Active Galaxies Active Galaxies and Quasars!and Quasars!

Types of GalaxiesTypes of Galaxies

Normal Galaxy and Active GalaxyNormal Galaxy and Active Galaxy Normal GalaxyNormal Galaxy

Just a normal galaxy Just a normal galaxy Emits mostly visible radiationEmits mostly visible radiation

Active GalaxyActive Galaxy Thousands of times brighter than Thousands of times brighter than

Normal GalaxyNormal Galaxy Emit different radiation; more energy, Emit different radiation; more energy,

but it is less visiblebut it is less visible

Energy of an Active Energy of an Active Galaxies Galaxies

The energy of an The energy of an active galaxy is active galaxy is determined by its determined by its core.core.

Non-thermal process. Non-thermal process. (Meaning the (Meaning the process is not related process is not related to temperature!)to temperature!)

The lifetime energy The lifetime energy of an active galaxy of an active galaxy can be compared to can be compared to the total energy of a the total energy of a black hole.black hole.

Properties of Active Properties of Active GalaxiesGalaxies

High luminosityHigh luminosity Non-thermal Non-thermal

radiationradiation Small, bright coreSmall, bright core Jets or explosive Jets or explosive

appearanceappearance Non-stellar emission Non-stellar emission

featuresfeatures Possible “super Possible “super

massive” black hole massive” black hole in centerin center

Seyfert GalaxySeyfert Galaxy Classified as “in-between”Classified as “in-between” Possible evolutionary linkPossible evolutionary link Seyfert Galaxies appear Seyfert Galaxies appear

similar to normal ones, similar to normal ones, however their core is 10,000 however their core is 10,000 times more luminous.times more luminous.

Core is called Galactic Core is called Galactic nucleus, this is where the nucleus, this is where the radiation jets shoot out fromradiation jets shoot out from

Most of core’s energy is Most of core’s energy is “invisible” and infrared“invisible” and infrared

Galaxy rotates very fast Galaxy rotates very fast around its core, thus the around its core, thus the creation of all the radiant creation of all the radiant energy.energy.

Rapid changes in the amount Rapid changes in the amount of emitted energy, this shows of emitted energy, this shows that the source of energy that the source of energy must be very compactmust be very compact

Radio GalaxyRadio Galaxy Most of energy released is Most of energy released is

in the in the radio portion of in the in the radio portion of the electromagnetic the electromagnetic spectrumspectrum

Two types of radio galaxies: Two types of radio galaxies: lobe radio galaxy and core lobe radio galaxy and core halo galaxy.halo galaxy.

Lobe radio galaxyLobe radio galaxy Energy is released from giant Energy is released from giant

regions called radio lobes, regions called radio lobes, hardly any energy is emitted hardly any energy is emitted from the core.from the core.

Radio Lobes are roundish Radio Lobes are roundish clouds of radiation; not visible.clouds of radiation; not visible.

Some lobes can be 10 times Some lobes can be 10 times the size of the Milky Way; can the size of the Milky Way; can emit 10 times the amount of emit 10 times the amount of energy energy

Core-Halo Radio GalaxyCore-Halo Radio Galaxy

Most of energy emitted is Most of energy emitted is from a small central from a small central nucleus, 1 pc across. This nucleus, 1 pc across. This is referred to as the core.is referred to as the core.

Energy also emitted from a Energy also emitted from a halo around the core.halo around the core.

Core-halo galaxies can be Core-halo galaxies can be up to 18mpc across; the up to 18mpc across; the output of radio energy is output of radio energy is the equivilant to the Milky the equivilant to the Milky WayWay

A large jet of energy is A large jet of energy is ejected from the center of ejected from the center of the galaxythe galaxy

QuasarsQuasars Are believed to be extremely bright and Are believed to be extremely bright and

extremely far away from earth.extremely far away from earth. Most distant object found in the Universe, closest Most distant object found in the Universe, closest

270 mpc.270 mpc. Luminosity can range from 10 to 10,000 times the Luminosity can range from 10 to 10,000 times the

Milky Way. Some are so bright they can be seen at Milky Way. Some are so bright they can be seen at 12 billon light years.12 billon light years.

Most of their energy is emitted in the infrared Most of their energy is emitted in the infrared spectrumspectrum

Are about 1 kpc acrossAre about 1 kpc across They posses much of the same characteristics They posses much of the same characteristics

as active galaxies.as active galaxies. Like active galaxies the energy is drawn from Like active galaxies the energy is drawn from

a small central core.a small central core.

Quasars… again…..YAYQuasars… again…..YAY The small central The small central

core of Quasars is core of Quasars is expected to be a expected to be a “super massive” “super massive” black hole.black hole.

All galaxies are All galaxies are expected to have expected to have these in the center.these in the center.

