CH 16 ISP 205

Galaxies and Super Massive Black Holes

Type of galaxy that would be at the center of a galaxy cluster

A large elliptical galaxy

Elliptical galaxies

Galaxy with a round bulge and no disk. Only has a halo component and very little star formation.

Spiral galaxy

Galaxy in a thin disk shape with a central bulge and outer halo. Has disk and halo stars.

Irregular Galaxy

Galaxy with no distinct spiral arms or central bulge, giving it a chaotic and amorphous appearance

We determine the distance of a Cepheid by

Determining the luminosity from the period-luminosity relation and then applying the inverse square law for light.

What is the best standard candle for measuring distances to very far off galaxies?

A white dwarf supernova

Why do all the galaxies in the universe seem to be moving away from us?

Expansion causes Galaxies to repel each other.

Galaxies in the ______ are among the oldest.

Local Group

Key assumption in successful models for galaxy formation:

Some parts of the universe were slightly denser than others.

Galaxies with bigger black holes in the center also have:

A greater mass of stars in central bulges.

Luminosity of a quasar is generated in a region the size of:

The solar system.

Primary source of a quasar's energy

Gravitational potential energy.

Standard candle method

Uses objects with known luminosity to find distances.

Parallax Method

Measures the distance to stars by observing their apparent shift in position as the Earth orbits the Sun.

How is the age of the universe related to Hubble's constant?

Inversely related

Evidence for a supermassive black hole at the center of galaxies

The mass influences star and gas orbits.

When a galaxy is redshifted it is:

Moving away from us

When a galaxy is blueshifted it is:

Moving towards us

How does Hubble’s constant tell us the age of the universe?

It relates the velocities and distances of all

galaxies

What role do black holes play in the life of a galaxy?

causes galaxies to eventually stop forming stars.

How did astronomers get the slope of Hubble’s Law?

Plotting galaxies' distances against how fast they are red shifting.

Initial conditions of protogalactic clouds Greatly influence:

Early galaxy type formation

Later galaxy collisions can Greatly influence:

Existing galaxy's shape and properties. May transform spirals into ellipticals

Initial Conditions in Protogalactic Clouds included:

Varied angular momentum and density.

Later Collisions with Other Galaxies included:

Morphological Transformation, Starburst Activity and Gas Stripping.