1

UHECRs from Black-Hole Jet Sources

Chuck DermerSpace Science Division

US Naval Research Laboratory, Washington, DC charles.dermer@nrl.navy.mil

"Searching for the Origins of Cosmic Rays"

Trondheim, Norway, June 15-18, 2009

Happy Birthday, Venya!

2

Black-Hole Jet Sources of UHECRs

Nonthermal rays relativistic particles + intense photon fields

Leptonic jet model: radio/optical/ X-rays: nonthermal lepton synchrotron radiation

Hadronic jet model: Photomeson productionsecond -ray component

p → → , , nNeutrons escape to decay and become UHECR protons (Neutral beam model: Atoyan & Dermer 2003)

Large Doppler factors required for -rays to escape

Photohadronic vs. ion synchrotron models

3

Outline

Requirements for UHECR sources:– Extragalactic (but within the GZK radius)– Emissivity (>1044 erg Mpc-3 yr-1)– Power (> 1046 erg s-1) (for Fermi acceleration)

Extragalactic Gamma Ray Sources from Fermi Radio Galaxies and Blazars as Sources of the UHECRs Gamma-Ray Bursts as Sources of the UHECRs

Dermer, Razzaque, Finke, Atoyan (New Journal of Physics, 2009)Razzaque, Dermer, Finke (Nature Physics, submitted, 2009)Dermer and Menon, “High Energy Radiation from Black Holes: Gamma Rays,

Cosmic Rays, and Neutrinos” (Princeton University Press, 2009)

4

GZK Horizon Distance for Protons

Horizon distance vs. MFP: Linear distance whereproton with measured energy E had energy eE

For model-dependent definition:Harari, Mollerach, and Roulet 2006

CMBR only:

GZK cutoff consistentwith UHECR protons

Augerlimits:

5

UHECR Emissivity

yrMpc

erg

cMpcr

cmerg

horizonUHECR

344

321

10

/)(

10lossUHECRCR tdVdEudVdtdE /)/()/(

crt horizonloss /

knee

ankle

6

UHECR Emissivity

yrMpc

ergeVE UHECRp 3

4410)(

1020 0.41019 0.81018 31017 40

)10/()(

)(106

)(

2024

345

3

eVEMpcr

EJ

yrMpc

erg

horizon

UHECR

Sources of UHECRs need to havea local luminosity density (emissivity) of 1044 erg/Mpc3-yr

lossUHECRCR tdVdEudVdtdE /)/()/( crt horizonloss /

Yamamoto et al. (2007)

7

UHECR Acceleration by Relativistic Jets

x

Proper frame (´) energy density of relativistic wind with apparent luminosity L

BuB 8

2

22

1

4

cR

Lu

Lorentz contraction R´= R

R´= R/

Maximum particle energy

)/(max RBZeRBQE

eVsergsL

ZE

)10/(

102146

20max

What extragalactic sources have (apparent isotropic) L >> 1046 ergs s-1?

Those with (apparent isotropic) L > 1046 ergs s-1

8

Subset of LAT Bright Source List, 0FGL (Fermi Gamma-ray LAT): Abdo et al. arXiv:0902.1340 (ApJ, in press)

LAT Bright AGN Sample (LBAS): Abdo et al. arXiv:0902.1559 (ApJ, in press)

Fermi Bright Sources (3 month source list)

August 4 – October 30, 2008

0FGL: 205 LAT Bright Sources

Test Statistic > 100Significance > 10

132 |b|>10 sources114 associated with AGNs

Compare EGRET:31 >10 sources (total)(10 at |b|>10)

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3C 296

UHECRs from 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

FRII/FSRQ

FRI/BL Lac

FRI/II dividingline at radio power1042 ergs s-1

BL Lacs: optical emission line equivalent widths < 5 Å

10

Minimum luminosity density of Radio Galaxies from LBAS

Luminosity Density of Blazars

1044 ergs Mpc-3 yr-1

11

Centaurus A

Need > 1046 erg s-1 apparent power to accelerate UHECR protons by Fermi processes

Cen A power: Bolometric radio luminosity: 4×1042 erg s-1

Gamma-ray power (from Fermi): 5×1041 erg s-1

Hard X-ray/soft -ray power: 5×1042 erg s-1

UHECR power: few ×1040 erg s-1

~100 kpc × 500 kpc lobes

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What is Average Absolute Jet Power of Cen A?

