33 terms

Dwight Russell - Test 4

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Terms in this set (...)

What is the size of the Milky Way
100,000 light years across
What is the number of stars in the Milky Way?
200 billion stars
How long does it take for the Sun to go around the Milky
Way once?
230 million years
What is the overall shape of the Milky Way?
Barred Spiral
What are the regions of the Milky Way? (3)
1. Bulge
2. Disk
3. Halo
HALO REGION
1. What does it contain?
2. Shape
3. Type of Stars
4. Gas/dust
1. Contains Globular clusters
2. Spherical shape
3. Pop. II stars
4. Very little interstellar gas & dust
Galactic Disk Region
1. Shape
2. Arms
3. Type of Stars
4. Gas/Dust
1. Flattened Shape
2. Spiral Arms (with Pop. I stars)
3. Pop. I AND Pop. II stars
4. Interstellar gas & dust
Bulge Region
1. Location
2. Shape
3. Type of Stars
4. Gas/Dust
5. What is in the middle
1. Center of the galaxy
2. Football shape
3. Pop. II stars
4. Little Gas & dust
5. Supermassive black hole at center
Methods of determining the size & position of the center of the Milky Way
Global Clusters
What is the density wave theory for spiral arm formation?
Galactic Traffic Jam
What is the self propagating star formation for spiral arm formation?
Supernova explosions
Population I Stars
-Lots of blue stars
-Located in spiral arms of galaxies
-Hot & young stars
-Gas & dust = present
Population II Stars
-Few blue stars
-Older stars
-Little gas & dust
What are the 3 major types of galaxies in the Hubble Classification Scheme?
1. Elliptical
2. Spiral/Barred Spiral
3. Irregular
Elliptical Galaxy Properties
-Hardly any gas & dust
-Primarily made of Pop. II Stars
Spiral/Barred Spiral Galaxy Properties
-Characterized by a disk with spiral arms
-Have Central Bulges = "Barred Spirals"
-In b/n Irregular and Elliptical as fas as gas & dust
-Most common type of galaxy
Irregular Galaxy Properties
-Lots of gas & dust
-Lots of Pop. I stars
What type of galaxy is the Milky Way?
Barred Spiral
Where is the gas and dust in a spiral galaxy?
In the disk
What type of galaxy has a disk?
Spiral Galaxy
What causes different types of galaxies?
Collisions
Rich Clusters
-Have hundreds of thousands of galaxies w/n them
-Includes super massive elliptical galaxies
Poor Clusters
-Small
-Have only a handful of galaxies
Local Group
-The galaxy cluster that we are apart of
-Poor Cluster
What is the nearest Rich Cluster to the Milky Way?
Virgo Cluster
Big Bank Outline
1. Planck Epoch
2. Grand Unification Epoch
3. Inflationary Epoch
4. Electroweak Epoch
5. Quark, Hadron, and Lepton Epoch
6. Photons, Nucleosynthesis and the Cosmic Background Radiation
7. Dark Ages
8. "Modern" Era = Stars form
1. Planck Epoch
-First stage of Big Bang
-Mystery b/c we lack a quantum theory of gravity
2. Grand Unification Epoch
Forces except gravity are unified
3. Inflationary Epoch
Universe expands rapidly
-Smaller than a proton to bigger than a melon
--->Supported experimentally
4. Electroweak Epoch
Weak and electromagnetic forces act as one
5. Quark, Hadron, and Lepton Epoch
What we think of a "normal" elementary particle form and survive
6. Photons, Nucleosynthesis and the Cosmic Background Radiation
Atoms form (hydrogen and helium) and cosmic background radiation "decouples" from matter
7. Dark Ages
Atoms exist but stars don't