1. AGN: Quasars
By:
Jay Hooper

2. Outline Types of AGN Components of AGN Differences between AGN
General Overview

3. Types of AGN AGN – Active Galactic Nuclei
Quasars
QUAsi-StellAr Radio source
Blazars
Seyfert
Type 1
Type 2
Are thought to be the same objects viewed in different orientations

4. Components of AGN Supermassive black hole: 108 - 109 solar masses
Broad-line region: dense clouds of ionized and heated gas, by ultraviolet and x-ray photons, rotating a velocities of 1000’s of km/s
Accretion disk: Matter ripped apart by tidal forces spiraling inward. Approx. consumption of one solar mass of matter per year is required to power a quasar

5. Torus: doughnut-shaped region of molecular gas and dust which is heated by the central source, emitting infrared light, but which obscures the central black hole, disk and broad-line region from observers viewing the quasar edge-on.
Narrow-line region: cone-shaped region of illuminated clouds
Jets: Oppositely-directed streams of plasma thought to be discharged due to the winding up of magnetic fields in an accretion disk that forms around a massive black hole converting gravitational and rotational energy into bulk outflows at high speeds perpendicular to the disk.

7. Differences between AGN
Quasars
A clear view of the central engine source.
High-energy gamma-rays. Usually 100 MeV or more, even up to the GeV range
Produces more light and energy comparable to galaxies,in a region as big as our solar system

8. Blazars
believed to be a quasar which has one of its relativistic jets pointed directly toward the Earth. Therefore not as luminous as quasars.
Same energy levels as a quasar, but have been recorded in the TeV range!

9. Seyfert – two types divided by their spectral emission features
Seyfert – two types divided by their spectral emission features. Emitters of low energy gamma-rays on the order of 100KeV. Produce on the order of .1 to 10 times the light and energy of our galaxy
Type 1
Has a hydrogen emission feature with very large widths. Due to tilted jet angle.

10. Type 2
Has a hydrogen emission feature with much narrower widths. AGN viewed edge on.

11. General Overview
Distances are computed by their apparent red-shifts, with the farthest recorded z=5.5 corresponding to about 14 billion ly
This is roughly a time period when the universe was 1/10 its present age

12. Give off radiation in the form of all wavelengths
Only about 10% are strong radio sources. The rest are radio quiet.
Size of source determined by time in variation of intensity
if an object varies significantly in brightness over a period of a week, it cannot be larger than a light-week in size.

13. Superluminal motion up to 10c.
bursts of synchrotron plasma shot out almost, but not quite, toward us at near speeds of c.

14. References http://skyandtelescope.com/news/article_964_1.asp