Hardcastle et al. 2009

Total energy and lifetime:Cocoon dynamics (Begelman and Cioffi 1989 for Cyg A)

Use synchrotron theory to determine minimum energy B field, absolute jet power Pj. Jet/counter-

jet asymmetry gives outflow speed:

)8

()(2

22'*parbj u

BcrP

13

Mean B-field and Average Absolute Jet Power in Cen A

Hardcastle et al. 2009

Pj(Cen A) 1044 erg s-1

Apparent jet power 100 x larger?

14

Search for UHECRs Enhancements from Radio Galaxies and Blazars

Blue: Auger, > 56 EeV (1◦)Red: HiRes > 56 EeV (1◦) Magenta: AGASA, > 56 EeV (1.8◦) Orange: AGASA, 40-56 EeV (1.8◦)

Pink and purple circles: angular deflections of UHECRs with 40 EeV and 20 EeV from source AGN, respectively, in the galactic disk magnetic field.

Green circles represent angular deflections in assumed 0.1 nG intergalactic magnetic field, assuming no magnetic-field reversals.

GC GC

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UHECRs from Gamma Ray Bursts

GRB: Burst of rays accompanying black-hole formation

Classes of GRBs– Long duration GRBs

(collapse of massive stellar core)

– Short hard class of GRBs

(coalescence of compact objects)

– Low luminosity GRBs

(Galactic coordinates)

-ray Light Curve of GRB

All-sky ray mapin Galactic coordinates

Swift mission discovered that short hard class of GRBs are related to old stellar populations (Gehrels et al. 2005)

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> 20 keV fluence distribution of 1,973 BATSE GRBs (477 short GRBs and 1,496 long GRBs).

670 BATSE GRBs/yr (full sky)

GRB X-ray/-ray Emissivity

GRB fluence:12210 yrcmergs

)1;4000(

1075.0

3/4

104

1344

3

1222

zMpcd

yrMpcergs

d

yrcmergsd

GRB

)10( 20eVUHECRGRB Vietri 1995; Waxman 1995

(Band 2001)(independent of beaming)Baryon loading

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Wick, Dermer, and Atoyan 2004

Ultra-high Energy Cosmic Rays from Gamma Ray Bursts

Inject 2.2 spectrum of UHECR

protons to E > 1020 eV

Injection rate density determined by birth rate of GRBs early in the history of the universe

High-energy (GZK) cutoff from photopion interactions with cosmic microwave radiation photons

Ankle formed by pair production effects (Berezinsky and colleagues)

Test UHECR origin hypothesis by detailed fits to measured cosmic-ray spectrum

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Effects of Different Star Formation Rates

Hopkins & Beacom 2006-ray signatures of UHECRs at source can confirm this hypothesis

Fermi LAT GRBs as of 090510Fermi LAT GRBs as of 090510

192 GBM GRBs~30 short GRBs8 LAT GRBs

Light Curves of GRBs 080825C, 081024BLight Curves of GRBs 080825C, 081024B

First LAT GRB. Note:• delayed onset of high-energy emission• extended (“long-lived”) high-energy

rays

Preliminary

First short GRB with >1 GeV photon detected

Before the burst (T0-100 s to T

0)

GRB 080916C: Luminous Fermi GRB

• ±30 deg region around GRB 080916C– GRB at 48˚ from the LAT boresight at T

0

• RGB= <100 MeV, 100 MeV - 1 GeV, >1 GeVDuring the burst (T

0 to T

0+100 s)

Black region = out of FoV

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GRB 080916C: Notable Firsts

Largest number, ~145, of >100 MeV photons from a GRBLargest number, ~145, of >100 MeV photons from a GRB

Allows time-resolved spectral studiesAllows time-resolved spectral studies First high-energy 100 MeV – GeV detection of a GRB with known redshift z = First high-energy 100 MeV – GeV detection of a GRB with known redshift z =

4.35±0.2 from GROND photometry on 2.2 m in La Silla, Chile (4.35±0.2 from GROND photometry on 2.2 m in La Silla, Chile (Greiner et al. 2009Greiner et al. 2009)) Large fluence burst (2.4×10Large fluence burst (2.4×10-4 -4 ergs s ergs s-1-1) at 10 keV – 10 GeV energies) at 10 keV – 10 GeV energies

Apparent isotropic energy release 8.8×10Apparent isotropic energy release 8.8×1054 54 erg erg

Supports the black-hole jet paradigm of GRBSupports the black-hole jet paradigm of GRB Highest energy photon, Highest energy photon, EE = 13.22 = 13.22+0.70+0.70

-1.54-1.54 GeV from a GRB with measured redshift GeV from a GRB with measured redshift

