QUASARs and Rotating Black Holes - Landessternwarte Heidelberg ...

lsw.uni.heidelberg.de

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

More magazines by this user
Similar magazines