, W /WCR

= 4.4%

=15 : WCR

(>1 PeV) = 3.1 1051 erg, W

n / W

CR = 8.9 %, W /WCR

= 0.9% ● Particle energies in the neutral beam

E ~ 1PeV- 3 EeV , En ~ 10PeV - 30 EeV

Neutron & -ray energy spectra & beam power

Powerful FSRQ blazars / FR-II Radio Galaxies ● Neutrons with E

n > 100 PeV and rays with E > 1PeV

take away ~ 5-10 % of the total WCR

(E > 1015eV=1 PeV) injected at R<RBLR

Neutron &- ray beams in BL Lacs/FR-I

'Mkn 501'

Blue solid- neutrons escaping from the blob and external field, 3dot-dashed- neutrinos

dot-dashed- rays escaping external filed dotted- protons injected during the flare, and thin solid - protons remaining at l = RBLR

● UHE neutral beam energetics (stationary frame): =10 : W

CR(>1 PeV)

= 5.2 1048 erg, W

n / W

CR = 3.3 10- 4 , W /WCR

= 4.3 10 - 7

=25 : WCR

(>1 PeV) = 5.3 1047 erg, W

n / W

CR = 4.5 10- 4, W /WCR

= 1.6 10- 4

● Particle energies in the neutral beam E < 1 EeV , E

n ~ 30PeV - 5 EeV

neutrons with En > 100 PeV and rays with E > 1PeV

take away << 0.1 % of the total injected WCR

(E > 1 PeV)

Neutrinos: expected fluences/numbers

Expected - fluences calculated for 2 flares, in 3C 279 and Mkn 501, assuming proton aceleration rate Qprot(acc) = Lrad(obs) ; red curves - contribution due to internal photons, green curves - external component (Atoyan & Dermer 2003) . Expected numbers of for IceCube - scale detectors, per flare:● 3C 279: N = 0.35 for = 6 (solid curve) and N = 0.18 for = 6 (dashed) Mkn501: N = 1.2 10-5 for = 10 (solid) and N = 10-5 for = 25 (dashed) (`persistent') -level of 3C279 ~ 0.1 F (flare) , ( + external UV for p )

N ~ few- several per year can be expected from poweful HE FSRQ blazars. N.B. : all neutrinos are expected at E>> 10 TeV

UHE neutrons & -rays: energy & momentum transport from AGN core

UHE -ray pathlengths in CMBR:

l ~ 10 kpc - 1Mpc

for the predicted E~ 1016 - 1019 eV

• neutron decay pathlength:

ld (

n) =

0 c

n , (

0 ~ 900 s)

ld ~ 1 kpc - 1Mpc

for the predicted E~ 1017 - 1020 eV • High redshift jets: photomeson processes on neutrons turn on

• a new interpretation for large-scale jets ? (!) ( ??? )

solid: z = 0 dashed: z = 0.5

d ~ 200 Mpc

l jet

~ 1 Mpc (lproj

= 240 kpc)

L

X(jet) = 1.4 1041 erg/s

L

X(h.spot) = 1.7 1042 erg/s

x ~ 1.1,

radio ~ 0.8

S(syn.lobes) ~ 10-11 erg/cm2 s

Pictor A in X-rays and radio (Wilson et al, 2001 ApJ 547)

Pictor A

Fluence distribution of 2135 BATSE GRBs

Fluence Distribution of GRBs

McCullough (2001)

104

21

1

6.0

)(

A

APd

N

Detection of neutrinos requiresGRBs at fluence levels > 3x10-4 ergs/cm2 (2-5 GRBs per year at this level) unless GRBs are hadronically dominated

Photon and Neutrino Fluence during Prompt Phase

Hard -ray emission component from hadronic-induced electromagnetic cascade radiation inside GRB blast wave Second component from outflowing high-energy neutral beam of neutrons, -rays, and neutrinos

e

pnep

2

),,(0

Nonthermal Baryon

Loading Factor fb = 1

tot = 310-4 ergs cm-2

= 100

Evidence for Anomalous -ray Emission Components in GRBs

Long (>90 min) -ray emission

(Hurley et al. 1994)

GRB 940217GRB 940217

Nonthermal processes

Two components seen in two epochs

MeV synchrotron and GeV/TeV SSC

lower limit to the bulk Lorentz factor of the outflow

How to explain the two components?

