1. How Do We Know? Using the Electromagnetic Spectrum
To Understand the Universe
And the implications of
Fermi Space Telescope Data
on our understanding

2. How to start?
Introduce students to Epo and Alkina in the EPO Chronicles .
Have them follow their adventures and write about them in a journal for homework.

3. Catch a Ray
Talk about and explore characteristics of light energy

4. Light as Waves
Compare different wavelengths to different spring like things

5. How Do We Know
Scientists study how light and other energies interacts with different things.
From those observations they know that light, and any other kind of energy travels in waves.

6. How Do We Know
Scientists studied those waves and noticed that they had rules.
They noticed that in any one type of energy, the space between the top of one loop to the top of the next loop was always the same.
They called that space wavelength

7. How Do We Know
Scientist also noticed that every different kind of energy had a different wavelength
Because of this, scientist now had a way to tell different kinds of energy apart.

8. How Do We Know
Because each wavelength was exactly the same as the next, scientist discovered that each kind of energy moved a different amount of waves through a specific space in a specific time.
Because of this, scientist now discovered you could tell what kind of energy you had by counting the amount of waves that went by in a set amount of time. They called this measurement frequency.

9. What does the EMS tell us? (Electromagnetic Spectrum)
Transports energy
Electric and magnetic fields oscillate: that’s the “wave”
Moves at speed of light, 3 x 108 m/s
Wavelength, frequency, energy all related
Type of radiation (usually) depends on energy/temperature of object

10. How Do We Know?
When we organize light waves in this type of order, we call it the “Electromagnetic Spectrum” or EMS

11. How Do We Know
Radio waves are energy that has long wavelengths and small frequencies.
They are as big as buildings and as small as a human.
They are the kind of energy we attach radio signals to broadcast them.
Stars and gasses in space also emit radio waves

12. How Do We Know
Microwaves have a shorter wavelength, about the size of a honeybee.
Cell phones and microwave ovens produce microwaves
Gasses that are collapsing into stars in space also produce microwaves

13. How Do We Know
Infrared energy has an even shorter wavelength, about the size of the head of a pin.
They are easily absorbed into molecules, heating them up, like our french fries at MacDonald's
The dust between the stars also gives off infrared energy

14. How Do We Know
Visible light rays are even shorter, about the size of a protozoan.
Visible light is the kind of energy that bounces off of me, into your eyes, and allows you to see me.
Anything you can see with your eyes is in the visible light range

15. How Do We Know
Ultraviolet wavelengths are even smaller, about the size of a molecule. That makes their frequencies very high.
A lot of waves can fit in a space, so they have a lot of energy
The sun and other stars produce ultraviolet energy
Our skin is a detector of ultraviolet energy

16. How Do We Know
X-rays are even smaller than Ultraviolet waves, about the size of an atom
so they have even more energy than ultraviolet rays
Doctors use x-rays to look at your bones.
Hot gases in space also emit x-rays

17. How Do We Know
Gamma rays are even smaller than x-rays, about the size of a nucleus of an atom. They have even more energy.
Radioactive materials, and particle accelerators make gamma rays
The biggest producer of gamma rays is our universe

18. How Do We Know
We started to make telescopes that would detect different kinds of frequencies
Some telescopes can detect visual light energy
Some can detect X-ray energy
Some can detect radio energy
Putting all this information together helps us to understand what’s going on in our universe

19. To see gamma rays, X-rays, most UV and some IR you must go to space
Only
visible, radio and
some IR and UV gets through the air!
To see gamma rays, X-rays, most UV and some IR you must go to space

20. Hubble Space Telescope
How Do We Know?
Hubble Space Telescope
Is probably the most famous of Telescopes
Three cameras, two spectrographs, and fine guidance sensors
Produces high resolution images of astronomical objects
Its images are 10 times better than the best telescope on earth.
Takes pictures of small areas in great detail

21. How Do We Know? GALEX Space Telescope
Relatively small satellite. It is just about six feet tall and as wide as your outstretched arms.
The two mirrors of the GALEX telescope are just a half meter (20 inches) across
Acts like a digital camera that takes pictures in the ultraviolet range of light waves
Takes broad far away shots of the sky

22. How Do We Know? GALEX Space Telescope
Orbits the earth once every 98 minutes
Takes pictures that are 2 moons wide
Has special mirrors that curve the light.
Ordinary telescopes would get images that looked like comets from such a large scan of the sky. GALEX’s mirrors change that kind of image into a flat picture
In addition to visible light GALEX has detectors that can read ultra violet light

23. How Do We Know? GALEX Space Telescope
Hubble Telescope takes very detailed pictures of a very small section of the sky
GALEX takes very large pictures of very large pieces of the sky
It’s kind of like Hubble taking close up pictures and GALEX taking landscape picture

24. GALEX & Hubble Space Telescopes
How Do We Know?
GALEX & Hubble Space Telescopes
Working Together
Scientists take pictures from Hubble and Galax and compare and contrast the data from both telescopes
The analysis of these images and images from many more telescopes are the basis of what we know about the Universe today.

