QUASARs and Rotating Black Holes - Landessternwarte Heidelberg ...

QUASARs
and
Rotating Black Holes
Max Camenzind
Landessternwarte Königstuhl
Heidelberg 2002

Contents
• Quasars as cosmological objects
Æ pre-Quasar era: 1908 – 1960
Æ Quasar era: 1963 – 2000
Æ post-Quasar era: 2000 - ….. (> 100 000)
• Quasars are broad band emitters
Æ accretion, dust and hot ion tori !
• Models for Quasars: > 8 parameters !
Æ r < 100 pc in Spirals, r < 1 kpc in Es/S0s
• Quasar search: 2dF, SDSS, ….
• Jetty Quasars: interesting minority …

5 Lectures on Quasars
• Active Quasars: definition, taxonomy, history,
spectra and global models Æ Friedmanology;
• Quasar Remnants: Remnants in centers of
galaxies, correlations, galaxy types, examples
Æ Spheroidal structure of galaxies;
• Jetty Quasars: Jets and radio galaxies, jet
speeds, plasma, synchrotron and IC emission
Æ Kerr Black Hole at the very center;
• Hidden Quasars: Type I and II, dust, X-rays;
• Early Quasars: from the first stars to z=5
Æ Black Holes and Gamma-Ray Bursters

Astronomical Object Type
• Quasar stands nowadays as a synonyme for Active
Galactic Nuclei Æ Galaxies are „dead Quasars“;
• Æ central activity in a galaxy not related to stars:
• (i) Luminous UV-emission from a compact core in
the nucleus of the galaxy – in quasars only the core
is visible (stellar like appearance) Æ UV Excess
• (ii) strongly broadened emission lines Æ Surveys
• (iii) time variability (> hours);
• (iv) compact radio core (Sag A*);
• (v) X-ray, gamma-ray and TeV emission.
• In bright quasars, the radiation from a region
comparable to the solar system is several hundred
times brighter than the galaxy emission.

Pre-Quasar Era
• 1908: emission lines from NGC 1068 (E. Fath,
Lick Obs.; V.M. Slipher, Lowell);
• 1913: detection of the „jet“ in M 87 (Curtis);
• 1916: Schwarzschild metric – but no astronomical
relevance seen at that time !
• 1926: Andromeda is extragalactic, and
1930: Universe of galaxies expands (Hubble) –
but not aware of Friedman solution !
• 1943: new examples of emission line galaxies
(Carl Seyfert) Æ Seyfert galaxies: NGC 4151,
NGC 4051, NGC 1275, NGC 3516, NGC 7469;
• 1959: Seyfert activity takes about 100 Mio years
(Woltjer), since 1% of all spirals are active.

Messier 87
1913 – 2002
Anatomy of a
Dead Quasar

Radio Surveys Æ Quasar Era
• 3CR catalog (178 MHz, Bennett 1961) down to
a limiting flux of 9 Jy (1 Jy = 10 -26 W m -2 Hz -1 );
• PKS survey on the southern hemisphere (408
MHz, Ekers 1969) down to 4 Jy; later at 1410
MHz (1 Jy) and 2650 MHz (0.3 Jy);
• More sensitive 4C survey down to 1 Jy (1965);
• Ohio survey: very luminous sources (OH 471);
• 3C 48, 3C 273 first identified sources (1963).
• Later it turned out that only a minority is RL !

The quasar 3C 273

SDSS
z = 0.2
SDSS
z = 0.5

SDSS
z = 2.05
SDSS
z = 4.96

High
Redshift
Quasars
(SDSS,
NGST)

Historical Interlude
• 1963: Maarten Schmidt 3C 48, 3C 273;
• 1963: Roy Kerr finds Black Hole solution (PRL) !
• 1960s – 1970s: hundreds of QSOs detected;
• 1978: Einstein Observatory launched by NASA –
first imaging X-ray satellite
Æ Seyfert galaxies and QSOs are X emitters;
• Æ 2002 Nobel Prize: R. Giacconi;
• 1980s: Radio galaxies and Quasars are mapped
with VLA and MERLIN Æ DRAGN Homepage !
• 1990s: Compton Gamma Ray Observatory
Æ some Quasars are high energy emitters.
• > 1990: Black Hole Remnants are detected in
nearby galaxies: M 87, M 31, Sag A*, … Æ ~ 40
• 2001: Highest redshift for a Quasar: z = 6.25

