https://youtu.be/oAVjF_7ensg Name ______Date ______Section______
ACTIVITY 28 The Hubble Deep Field North
Learning Goals In this activity, you will use the Hubble Deep Field North to explore the evolution and distribution of galaxies in the universe. As you work through the activity you will: 1. Analyze the galaxies in and the structure of the Hubble Deep Field North. 2. Identify Hubble types and relate types to colors of galaxies. 3. Relate the colors of galaxies to the possible dominant stellar populations. 4. Summarize the importance of the Hubble Deep Field North to our understanding of the evolution of galaxies.
Step 1—Galaxy Types
In this activity, you will examine the Hubble Deep Field North (HDFN), an image of very distant space as it was far back in time. After this image was obtained, the 10-meter, Earth-based Keck telescope was used to observe the faint blue galaxies in the image. Astronomers have concluded that the small blue shards are among the most distant objects ever seen. See if you can pick out some of these faint blue galaxies in the image that your instructor is projecting. These objects may represent galaxies caught in the act of formation. In all, the number of galaxies in the image implies that there are about 40 billion galaxies in the observable universe. Take a close look at Figure 28.1, the HDFN. Noted next to many of the galaxies is the redshift, also known as z, for that galaxy. You will need those redshifts in Step 2 of this activity. There are a number of clearly identifiable galaxy types included in the HDFN. You may want to refer to the source image as you work: http://ned.ipac.caltech.edu/level5/Deep_Fields/mirror/hdfn/index.html. 1. Make your own map of the Hubble Deep Field North by locating 15–20 galaxies. Sketch them, placing them on the grid of Figure 28.2 according to their locations in the image. 2. Label each galaxy sketched with the Hubble type of that galaxy, and create a key on the grid for identification. (Clicking on a galaxy in the online source image gives a “close-up” view through five different filters that will help in the classifying.) 3. The galaxies have noticeably different colors, as you have noted in the image source. Do you see any overall pattern between the color of the galaxy and its Hubble type? Based on what you know about the colors of stars, give a brief description of the types of stars that make up the different types of galaxies.
137 Name ______Date ______Section______
ACTIVITY 28 The Hubble Deep Field North
Learning Goals In this activity, you will use the Hubble Deep Field North to explore the evolution and distribution of galaxies in the universe. As you work through the activity you will: 1. Analyze the galaxies in and the structure of the Hubble Deep Field North. 2. Identify Hubble types and relate types to colors of galaxies. 3. Relate the colors of galaxies to the possible dominant stellar populations. 4. Summarize the importance of the Hubble Deep Field North to our understanding of the evolution of galaxies.
Step 1—Galaxy Types
In this activity, you will examine the Hubble Deep Field North (HDFN), an image of very distant space as it was far back in time. After this image was obtained, the 10-meter, Earth-based Keck telescope was used to observe the faint blue galaxies in the image. Astronomers have concluded that the small blue shards are among the most distant objects ever seen. See if you can pick out some of these faint blue galaxies in the image that your instructor is projecting. These objects may represent galaxies caught in the act of formation. In all, the number of galaxies in the image implies that there are about 40 billion galaxies in the observable universe. Take a close look at Figure 28.1, the HDFN. Noted next to many of the galaxies is the redshift, also known as z, for that galaxy. You will need those redshifts in Step 2 of this activity. There are a number of clearly identifiable galaxy types included in the HDFN. You may want to refer to the source image as you work: http://ned.ipac.caltech.edu/level5/Deep_Fields/mirror/hdfn/index.html. 1. Make your own map of the Hubble Deep Field North by locating 15–20 galaxies. Sketch them, placing them on the grid of Figure 28.2 according to their locations in the image. 2. Label each galaxy sketched with the Hubble type of that galaxy, and create a key on the grid for identification. (Clicking on a galaxy in the online source image gives a “close-up” view through five different filters that will help in the classifying.) 3. The galaxies have noticeably different colors, as you have noted in the image source. Do you see any overall pattern between the color of the galaxy and its Hubble type? Based on what you know about the colors of stars, give a brief description of the types of stars that make up the different types of galaxies.