25. Size and Scale of the Universe
What We Know
Size and Scale of the Universe
Image courtesy of The Cosmic Perspective by Bennett, Donahue, Schneider, & Voit; Addison Wesley, 2002

26. M45 – The Pleiades Cluster
X-ray: T. Preibisch
Ultraviolet: MSX
Visible: AAO
Infrared: IRAS
Radio: NVSS

27. Multi-wavelength Crab Nebula
X-ray: Chandra
Ultraviolet: UIT
Visible: Palomar
Infrared: 2MASS
Radio: VLA

28. M51 – The Whirlpool Galaxy
X-ray: Chandra
Ultraviolet: GALEX
Visible: T. & D. Hallas
Infrared: ISO
Radio: VLA

30. Sample Universal Objects

31. How Big? Telescope 40 feet long, 12 meters Moon
2,000 miles across, 3,200 kilometers
Saturn
75,000 miles across, 121,000 kilometers
Sun
875,000 miles across, 1,408,000 kilometers
Pleiades
60 trillion miles across, 1 x 1014 Kilometers
Whirlpool Galaxy
600 thousand trillion miles across, 1 x 1018 Kilometers
Hubble Galaxies
600 thousand million trillion miles across, 1 x 1021 Kilometers

32. How Far? Telescope 350 miles above Earth’s surface, 560 kilometers
Moon
250,000 miles, 402,000 kilometers
Sun
93,000,000 miles, 1.5 x 108 kilometers
Saturn
120,000,000 miles, 1.3 x 109 kilometers (at its closest)
Pleiades
2,400 trillion miles, 4 x 1016 kilometers
Whirlpool Galaxy
200 million, trillion miles, 3 x 1020 kilometers
Hubble Galaxies
30 billion trillion miles, 5 x 1020 kilometers

33. How Old? Telescope A few years (launched in 1990) Pleiades
80 million years
Moon
4.5 Billion years
Saturn
Sun
Whirlpool Galaxy
13 billion years
Hubble Galaxies

34. Shields and Detectors Identify sources of EMS energies
Radio has AM & FM bands
Remote controls use infrared energy
Torch is black (UV) light and visible light

35. Shields and Detectors Your ears detect Radio waves
Digital cameras detect infrared waves
Your eyes detect visible light waves
UV Beads detect ultraviolet waves

36. Shields and Detectors Clear plastic Black plastic Aluminum foil
Copy paper
Cloth
Metal screen
Plastic screen
Wax paper
Baggie

37. Assessment You are a member of the EPO (Education and Public Outreach)
team with Epo and Alkina. They are busy exploring the universe
and ask you to cover a press conference for them.
Epo has given you data from a new event in 5 different spectrums.
You need to explain what the event is in a way that non scientists will understand. Use what you know about how the different energies react on earth to explain what is happening in the event. You may do this in any way you like, but remember your audience (the television camera men and the people that will be watching on CNN) are not scientists and do not understand how energies react as you do. You will get points based on how much and how clearly you use the data given to
explain the event.
You may use any format that you feel will help the public understand. Points will be granted for creativity and clarity of your message.
Students are required to prepare a NASA news conference where they can use any means possible to explain to the public what the images represent. They can use power point, models, written and oral presentations as long as they make their point.

38. For NASA Press Conference Performance Assessment
Assessment Rubric
For NASA Press Conference Performance Assessment
Category
25 points
20 points
10 points
Understanding
Comprehension
(possible 25 points)
Student is able to accurately answer all questions posed by classmates and instructor based on information from the unit.
Student is able to answer questions posed by classmates and instructor about the topic, but is not sure of the accuracy of his answers.
Student is not able to back answers to questions posed by classmates and instructor with information from the unit. Answers are garbled and/or confused.
Understanding content
(Possible 25 points)
The student can accurately identify at least 1 characteristic in all 5 pictures
The student can accurately identify at least 1 characteristic in 3 of the pictures provided
The student can accurately identify at least 1 characteristic in two of the pictures provided
Performance
(Possible
25 Points)
The student can accurately explain the significance of at least 1 characteristic in all 5 pictures.
The student can accurately explain the significance of at least 1 characteristic in 3 of the pictures provided.
The student can accurately explain the significance of at least 1 characteristic in 2 of the pictures provided.
(total possible points 25)
The student provides at least one example of the energy analyzed as it exists on earth.
(one example of x-ray energy, one example of ultraviolet energy, one example of visible light energy, one example of infrared energy, one example of radio energy)
The student provides at least one example of the energy analyzed as it exists on earth for three different energy sources.
The student provides at least one example of the energy analyzed as it exists on earth for two different energy sources.
Total Possible points
100

