Cosmic AcceleratorsAstrophysics with High Energy Particles

Thomas LohseHumboldt University Berlin

Graduiertenkolleg “Physik an Hadronen-Beschleunigern” Klausurtagung, 17.10.2006

The Cosmic Ray Spectrum

Power Laws

Shock Accelerationpredicts FSource E2

Discovery Balloon Flight Victor Hess, 1912

sola

r m

odul

atio

n

E2.7, mostly protons

transition toheavier nuclei E3.1

mostly Fe?

Knee

?

Ankle

EAS DetectorsDirect Measurements

transition tolighter nuclei ?

Open questions after 90 years

What and where are the sources?

How do they work?

Are the particles really accelerated?...

…or due to new physics at large mass scales?

And how do cosmic rays manage to reach us?

Production in Cosmic Accelerators

protons/nucleielectrons/positrons

p

0

radiation fields and matter

p

e Inverse Compton(+Bremsstr.)

Experimental Techniques ( E 10 GeV )

InstrumentedWater / Ice

Scintillator or Water Č

Č-Telescope

Č

Fluorescence Detector

Hadron-Detector

Fluorescence

Primary (Hadron,Gamma)

Air Shower

Atmospheric (4)

Primary (4)

, e,

R&DRadio-Detection

Acoustic-Detection

1. Cosmic rays beyond the ankle

2. Neutrinos from cosmic ray sources

3. Gammas from cosmic ray sources

1. Cosmic rays beyond the ankle

2. Neutrinos from cosmic ray sources

3. Gammas from cosmic ray sources

OutlineOutline

p beyond ankle

Greisen-Zatsepin-Kuzmin Cut-Off:Energy loss in cosmic microwave

background (CMB)p(100 EeV) + (CMB) p + , n +

p(100 EeV)p

p below ankle isotropized in B-fields

E eV102010191018

E3

FE

cut-off

reprocessed p

no GZK cut-off?

triplet

model fit to HIRes data

AGASA

HIResFly’s Eye

AGASA

AGASA: surface detector array

HIRes: fluorescence light detector

Spectra consistent allowing for 30% systematic energy shift…

The Pierre Auger Project3000 km2 Hybrid Detector

1600 Water Č-Detectors 75% installed

4 Fluorescence Sites

AGASA

Energy Calibration of Surface Detectors

14% duty cycle

Present systematics:Calibration 12%Fluorescence yield 15%

Clean EeV Hybrid Events

contemporaneous atmospheric monitoring

statistically limited

up to now…statistically limited

up to now…

• calorimetric measurement independent of primary

composition independent of air shower details

First Look at 3 EeV Energy Spectrum( from surface detector array )

Data: Jan. 2004 – Jan 2005

Exposure: 1750 km2 sr yr AGASA + 7%

Events: 3525

Power Law Fit

2.4d.o.fχ

EEd

Id

2

03.084.2

systematic errors

AUGER best fit

preliminary Calibration uncertainty

1. Cosmic rays beyond the ankle

2. Neutrinos from cosmic ray sources

3. Gammas from cosmic ray sources

Amundsen-Scott South Pole Station

South PoleDome

Summer camp

AMANDA

1500 m

2000 m[not to scale]

IceCube(in construction)

The Main Players presently: • Amanda / IceCube, South Pole Ice• BAIKAL, Water of Lake Baikal

+ future Mediterranean detectors

upward (2 coverage)

preliminarypreliminary

horizontal

vertical

atmospheric

Search for Diffuse Cosmic Neutrinos

1:1:1 flavour flux ratio

E2-Flux Limit

add directional & temporal constraints …

IceCube 3 years

h24 h

90

90

Unbinned Search for Clusters

AMANDA 2000-2003

preliminary

AMANDA 2000-2003

preliminary

Significance Sky Map

Maximum Excess 3.4

max. excess from random

skymaps3.4

92%

AMANDA Search for Transient Sources

events

time

sliding window • time window: 40 / 20 days• angular bin: 2.25°-3.75°

fixed a priori

Source Events Backgr. window doublets Prob.

