5.1.1 Types of Galaxies

Types of Galaxies
5.1.1

By Caitlin Ford

Objectives

- identify the features of each type of galaxy

- list the features of active galaxies and quasars

- explain how galaxies are classified

Open Ended

The Milky Way is a barred-spiral galaxy. What other types of galaxies do you know?

Other Galaxies?!

Until 1923, we thought the Milky Way galaxy made up the entire universe!

Edwin Hubble studied Andromeda, and by 1929 he discovered 46 galaxies.

Classification of Galaxies

Elliptical - has a round or oval shape, no spiral arms

Spiral - shaped like a pinwheel, has a central disk with spiral arms

Barred-spiral - similar to a spiral, but has a bar connecting its spiral arms

Lenticular - looks like a lens, has a central bulge but no spiral arms

More types...

Since Hubble's time, we'ved discovered 2 more types of galaxies.

 

barred-lenticular galaxies and irregular galaxies

Categorize

Options (8)

Categorize the galaxies based on their pictures.

Spiral

Elliptical

Irregular

Barred-Spiral

Active Galaxies

Active galaxies emit extremely high amounts of radiation in the form of gas. All active galaxies a have supermassive black hole at the center.

 

Active galaxies emit more radio waves and the black hole ejects highly energetic particles in opposite directions.

 

Quasar (quasi-stellar radio source) is a type of active galaxy. It is 10 to 100,000 times brighter than the Milky Way; this brightness comes from radiation created by gas being sucked toward the black hole.

Labelling

Each row is a different type of galaxy. Label the types.

Drag labels to their correct position on the image

elliptical

spiral

lenticular

irregular

Drag and Drop

All active galaxies have a​

Placeholder

at the center.

Drag these tiles and drop them in the correct blank above

supermassive black hole

massive planet

bright nebula

quasar

Great job!

Today, you learned:

 

- the classification of galaxies proposed by Hubble

- features of different types of galaxies

- features of active galaxies and quasars