Quasars also posses Quasars also posses jets of matter.jets of matter. These jets appear These jets appear

faintfaint

Relating them allRelating them all

Characteristics of Active Galaxies Characteristics of Active Galaxies and Quasarsand Quasars High luminositiesHigh luminosities Energy emission is non-stellarEnergy emission is non-stellar Energy is high variable; small coreEnergy is high variable; small core Emit jets of energyEmit jets of energy Rapid internal motion of the energy Rapid internal motion of the energy

producing region.producing region.

Central engine of active Central engine of active galaxiesgalaxies

Energy requirements.Energy requirements. Energy cannot be described as combinations Energy cannot be described as combinations

of things.of things. To much, to little spaceTo much, to little space

Energy is gamma and X-rayEnergy is gamma and X-ray Energy ProductionEnergy Production

The energy is a result of extremely fast The energy is a result of extremely fast rotation caused the black hole.rotation caused the black hole.

This is the accretion diskThis is the accretion disk http://astro.estec.esa.nl/SA-general/Projects/Inhttp://astro.estec.esa.nl/SA-general/Projects/In

tegral/black_hole_500.mpgtegral/black_hole_500.mpg

Energy emissionEnergy emission

10 to 20% of total mass energy is 10 to 20% of total mass energy is radiated away.radiated away.

Particles enter a magnetic field an spin Particles enter a magnetic field an spin in there releasing energy into space.in there releasing energy into space. This magnetic field become tangled and This magnetic field become tangled and

creates the radio lobes.creates the radio lobes. The radio lobes and jets serve as a The radio lobes and jets serve as a

conductor of energy so it can be taken conductor of energy so it can be taken from the core and released into space.from the core and released into space.

Active galaxyActive galaxy

Central coreCentral core

Super massive Black holeSuper massive Black hole Have mass of around 100 billion sunsHave mass of around 100 billion suns The theory is that all galaxies have The theory is that all galaxies have

super massive Black holes in their core.super massive Black holes in their core. The Gravitational force from the core The Gravitational force from the core

creates an accretion disk and produces creates an accretion disk and produces large amounts of non-visible energy.large amounts of non-visible energy.

GRAVITATIONAL GRAVITATIONAL LENSING!LENSING!

The light of another The light of another galaxy is bent by the galaxy is bent by the gravitational field of gravitational field of one in front of a one in front of a galaxy or close to it. galaxy or close to it. The bend in space in The bend in space in turn bends the light turn bends the light so it appears that so it appears that there are twin there are twin galaxies around galaxies around another separate another separate galaxy.galaxy.

Does the position of the galaxy in front Does the position of the galaxy in front of another affect the lensing that is of another affect the lensing that is

taking place?taking place? Yes it does. The Yes it does. The

position of the galaxy position of the galaxy that is blocking the that is blocking the one behind it can one behind it can change the way the change the way the light bends meaning light bends meaning there would be a more there would be a more extreme bend on one extreme bend on one side making the galaxy side making the galaxy behind appear closer behind appear closer to the one blocking it to the one blocking it and its twin look and its twin look farther away.farther away.

Evolution of GalaxiesEvolution of GalaxiesOne Theory…….One Theory…….

Beginning with the Beginning with the highly luminous highly luminous quasars quasars

Decreasing in violence Decreasing in violence through the radio and through the radio and Seyfert galaxies and Seyfert galaxies and ending with normal ending with normal spirals and ellipticals spirals and ellipticals

The central black The central black holes that powered the holes that powered the early activity are still early activity are still there at later times; there at later times; they simply run out of they simply run out of fuel as time goes onfuel as time goes on

Evolution of GalaxiesEvolution of GalaxiesAnother Theory…..Another Theory…..

A Merger and an A Merger and an Irregular Galaxy combine Irregular Galaxy combine to form a Black Holeto form a Black Hole

This newly formed Black This newly formed Black Hole combines with a Hole combines with a Quasar to form a Super Quasar to form a Super massive Black Hole.massive Black Hole.

Over time, the Black Over time, the Black Hole loses its power and Hole loses its power and slowly deteriorates into a slowly deteriorates into a Seyfert Active Galaxy.Seyfert Active Galaxy.

This Active Galaxy This Active Galaxy continues to lose power continues to lose power and eventually and eventually deteriorates into a deteriorates into a Normal Spiral GalaxyNormal Spiral Galaxy

This is what its like WHEN This is what its like WHEN WORLD COLLLIDEEE…WORLD COLLLIDEEE…Galaxy Galaxy

collision collision

This is a series of pictures depicting This is a series of pictures depicting what it may look like if The Milky what it may look like if The Milky Way and Andromeda were to collide Way and Andromeda were to collide and come into contact with each and come into contact with each other. The images depict the stars other. The images depict the stars as particles of constant brightnessas particles of constant brightness..