Markarian 421 6 5.58 40 days 0 Close to 1

1ES1959+650 5 3.71 40 days 1 0.34

3EG J1227+4302 6 4.37 40 days 1 0.43

QSO 0235+164 6 5.04 40 days 1 0.52

Cygnus X-3 6 5.04 20 days 0 Close to 1

GRS 1915+105 6 4.76 20 days 1 0.32

GRO J0422+32 5 5.12 20 days 0 Close to 1

12 Objects tested (over 4 years), no triplets found … BUT …

…

5 events

backgrounddublet window

66 day triplet

WHIPPLE E > 0.6 TeV

HEGRAE > 2 TeV

AMANDA – 1ES1959+650 – 2.25o search bin sizerevisited a posteriori

Orphan -flare (not seen in

X-rays)

Statistical significance hard to tell … but promising!Lessons learned: Multimessenger & multiwavelength

studies important. Use -ray flares (not only X-rays)…

The first cosmic ray neutrino ???

1. Cosmic rays beyond the ankle

2. Neutrinos from cosmic ray sources

3. Gammas from cosmic ray sources

H.E.S.S. CANGAROO III

MAGIC

Veritas

in construction

Cherenkov Telescopes (3rd Generation)

3.1. Supernovae

Synchrotron radiation

Pulsar Wind Nebula:Electron wind from central

pulsar heats the cloud

The Standard Candle for TeV -AstronomyCrab Supernova 1054 a.D. d = 2 kpc

optical

1 lig

htye

ar

But what about hadrons (protons and nuclei)?

Cassiopaeia A Supernova 1658 a.D. d = 2,8 kpc

X ray picture

“Shell Type” SNR:

• no electron wind from pulsar

• gamma signal from shell regions not totally drowned in that of electron wind

• good source class to observe hadron acceleration

resolution

H.E.S.S. 2004E 210 GeV

RX J1713.73946

resolution

H.E.S.S. 2004E 210 GeV

RX J1713.73946

First Resolved Supernova Shells in -Rays

H.E.S.S. 2005E 500 GeV

RX J0852.04622

Strong correlation with X-ray intensitiesStrong correlation with X-ray intensities

• SN-Shells are accelerating particles up to at least 100 TeV!• But are these particles protons/nuclei or electrons?

E2 d

N/d

E

log(E)

Stars

radio infrared visible light X-rays VHE -rays

CMB

Dust

CosmicElectron

Accelerators BEe

Electron or Hadron Accelerator?

Synchrotron Radiation Inverse Compton

e

e

EdNd

B, e

e

EdNd BEe

Cosmic Proton

Accelerators

, p

p

Ed

Nd Matter Density

0Synchrotron Radiation of Secondary Electrons

EGRET

2.0 2.0

B 7, 9, 11

GB 7, 9, 11

G

Electron accelerator fits for RX J1713.73946 :• Continuous electron injection over 1000 years• Injection spectrum: power law with cutoff

• IC peak not well described• B-field low for SNR shell

• large & injection rate bremsstrahlung important

• needs tuning at low E

αeE

B 10

G B 10

G

2.0, 2.25, 2.5 2.0, 2.25, 2.5H.E.S.S.H.E.S.S.

Continuous proton injection over 1000 years Injection spectrum: power law, index 2 Different cutoff shapes & diffusion parameters

Proton accelerator fit:

H.E.S.S. RX J1713.73946

3.2. Inner Glactic Plane30 ≲l ≲ 30

3 ≲ b ≲3

H.E.S.S. Scan of Inner Galactic Plane

Resolution

14 new sources, all extended! Possible counterparts: (plus previously known ones)

5 SNR3 Pulsar 3 ???

HESS J1837069

HESS J1834087

HESS J1825137

HESS J1813178

HESS J1804216

G0.90.1HESS J1747281

Galactic CentreHESS J1745290

HESS J1745290

HESS J1713381

RX J1713.73946HESS J1708410

HESS J1702420HESS J1640465

HESS J1634472

HESS J1632478HESS J1616508

HESS J1614518

HESS J1834-087

HESS J1804-216 HESS J1640-465

TeV-Gamma-RayRadioX-Ray

… a new source class: “Dark Accelerators”

Five sources known: TeV J20324130 (HEGRA)

HESS J1303631 HESS J1614518

HESS J1702420 HESS J1708410

What are these sources? Are they hadron accelerators?