DO JUST THE MAPPING AND LABELING AND ANSWERING OF QUESTION #3 ON THE 137 BOTTOM OF PAGE 137. HAND IN PAGES 137 - 140. ACTIVITY 28 ● The Hubble Deep Field North 139
FIGURE 28.2
Redshifts of galaxies in the Hubble Deep Field North 150
113
75
38 Number of galaxies at that redshift Number of galaxies
0 0.2 0.6 1 1.4 1.8 2.2 2.6 3 3.4 3.8 4.2 Galaxy Redshift Z
FIGURE 28.3
HAND IN THE Hubble Deep Field PARTICIPATION ACTIVITY - PAGES 137 - 140 - AS YOU LEAVE.
PLEASE WRITE IN BOTH SECTION LETTERS OR TA’S NAME!
GO DAWGS! Learning goals: be able to ….
• Summarize the evidence supporting elliptical galaxies formed from collisions and mergers of spiral galaxies.
• Summarize what is meant by the “bottom-up” or hierarchical process for galaxy formation. Question: Why so many different kinds of galaxies?
Current theory for formation of structure in Universe • Primordial fluctuations in density existed • Gas and dark matter drawn together • Process was “bottom-up”: small came together to make large
(More in-depth explanations follow.)
9 Modeling such collisions on a computer replicates observations.
• Summarize the evidence supporting elliptical galaxies formed from collisions and mergers of spiral galaxies. http://burro.astr.cwru.edu/SSAnims/ CartwheelEvol.mpg Observations Cartwheel Computer Simulation Galaxy
• Summarize the evidence supporting elliptical galaxies formed from collisions and mergers of spiral galaxies. Ellipticals most likely have formed from mergers
• Summarize the evidence supporting elliptical galaxies formed from collisions and mergers of spiral galaxies. 12 PLUS The farther away we look - the farther back in time - there are more spiral galaxies than elliptical galaxies; farthest galaxies - those that LOOK the youngest - all seem to be precursors of spiral galaxies.
Today Formation of Group of Galaxies
Formation of Filaments Coma Cluster ! Primordial fluctuations in density existed ! Gas and dark matter drawn together ! Process was “bottom-up”- small came together to make large 14 Collisions and subsequent mergers may explain why elliptical galaxies tend to be found where galaxies are closer together
• Summarize the evidence supporting elliptical galaxies formed from collisions and mergers of spiral galaxies. 15 Formation of Structure: The First Galaxies
•
First galaxy consisted of first system of stars that were gravitationally bound in a dark matter halo. We test our models using observations in the infrared part of the spectrum. (Why are IR observations required?) Formation of Structure: Small Galaxies
▪ Use Hubble Space Telescope to observe small galaxies in early universe.
• ▪ At least 100 of these small galaxies would be needed to build up a galaxy like the Milky Way.
• Summarize what is meant by the “bottom-up” or hierarchical process for galaxy formation. Formation of Structure: Galaxies Evolve
▪ Galaxies evolved hierarchically, with smaller fragments merging to form larger objects.
• ▪ Computer simulations of mergers can adequately reproduce the larger galaxies like our Milky Way.
• Summarize what is meant by the “bottom-up” or hierarchical process for galaxy formation. Galaxy Evolution
•
▪ Comparison of the Hubble classification of galaxies today with galaxies throughout the history of the universe. ▪ These images are evidence for hierarchical merging. Hierarchical Sales Model Learning goals: be able to …. • Summarize the evidence supporting elliptical galaxies formed from collisions and mergers of spiral galaxies images of collisions and mergers - observational evidence that can be supported by physics and computer models. • Summarize what is meant by the “bottom- up” (hierarchical) process for galaxy formation.
small structures that combined to form larger structures HAND IN THE Hubble Deep Field PARTICIPATION ACTIVITY - PAGES 137 - 140 - AS YOU LEAVE.
PLEASE WRITE IN BOTH SECTION LETTERS OR TA’S NAME!
GO DAWGS!