Two components seen in two separate epochs

How to explain the two components?

Anomalous High-Energy Emission Components in GRBs

Evidence for Second Component from BATSE/TASC Analysis

Hard (-1 photon spectral index) spectrum during

delayed phase

−18 s – 14 s

14 s – 47 s

47 s – 80 s

80 s – 113 s

113 s – 211 s

100 MeV

1 MeV

(González et al. 2003)

GRB 941017

Second Gamma-ray Component in GRBs: Other Evidence

(Requires low-redshift GRB to avoid attenuation by diffuse IR background)

Delayed high-energy -ray emission from superbowl burst

Seven GRBs detected with EGRET either during prompt MeV burst emission or after MeV emission has decayed away (Dingus et al. 1998)

Average spectrum of 4 GRBs detected over 200 s time interval from start of BATSE emission with photon index 1.95(0.25) (> 30 MeV)

Atkins et al. 2002Bromm & Schaefer 1999

O’Brien et al. (2006)

Swift Observations of Rapid X-Ray Temporal Decays

Tagliaferri et al. (2005)

Rates for 1020 eV Protons with Equipartition Parameters

Standard blast wave model with external density = 1000 cm-3, z = 1

Within the available time, photopion losses and escape cause a discharge of the proton energy several hundred seconds after GRB

Rapid blast wave deceleration from radiative discharge causes rapid X-ray declines

10-5

10-4

10-3

10-2

1 10 100 1000

Observer time t(s)

Com

ovi

n R

ate

s (s

-1)

racc 1/t'

ava

r

rp,syn

resc

Calculated at Ep=1020 eV

Dermer 2006

Neutrinos from GRBs in the Collapsar Model

(~2/yr)

Nonthermal Baryon Loading Factor fb = 20

Dermer & Atoyan 2003

requires Large Baryon-Loading

Gamma-Ray Bursts as Sources of High-Energy Cosmic Rays

Solution to Problem of the Origin of Ultra-High Energy Cosmic Rays

(Wick, Dermer, and Atoyan 2004)

(Waxman 1995, Vietri 1995, Dermer 2002)

Hypothesis requires that GRBs can accelerate cosmic rays to energies > 1020 eV

Injection rate density determined by GRB formation rate (= SFR?)

GZK cutoff from photopion processes with CMBR

Ankle formed by [air production effects

(Berezinsky and Grigoreva 1988,Berezinsky, Gazizov, and Grigoreva 2005)

Star Formation Rate: Astronomy Input

Hopkins & Beacom 2006

USFR

LSFRHB06

SFR6,pre-Swift

Le & Dermer 2006

SFR6,Swift

SFR6,pre-Swift

Fitting Redshift and Opening-Angle Distribution

UHECR Spectra for Different SFRs

Provides good fits to HiRes data with fCR 50 - 70

Waiting for next data release of Auger

fCR 50

GZK neutrinos from UHECRs produced by GRBs

Assume GRBs inject power-law distribution with exponentional cutoff energy = 1020 eV with rate density different SFR histories

Dermer & Holmes 2006

fCR = 50

AMANDARICE

Halzen & Hooper 2006

Summary

- Connection -ray fluence (extrapolated to 100 TeV) > 10-4 ergs cm-2 required for detection for optically thin sources

Best bet for detectable neutrino point source with km-scale detector (IceCube): v from photohadronic processes

Blazar AGNs (FSRQs, not BL Lacs)

Surrounding target radiation field; 1 PeV neutrinoGRBs Signatures of hadronic acceleration in GRBsMicroquasars (?) probably too weak

Best bet for detectable diffuse neutrino sources:GZK neutrinos from cosmological sources of UHECRs (GRBs)Cosmic-ray induced galactic diffuse emission

Lots of room for surprises…