39. Fermi - Gamma Ray Large Area Space Telescope
Implications of Fermi Data on our understanding of the universe

40. Launch! The Fermi Observatory Was Loaded into the payload of a DELTA
Rocket

41. Cape Canaveral Air Station
Launch!
And launched from
Cape Canaveral Air Station
June 11, 2008
at 12:05 PM EDT

42. The Observatory Large Area Telescope -LAT
Gamma-ray Burst Monitor - GBM

43. GBM Collaboration National Space Science & Technology Center
University of Alabama
in Huntsville
NASA
Marshall Space Flight Center
Max-Planck-Institut für
extraterrestrische Physik

44. GBM Instrument Design: Major Components
Data Processing
Unit (DPU)
2 Bismuth Germanate (BGO)
Scintillation Detectors
12 Sodium Iodide (NaI)
Scintillation Detectors
Characteristics
5-inch diameter, 0.5-inch thick
One 5-inch diameter PMT per Det.
Placement to maximize FoV
Thin beryllium entrance window
Energy range: ~5 keV to 1 MeV
Major Purposes
Provide low-energy spectral coverage in the typical GRB energy regime over a wide FoV
Provide rough burst locations over a wide FoV
Characteristics
Analog data acquisition electronics for detector signals
CPU for data packaging/processing
Major Purposes
Central system for instrument command, control, data processing
Flexible burst trigger algorithm(s)
Automatic detector/PMT gain control
Compute on-board burst locations
Issue r/t burst alert messages
Characteristics
5-inch diameter, 5-inch thick
High-Z, high-density
Two 5-inch diameter PMTs per Det.
Energy range: ~150 keV to 30 MeV
Major Purpose
Provide high-energy spectral coverage to overlap LAT range over a wide FoV

45. LAT Collaboration France Italy Japan Sweden United States
CNRS/IN2P3, CEA/Saclay
Italy
INFN, ASI, INAF
Japan
Hiroshima University
ISAS/JAXA
RIKEN
Tokyo Institute of Technology
Sweden
Royal Institute of Technology (KTH)
Stockholm University
United States
Stanford University (SLAC and HEPL/Physics)
University of California at Santa Cruz - Santa Cruz Institute for Particle Physics
Goddard Space Flight Center
Naval Research Laboratory
Sonoma State University
Ohio State University
University of Washington
Principal Investigator:
Peter Michelson (Stanford University)
~270 Members
(~90 Affiliated Scientists, 37 Postdocs,
and 48 Graduate Students)
construction managed by
Stanford Linear Accelerator Center (SLAC), Stanford University

46. What Makes Fermi Special?
Fermi surveys the whole sky every three hours.
Taking advantage of the huge fields of view of the GBM and the LAT, Fermi is operated in a scanning mode that monitors the sky regularly. The reason this survey mode is important is that the gamma-ray sky is dynamic, showing changes on time scales ranging from milliseconds to years.

47. Large Area Telescope First Light!
The full gamma-ray sky projected onto a surface
The EGRET map was a compilation of
18 months of data.
This map represents just 4 days of Fermi data!
But it looks like the
Energetic Gamma Ray Experiment Telescope map. What’s new?

48. Many More Sources Expected
LAT 1st Catalog:
>9000 sources possible
The 271 sources in the third EGRET catalog involved considerable manual processing. The LAT analysis will rely much more heavily on automated processing.

49. What’s going on in the gamma-ray sky?
Milky Way – Gamma rays from powerful cosmic ray particles smashing into the tenuous gas between the stars.
Pulsars – rapidly spinning neutron stars with enormous magnetic and electric fields
Some gamma-ray pulsars took years for EGRET to see.
The LAT confirmed all the EGRET pulsars
in a matter of days and is now looking for more.

50. What is new in the gamma-ray sky?
Blazars – supermassive black holes with huge jets of particles and radiation pointed right at Earth.
PKS a blazar 10 billion light years away, never detected by EGRET, flared up overnight to become one of the brightest things in the gamma-ray sky.
3C LAT saw it flare up 5 times brighter than EGRET ever measured.

51. Finding Pulsars
The Pulsing Sky
Pulses at
tenth true
rate

52. Gamma Ray Bubble at the center of the Milky Way

53. Thunderstorms create antimatter!

54. The speed of energy

55. What Next for Fermi?
We have only scratched the surface of what the Fermi Gamma-ray Space Telescope can do.
The gamma-ray sky is changing every day, so there is always something new to learn about the extreme Universe.
Some results from both the GBM and the LAT are starting to be made public through the Fermi Science Support Center.
Fermi science teams are cooperating with many other missions and observatories to maximize the scientific return.
Follow the latest news at the Project Scientist’s blog,