• extended• hard spectra, • steady emission

3.3. Galactic Centre

HESS J1837069

HESS J1834087

HESS J1825137

HESS J1813178

HESS J1804216

G0.90.1HESS J1747281

Galactic CentreHESS J1745290

HESS J1745290

HESS J1713381

RX J1713.73946HESS J1708410

HESS J1702420HESS J1640465

HESS J1634472

HESS J1632478HESS J1616508

HESS J1614518

Chandra GC surveyNASA/UMass/D.Wang et al.

CANGAROO (80%)

Whipple

(95%)

H.E.S.S.

Chandra GC surveyNASA/UMass/D.Wang et al.

CANGAROO (80%)

Whipple(95%)

Contours from Hooper et al. 2004

Galactic Centre: A pointlike TeV- source

H.E.S.S. (95%); MAGIC similar

Astrophysical Source Candidates:

• 3106 M⊙ black hole Sgr A

─ EMF close to rotating black hole─ Accretion shocks

• Supernova Remnant Sgr A East─ Expanding shock waves

Radio

H.E.S.S.

Systematicpointing error

Radio Contour

Sgr A*

Sgr A EastSNR

no visible cut-off rather large mass

measured flux large cross-section and/or DM density

… or maybe dark matter annihilation ?

10-13

10-12

10-11

0,1 1 10

E2 F

(E)

[Te

V/c

m2 s]

E [TeV]

20 TeV Neutralino20 TeV Kaluza Klein particle

… unlikely !

H.E.S.S. MAGICGC

Crab

Galactic Centre Neighbourhood

~150 pc

Galactic CentreHESS J1745290

SNR G0.90.1HESS J1747281

EGRET GeV--sources

...point sources subtracted

first resolved detection of diffuse TeV--radiation cosmic rays (hadrons) interacting with molecular clouds

~150 pc

Galactic Centre Neighbourhood

molecular clouds density profiles

HESS J1745290

Cosmic Ray Spectrum at the GC...

diffuse radiation

expected flux for CR spectrum

observed on earth

Cosmic rays are much harder and have 3

larger density around the GC

Cosmic rays are much harder and have 3

larger density around the GC

is very different from the one at earth

Possible reason:

Close-by source population

Possibly single SN-explosion

3.3. Active Galaxies

General Active Galactic Nuclei (AGN):• Supermassive black holes, M 109 M

• accretion disk and relativistic jets

Blazar-Typ: Jet points towards the earth• Doppler-boost TeV -radiation

Blazars

E

dN/d

E

Measurement of EBL ( Cosmology )

Physics of compact objects,acceleration/absorption in jets,…

EdN

/dE

Absorption in (infrared) extragalactic background light (EBL)

(TeV) + (EBL) e+e-

e+

e-

Cut-off Energy and -Ray Horizon

PG 1553113

H 2356 (x 0.1) = 3.1±0.2 Preliminary

EBL Unfolding of Measured Spectra

1 ES 1101 = 2.9±0.2

EBL

H 2356 (x0.1) = 3.1±0.2

Hardest plausiblesource spectrum = 1.5

Hardest plausiblesource spectrum = 1.5

Too muchEBL

Lower Limits(Galaxy Counts)

New Upper Bound on EBL Density

Direct IRTSMeasurements

Assumed shape for rescaling

H.E.S.S. upper boundfrom spectral shapes of

1ES 1101-232 (z = 0.186) H 2356-309 (z = 0.165)

EBL density seems 2 smaller than expected! Little room for EBL sources other than galaxies (early stars…)

Upper Limits

excluded by H.E.S.S.

Summary• Cosmic ray puzzle persists…but is under pressure by

massive attack from EAS-arrays, - and -telescopes

• Progress in understanding knee, ankle and GZK-region AUGER data disfavour small scale anisotropies

• Cosmic -detection in multi-messenger campaigns ?Neutrino astronomy might start sooner than expected !

• Major break-through in TeV--astronomy supernova shells are 100 TeV accelerators large population of extended galactic TeV sources discovered first microquasar-candidates established as TeV accelerator diffuse galactic TeV emission (Milagro, H.E.S.S.) TeV- from Active Galactic Nuclei at large red-shifts, …

AGN

Black Holes

Microquasars

Gamma Ray Bursts

Pulsars

Dark Accelerators

Supernovae

The Cosmic Accelerator Cocktail ?