Constraints on the jet Doppler factor/bulk Lorentz factor, emission regionConstraints on the jet Doppler factor/bulk Lorentz factor, emission region

Implications for Extragalactic Background Light (EBL) modelsImplications for Extragalactic Background Light (EBL) models

Limit on Quantum Gravity mass scaleLimit on Quantum Gravity mass scale Significant Significant 4s delay between onset of >100 MeV and 100 keV radiation 4s delay between onset of >100 MeV and 100 keV radiation

Implications for high-energy spectral modeling, leptonic/hadronic originImplications for high-energy spectral modeling, leptonic/hadronic origin

Results published in Science (Abdo et al., vol. 323, issue 5922, page 1668, 2009)

Light Curves of GRB 080916CLight Curves of GRB 080916C

Again, two notable features:1. Delayed onset of high-energy emission2. Extended (“long-lived”) high-energy raysseen in both long duration and short hard GRBs

8 keV – 260 keV

260 keV – 5 MeV

LAT raw

LAT > 100 MeV

LAT > 1 GeV

T

0

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Interpretation of Delayed Onset of >100 MeV Emission

Razzaque, Dermer and Finke (2009)

Random collisions between plasma shellsRandom collisions between plasma shells Separate emission regions from forward/reverse shock systemsSeparate emission regions from forward/reverse shock systems Second pair of colliding shells produce, by chance, a harder spectrumSecond pair of colliding shells produce, by chance, a harder spectrum Expect no time delays for >100 MeV in some GRBs, yet to be detectedExpect no time delays for >100 MeV in some GRBs, yet to be detected Opacity effectsOpacity effects Expansion of compact cloud, becoming Expansion of compact cloud, becoming optically thin to >100 MeV photonsoptically thin to >100 MeV photons Expect spectral softening break evolve Expect spectral softening break evolve to higher energy in time, not observed to higher energy in time, not observed Up-scattered cocoon emission Up-scattered cocoon emission Synchrotron-self-Compton for < MeV Synchrotron-self-Compton for < MeV External Compton of cocoon photons, arriving External Compton of cocoon photons, arriving late from high-latitude, to >100 MeVlate from high-latitude, to >100 MeV

Toma, Wu, Meszaros (2009)

Proton synchrotron radiation Proton synchrotron radiation Inherent delay to build-up proton synchrotron flux which sweeps into LAT energy range from high-energy end

GRB 080916C

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Synchotron Radiation from UHE Protons

Instantaneous energy flux (erg cm-2 s-1); variability time tv, redshift z

Implies a jet magnetic field

b is baryon loading-parameter (particle vs. -ray energy density)

B gives relative energy density in magnetic field vs. particles

> min 1033 from opacity arguments

236

22

22

2 )1(

4

4

v

LL

tc

dz

cR

du

2/1

33

5

1.010060

)(2)(

s

t

stkGB v

Bb

v

bB

26

Fermi Acceleration of Protons in GRB Blast Waves

Protons gain energy on timescales exceeding Larmor timescale,

implying acceleration rate

is acceleration efficiency

Saturation Lorentz factor:

Proton saturation frequency (in mec2 units):

Observer measures a time

for protons to reach

cm

Be

ppacc

,

2/15

2/1

82/1

2/1, )10/(

102

4

9

BB

B

m

m

f

cr

e

ppsat

)10/(

106.1

8

27

113

71

,,

fe

ppsatpsat m

m

zz

pacc, sBBem

cmzt

Te

psat 2/3

3

2/1

3

22/1

5

10/01.061

27

Time for Proton Synchrotron Radiation to Brighten

processes induce second generation electron synchotron spectrum at

i.e., ~ 500 MeV for standard parameters

Time for proton synchrotron radiation to reach sat,e:

253

32

2, )10/(

10

16

27

12

3

B

m

m

B

B

z fe

p

cresat

tcl tsat Bcr

B

me

mp

64 f

81

4

3

1 z

mpcBcr

e B 2

mp

me

1.4( /10)

3 B 52 s

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Long GRBs as the Sources of UHECRs

Maximum energy of escaping protons

Long GRB rate 2fb Gpc-3 yr-1 at the typical redshift z 1–2

10 smaller at 100d100 Mpc due to the star formation

fb > 200 larger due to a beaming factor

60E60 EeV UHECR deflected by an angle

IGM field with mean strength BnGnG coherence length of 1 Mpc

Number of GRB sources within 100 Mpc with jets pointing within 4 of our line-of-sight is

If typical long duration GRBs have a narrow core accelerating UHECRs,

then GRBs could account for Auger events within GZK radius.

