Active galaxies / Active galactic nuclei (AGN)

1
Active galaxies / Active galactic nuclei (AGN)
Central engine variability put limit on size R
c ?var Schwarzschild radius Rs 2 G M /
c2 Rs size approx Uranus orbit for 109
M? Accretion allows conversion of 0.1mc2
(fusion only 0.7) Radiation pressure will
larger than gravity if L gt LEDD Accretion disk
very hot continuum source gt X-rays Broad line
region, dense ionised clouds, rapid
moving Narrow line region, dilute ionised
clouds, slower reverbration mapping Obscuring
torus with dust and molecular gas,
sublimation evacuate central part -gt
torus Relativistic (superluminal) Jets, and
radio Lobes
2
(No Transcript)
3
Unified AGN models
Idea all AGN are basically the same
phenomena Differing due to different viewing
angle and scale Face on view see all
components Sy1, QSO if looking into jet Bl
Lac (Blazar) Edge on view see only hot torus
and NLR, Sy2 Why some radio loud while others
not? Unified BH model not perfect, but nothing
else works
4
Unified Model
5
Spiral seyfert2 with radio jets
Seyfert1
6
QSO evolution - where are they now?
Debate if fall off at zgt3 is real
There must be many dead QSOs around in the local
universe!
7
Kinematical evidence for BH in M87
Grav redshifted X-ray em-lines detected in Sy1s
8
(No Transcript)
9
Relation between black hole mass and sigma of
host galaxy a realtion between BH and Spheroid
Mass -- Black Hole doesnt care about disk --
Co-evolves with spheroid/bulge!
10
Clusters And Large Scale Structure (chapt. 4)
11
M33
LeoI
Sex A
12
(No Transcript)
13
Tidal drag on NGC205 from M31
14
Local Group
15
HCG31 Galaxy Evolution/ Transformation Caught
in action
16
Rich clusters Virgo and Comairregular vs
regular
(large spiral fraction) (mostly early
types)) (more relaxed)
17
Hot gas in clustersX-ray emitting through
thermal bremsstrahlung
Efficient way of finding clusters
18
Butcher-Oemler effect, etc
As we look back in time, the spiral fraction
of Rich clusters become higher and higher
(BO) Cluster and Galaxy transformation Interacti
ons galaxy mergers cluster merger galaxy
harassment ram pressure stripping diffuse
intracluster light stars gas vs Hot
intracluster gas
19
Masses of clusters
Virial theorem M RA ?v2 / G - does it
apply? X-ray gas in Hydrostatic equilibrium
- does it apply? Gravitational lensing
it does apply but only gives mass contrast -
Methods agree fairly well (factor of 2)
20
Gravitational lensing
21
Einstein ring
22
Abell 2218, strong lensingcf weak lensing
(statistical)
23
Angular distribution of Abell-clusters Brightest
cluster galaxy method allows rough space
distribution to be inferred
24
Virgo supercluster
Bound? -Not relaxed LargeScale Flows
25
Sponge-like topology of universe
CfA Redshift Survey Great wall Voids! Finger of
god
26
SDSS
27
Intergalactic matter
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
Gunn-Peterson effect
32
Cosmic shear
Challenging! - Effect on each individual galaxy
tiny - Only visible through lareg and deep
samples
33
Measuring Clustering
- Count in cells - 2-point corellation function