Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Types of Galaxies
Galaxies: <ul><li>A large group of stars, gas, and dust held together by gravity </li></ul><ul><li>May contain as many as ...
3 Types of Galaxies <ul><li>Spiral Galaxies </li></ul><ul><li>Elliptical Galaxies </li></ul><ul><li>Irregular Galaxies </l...
Spiral Galaxies <ul><li>Have spiral arms that wind outward from inner regions </li></ul><ul><li>Arms are made up of bright...
Example of Spiral Galaxy <ul><li>Our Galaxy, the Milky Way </li></ul><ul><li>The visible Milky Way suggests our galaxy is ...
The Milky Way As We See It
Example of a Spiral Galaxy <ul><li>The Andromeda Galaxy </li></ul><ul><li>The Andromeda Galaxy (2 million light years away...
Elliptical Galaxies <ul><li>Shaped like large 3D ellipses </li></ul><ul><li>Can be football shaped or round </li></ul>
Irregular Galaxies <ul><li>Don’t fit into the other classifications </li></ul><ul><li>Smaller than the other 2 types of ga...
Who do we know which way galaxies are moving? <ul><li>Doppler Effect </li></ul><ul><ul><li>The wavelength of sound or ligh...
Star Light Spectrums <ul><li>Spectrum lines are shifted towards the blue end </li></ul><ul><li>Is this star moving toward ...
Star Light Spectrums <ul><li>Spectrum lines are shifted towards the red end. </li></ul><ul><li>Is this star moving toward ...
Doppler Shift <ul><li>The amount of shift is bigger if the emitting object is moving faster.  </li></ul><ul><li>Thus if we...
Upcoming SlideShare
Loading in …5
×

Galaxies

1,021 views

Published on

Notes from Mr. Olandese's DES Class on the different types of Galaxies and how they move.

Published in: Education
  • Be the first to comment

Galaxies

  1. 1. Types of Galaxies
  2. 2. Galaxies: <ul><li>A large group of stars, gas, and dust held together by gravity </li></ul><ul><li>May contain as many as one trillion stars that can be millions of light years apart </li></ul><ul><li>Separated by millions of light years from each other </li></ul><ul><li>Grouped into clusters (Our cluster is called the Local Group and contains 30+ galaxies) </li></ul>
  3. 3. 3 Types of Galaxies <ul><li>Spiral Galaxies </li></ul><ul><li>Elliptical Galaxies </li></ul><ul><li>Irregular Galaxies </li></ul>
  4. 4. Spiral Galaxies <ul><li>Have spiral arms that wind outward from inner regions </li></ul><ul><li>Arms are made up of bright stars and dust </li></ul>
  5. 5. Example of Spiral Galaxy <ul><li>Our Galaxy, the Milky Way </li></ul><ul><li>The visible Milky Way suggests our galaxy is a flat disk </li></ul><ul><li>All the stars we can see from Earth are in the Milky Way </li></ul>
  6. 6. The Milky Way As We See It
  7. 7. Example of a Spiral Galaxy <ul><li>The Andromeda Galaxy </li></ul><ul><li>The Andromeda Galaxy (2 million light years away, member of the Local Group) </li></ul>
  8. 8. Elliptical Galaxies <ul><li>Shaped like large 3D ellipses </li></ul><ul><li>Can be football shaped or round </li></ul>
  9. 9. Irregular Galaxies <ul><li>Don’t fit into the other classifications </li></ul><ul><li>Smaller than the other 2 types of galaxies </li></ul><ul><li>Orbit the Milky Way </li></ul>
  10. 10. Who do we know which way galaxies are moving? <ul><li>Doppler Effect </li></ul><ul><ul><li>The wavelength of sound or light emitted by an object is shifted if the object is moving </li></ul></ul><ul><li>If the object is coming toward you, the light is shifted toward shorter wavelengths, blue shifted . </li></ul><ul><li>If the object is going away from you, the light is shifted toward longer wavelengths, red shifted . </li></ul>http://phys.kookmin.ac.kr/~key/physengl/dopplerengl.htm http://www.phy.ntnu.edu.tw/java/Doppler/Doppler.html http://www.mhhe.com/physsci/astronomy/arny/student/anims/27_5.htm
  11. 11. Star Light Spectrums <ul><li>Spectrum lines are shifted towards the blue end </li></ul><ul><li>Is this star moving toward you or away from you? </li></ul>
  12. 12. Star Light Spectrums <ul><li>Spectrum lines are shifted towards the red end. </li></ul><ul><li>Is this star moving toward you or away from you? </li></ul>
  13. 13. Doppler Shift <ul><li>The amount of shift is bigger if the emitting object is moving faster. </li></ul><ul><li>Thus if we know the original wavelength, we can figure out the speed. </li></ul><ul><li>We do know the wavelengths of certain elements like Hydrogen (H) and Helium (He). </li></ul><ul><li>Thus for many objects in outer space we can tell </li></ul><ul><ul><li>Is it coming toward us? </li></ul></ul><ul><ul><li>Is it going away? </li></ul></ul><ul><ul><li>If so, how fast is it moving toward us or away from us? </li></ul></ul><ul><ul><li>But this does not tell us how fast it is moving sideways. </li></ul></ul>

×