eVB5

320

)10/(102

4.4 ZBnG E60 1d100

1/ 211/ 2

2/31

260

2)200/(30 EBf nGb

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Extended High Energy Emission

All LAT All LAT detected GRBs show significant detected GRBs show significant high energy emission extending after the high energy emission extending after the low energy emissionlow energy emission has (almost) has (almost) disappeared below detectabilitydisappeared below detectability (discovered originally with EGRET on (discovered originally with EGRET on Compton Observatory; Compton Observatory; Hurley et al. 1994Hurley et al. 1994))

GRB080916C shows HE emission that GRB080916C shows HE emission that extends more than 1000 sec. beyond the extends more than 1000 sec. beyond the detectable keV-MeV emissiondetectable keV-MeV emission Could be due to …Could be due to …

Delayed arrival of Compton-scattered synchrotron photons (SSC)Delayed arrival of Compton-scattered synchrotron photons (SSC)Though no hard spectrum observed as expected from SSC, unknown reason for delayThough no hard spectrum observed as expected from SSC, unknown reason for delay

Emission from >TeV Emission from >TeV -ray induced cascade in CMB -ray induced cascade in CMB (e.g., Razzaque, Meszaros & Zhang 2004)

Requires very small (<10Requires very small (<10-16-16 G) intergalactic magnetic field G) intergalactic magnetic field Long-lived hadronic emissions Long-lived hadronic emissions (Böttcher and Dermer 1998)

Abdo et al., Science, 323, 1668 (2009)Abdo et al., Science, 323, 1668 (2009)

GRB 080916C

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UHECR Origin

Ruled out: Galactic sourcesyoung neutron stars or pulsars, black holes,GRBs in the Galaxy

Particle physics sourcessuperheavy dark matter particles in galactic halotop-down models, topological defects

Clusters of galaxies

Viable: Jets of AGNs: radio-loud or radio-quiet? Cen A!, M87?

GRBs:

Magnetars? Others?

Requires nano-Gauss intergalactic magnetic field

UHECRs accelerated by black-hole jets

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Possible photon targets for p +:

Internal: synchrotron radiation

External: accretion disk radiation (UV)

(i) direct accretion disk radiation:

(ii) accretion disk radiation scattered in the

broad-line region (Atoyan & Dermer 2001)

quasi-isotropic, up to RBLR

~ 0.1-1 pc

Impact of the external accretion-disk radiation

component: high p-rates & lower threshold energies:

Neutral Beam Model for UHECRs in Blazars

=7 (solid)

=10 (dashed)

=15 (dot-dashed)

(red - without ADR)

(for 1996 flare of 3C 279)

32

Sreekumar et al. (1998)

Blazars as High Energy Hadron Accelerators

astro-ph/0610195

Synchrotron and IC fluxes from the pair-photon cascade for the Feb 1996 flare of 3C279

(3C 279)

dotted - CRs injected during the flare; solid - neutrons escaping from the blob, dashed - neutrons escaping from Broad Line Region (ext. UV) dot-dashed - rays escaping external UV field (from neutrons outside the blob)3dot-dashed- Protons remaining in the blob at l = R

BLR

Powerful blazars / FR-II Neutrons with E

n > 100 PeV and rays with E > 1 PeV take away

~ 5-10 % of the total energy injected at R<RBLR

33

Hadronic -Ray Emission from Blazars

Gamma rays from hadron-induced cascades: Orphan -ray flares

34

Neutrinos: Predicted 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.

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UHE neutrons and rays

energy and momentum transport from AGN core

UHE -ray pathlengths in CMBR:

l ~ 10 kpc - 1Mpc

for En ~ 1016 - 1019 eV

• Neutron decay pathlength:

ld (

n) =

0 c

n (

0 ~ 900 s)

ld ~ 1 kpc – 1 Mpc

for E ~ 1017 - 1020 eV

solid: z = 0 dashed: z = 0.5

36

d ~ 200 Mpc

l jet

~ 1 Mpc (lproj

= 240 kpc)

Deposition of energy through

ultra-high energy neutral beams (Atoyan and Dermer 2003)

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

Pictor A

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Hadronic GRB Modeling in Collapsar Scenario

Escaping neutrondistribution

Injected protondistribution

Cooled proton distribution

Nonthermal Baryon Loading Factor fb = 30

pulses

one

cmergs

tot

sec50

,

1032

5

Energy injected in protons normalized to GRB synchrotron

fluence

Forms neutral beam of neutrons, rays, and neutrinos

38

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

D = 100