Introduction to the High Energy Astrophysics

Introductory lecture

Cosmic Ray Spectrum

(nuclear component)

Energy eV

„Knee”1 particle/m2 yr

Par

ticl

e F

lux

( m

2 s

sr G

eV )

-1

1 particle/m2 s

„Ankle”1 particle/km2 yr

1 J 61018 eV

Zakres wysokichenergii

E

2 .5 P

arti

cle

Flu

x

Energy (eV)

SNR

Black Holes

Pulsary

Crab Nebula : : wide frequency range electromagnetic

spectrum - 20 decades fotons – over 9

decades !

COMPTEL EGRET

HEGRA100 keV – 100 TeV

CELESTE

Ee ~1015 eV

IC: syn,opt, IR, micro, CMB

B=160 G

SYN

Quasars

Mkn 421

SYN IC

czas w dniach

eV TeV

keVTeV

High variability: one looks into vicinity of the central black hole

Takahashi et al. 2000

Radiosources

Solar magnetosphere

20

Stars

Radio Infrared Visible light X-raysVHE

gamma rays

DustCosmic

electronaccelerators

B

Cosmic proton

accelerators

magnetic fieldadjusts relativeheight of peaks

~

SpectralEnergyDistribution:Energy emitted perlog(E) interval

Astronomical osbervation cover a wide range of electromagnetic waves

with characteristic frequencies or photon energies:

Astronomy uses observations of electromagnetic signals spanning over 20 decades in frequency

109 Hz – radio1011 Hz – far IR1014 Hz – close IR1015 Hz – optical (eV)1016 Hz – UV1018 Hz – X-rays (keV)1021 Hz – soft gamma rays (MeV)1024 Hz – high energy gamma rays (GeV)1027 Hz – very high energy gamma rays (TeV)

108

1029

Observational windows of gamma ray astronomy :

LE or MeV : 0.1 -100 MeV (0.1 -10 + 10 -100*)

HE or GeV : 0.1 -100 GeV (0.1 -10 + 10 -100*)

VHE or TeV : 0.1 -100 TeV (0.1 -10 + 10 -100*)

UHE or PeV : 0.1 -100 PeV EHE or EeV : 0.1 -100 EeV

are open in ranges of MeV, GeV, i TeV:

LE,HE – observations from space VHE, .... -observations from the Earth surface

* few scientific results

Basic emission processes with CR particles

Elektrons:

- Synchrotron emission („SYN”)

- inmverse Compton emission („IC”)

- nonthermal bremsstrahlung (usually not significant)

Protons:

- interactions p-p pions photons

Synchrotron emission ("SYN")of relativistic electrons spiraling in the magnetic field

222 )sin(2)( BUcP BTsyn

Emission time scale

24

19 )(105.2

Btsyn

Emmitted energy with maximum near (B-4 B/[10-4 G])

24100~3.0 Bc Hz

Dla B-4=1 i E~

GeV -> 108 HzTeV -> 1014 Hz PeV -> 1020 Hz

lat

for above B and E, respectively, ~106, ~103 i ~1 lat

Inverse Compton emission ("IC") of relativistic electrons scattering low energy photons

Emission time scale (with Uo,-10 = Uo/[10-10 erg/cm3])

110,0

110, )(10~

Ut TIC lat

oTTIC UcP 2, 3

4

In the Thompson range ( o < mec2 , above: K-N)

Energies of scattered photons2 o

For example, for scattering of CMB photons (o~10-4 eV)and Ee = 1 GeV, 1 TeV, 1 PeV one receives ' = 100 eV, 100 MeV, 100 TeV

Cosmic objects of interest for High Energy Astrophysics

quasarsbalzarsSyfert 1Syfert 2AGNMAS jetskpc-scale jetsradio lobeshot spots in radio lobes

neutron starsblack holesNSXBBHXBaccreting X-ray pulsarsrotation powered pulsarsmilisecond pulsarsplerionsSNRcataclysmic variablesmicroquasarsSgr A*stellar winds near O/B

GRBGRB afterglowsoft gamma ray repeatersmagnetars

Solar protuberancesinterplanetary shock wavesEarth magnetosphereCME cosmic rays

high energy neutinos