Global Continua of Quasars
• Energetisation by accretion from the parsecscale
onto the central Black Hole, emitted
mainly in the optical-UV-sX spectral region;
• Thermal emission from dust distributed on
the scale from a few parsecs to hundreds of
parsecs in the bulge of the host galaxies,
emitted at wavelengths from 500 µm to a few
µm (ISO data for bright PG Quasars, see
Haas et al. 2000, A&A 354, 453; 2002);
• Hard X-emission from the inner torus around
the Black Hole (ASCA, Chandra, XMM).

X-Rays

------- ~ 10 pc -------- >

Black Hole
Paradigm
Popular Model, but wrong !
Å pc Æ

My favourite
Quasar
Model
Å kpc Æ
giant Elliptical
Dust heated
by central Quasar
M_H = 10^9 M_S
Scattered UV light

Parameters of Quasars
• Mass and Radius of central stellar Bulge
(radii < 1 kpc);
• Mass and velocity profiles of gas and dust in
Bulge (turbulent + rotation);
• Mass of Black Hole M H;
• Angular momentum of Black Hole J H;
• Accretion rate towards Black Hole
Æ Relative accretion modulo mass important;
• Inclination angle with respect to line of sight;
• Magnetic fields in Bulge region.
• Æ Relative accretion rate determines the
physical state of the bulge !

Quasar Samples
• Luminous Quasars (PG) at low redshifts,
120 m_B < 16 (Schmidt & Green 1983)
with known radio, X-ray (ASCA), IR (IRAS,
ISO) properties.
• Hewitt & Burbidge (1993): m_B < 18
Æ 7236 Quasars with known redshifts;
• 2dF Quasar Survey (AAT): m_B < 21;
2 strips 75° x 5° Æ 25‘000 Quasars
expected (2002: 23‘000);
• SDSS (ongoing): m_B < 22 Æ 100‘000
Quasars; Æ highest redshifts z = 6.2 !

erg / s]
46
L_f [10
1
10 -1
10 -2
10 -3
10 -4
10 12
10 13
ISO-PHOT - Optical
10 14
10 15
1634+706
1206+459
1302-102
1613+658
10 16
f [Hz]

Mass Estimates
• (i) Eddington mass (lower limit): L acc < L Edd
Æ M Q > M Edd = L Edd / 0.1*c² .
• Æ M Q > 10 9 M S for bright quasars;
• Æ M Q > few Mio solar masses for Seyferts;
• (ii) Spectral mass: UVX-bump;
• (iii) Virial mass: M Q = f*R_BLR*sigma²/G;
R BLR = c*tau; sigma Å V FWHM of BLR;
• Growth time under Eddington accretion:
• t Ed = 40 Mio yrs (independent of mass).
Æ exp(20) = 480 Mio
Æ BH can grow in 500 Mio yrs to 10 9 M S !

Peterson 2000

No local
Quasars !

SDSS
Quasars
• Preliminary
analysis:
• 2625 QSOs
• 529 deg²
• Slice 2.5 deg

2dF 2001

Result
• Quasars evolve in
• (i) space density;
• (ii) intrinsic luminosity Æ quasars at higher
redshifts are more luminous.
• Æ High redshift quasars are hosted by
massive galaxies (ellipticals) !
• Æ Large samples of quasars which must
be investigated in UVX-bump, HX-ray,
radio and IR properties !
• Æ Cosmological consequences: clustering
as a function of redshift.

Jetty Quasars
• One Jansky Catalog Æ Radio Galaxies
and Quasars.
• Structure of 3C sources
• Æ FR II sources
• Æ FR I sources
• Continua of RL Quasars: jet emission
• Æ High redshift radio galaxies

3C 273

Jetty
Quasar