ACTIVE
GALACTIC
NUCLEI
ACTIVE GALACTIC NUCLEI
Galaxies that emit a very large amount of energy from a pointlike (unresolved) region at their center
Size of emitting region smaller than the solar system Radiation is nonthermal.
Extends for a very broad region of wavelength.
Broad emission lines
Interpreted as Doppler shift velocity of gas vgas ~ 0.1 c
A ZOO of different objects
SEYFERT GALAXIES (Carl Seyfert 1943) Galaxies with bright blue nucleus, broad lines
Radius Emitting Galaxies
Some galaxies (Cygnus A) have large radius emitting lobes
QUASARS
radio sources with pointlike (starlike) optical counterpart Discovery in 1963 3C 273 m = 13.1 source
M. Schmidts finds redshift of z = 0.158
Seyfert1 Galaxy NGC 5548 Optical spectrum
Broad component 5900 Km/sec Narrow component 400 Km/sec
Z = 4.90 QUASAR
z = 5.82
z = 5.99
z = 6.28
Quasar Hosts seen by HST
Redshift distribution of 7236 Quasars
HewittBurbidge catalogue (1993)
L 1048 erg/sec
z = 0.031 z = 0.034
z = 0.117 z = 0.129 z = 0.044 z = 0.048
AGN
observed by Cherenkov Telescopes
BL Lacertae
“BLAZARS” :
Quasars, BLLac Objects
Brightests, most variable objects
BL Lacertae
Whole Earth Blazar Telescope (WEBT)
BLACK HOLE PARADIGM
Energy Source :
Gravitational Potential Energy
converted into radiation via viscous dissipation in an accretion disk surrounding a Black Hole
SIZE
Luminosity (Eddington) Constraint
Time variability: R < ct
MASS
"FORCES" acting on an electron at radius r
p, e bound by
Coulomb interaction
Condition of the existence of the source:
Accretion is positive
Fueling of an AGN
3C 219
Optical
Radio
JETS
JET Invisible
Counter JET
Radio Lobes Hot Spots
CYGNUSA
VLA telescopes
VLBI
(Very Long Baseline Interferometry)
M87
UNIFIED MODEL of AGN's
NON Spherical (Axisymmetric) Emission
Wide Variety of AGN's phenomena is a combination of
Real Differences in a small number of physical parameters M, dM/dt, ...
Apparent Differences due to the orientation of the AGN with respect to the observer.
Active Galactic Nucleus
at different scales
From S. Ciprini
From Ciprini
NGC 4258
Very solidly established Black Hole
SPECTRAL ENERGY DISTRIBUTION (SED)
Mkn501 Spectral Energy Distribution
H. Krawczinsky
et al. Astroph/0204229
Absorption
in intergalactic space ⇒ e+ e
Mrk 501
Clear Evidence for the accelerations of e±
Natural to expect
the “coacceleration”
of protons (nuclei)
Unambiguous Signature:
Neutrino Emission