1. Active Galaxies Definition – –Amount of Energy –Type of Energy Non-thermal Polarized Other characteristics –Emission spectra Hydrogen – Balmer series & Lyman alpha (121.6 nm), UV N V (124.0 nm) C IV (154.9 nm) O VI (103.5 nm) Forbidden emission lines

2. Synchrotron radiation F( )=F o   between 0.7 and 1.2 Active galaxy general characteristics - –L>10 37 W (>10 billion L  ) –Non-thermal emission –Excessive amount of IR, UV, radio, x-ray –Small region of rapid variability –Bright nucleus –Explosive appearance/Jets –Broad emission lines

3. ULIRG Very high redshift (z) Very young/early galaxies Lots of IR/dust Lots of star formation Earliest of all galaxies?

4. Seyferts Characteristics –Bright nuclei, 100 billion L  –Spiral like (90%) 10% Normal spirals have Seyfert characteristics –Non-thermal, synchrotron continuum –Two different types Type I –More common –Wide spectral features – high velocity –More luminous –UV, x-ray

5. Type 2 –Narrow emission lines –Strong in IR Range of types, 1.5, 1.7, etc. Model? –Accretion disk (non-thermal) High energy photons (x-ray, uv) –Black hole –Jets Radio, or boosted to higher energies –Dust – IR source for type 2 –High/low velocity clouds

6. Type 1 Type 1.5 Type 2

7. Radio Galaxies 1% of all galaxies 10% of active Level of emission is used to classify Two groups –Compact –Extended Jets – synchrotron, bipolar outflow Lobes, 50-3000 kpc, electrons, protons

8. 3 types of extended radio galaxies –Classical double lobes High luminosity cD galaxies, ellipticals –Wide-angle tails, bent tails –Narrow tail sources Low luminosity, high velocity galaxies Compact sources have different energy profile (  ~ 0)

9. Cygnus A Radio, x-ray images 100 kpc

10. M87 3 billion M  Black hole

11. M87 X-rayradio both

13. Quasars Quasi-stellar objects (QSOs) Characteristics –Star-like appearance –Broad emission lines –Absorption lines, especially if z>2 –Other absorption features Broad features with velocities up to 0.2 c Low velocity sharp lines – absorption/emission Lyman – alpha forest – wide range of velocities

14. Most quasars visible light sources, or higher energy (x-ray, gamma-ray) Non-thermal spectrum (a between 0, 1.6) Variable – quick High z values –Quasar evolution –Brightness varies with z (brighter at high z) –Very few at very high z –Peak at z~2.5 (1000x more/volume than today) –Peak of 1 QSO per 100 Mpc 3

19. Unified Model Look at model for Seyferts –Can be applied to all types of active galaxies –Must have a black hole! –Million – billions of M  –Infall rates of 100 M  /year needed –High luminosities – short lived

20. History? Step 1. First objects formed – what were they? ULIRG or Quasars or regular Galaxies? ULIRG Rare, hard to find QSOs – stand out, but not common at very high z Most distant object observed, z=10 (maybe) Step 1a. Formation of first galaxies, z=5-8? With massive black holes? First QSOs formed also (not all galaxies are QSOs) Step 2. Peak of QSO formation at z=2.5

21. Step 3. QSOs start to fade Not feeding them enough Step 4. QSOs become Seyferts? Or Radio? Less powerful, logical step Seyfert phase – relatively short Whole AGN phase – few billion years? Step 5. Normal, boring galaxies, with no major activity

22. Feeding the Monster Black hole powers AGNs Can you over feed a black hole? Yes! Radiation pressure limits infall Eddington Luminosity – L Edd = 3 x 10 4 (M BH /M  ) L 

23. Abell 1835 IR1916 z=10! Much smaller than MW! Most distant object?

24. Most distant QSO SDSS J1148+5251 z=6.42

25. Gravitational Lensing

26. How many quasars? Lynx arc