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Activity: Identifying Elements in Supernova
Remnants
Days Needed 1 Class period
Grade level 9 - 12
Objectives
Using X-ray line data, the students will identify elements
contained in supernova remnants. Students will compare and contrast
Supernova Remnant Spectral Data from different X-ray observatories.
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Science and Math Standards
| NCTM |
NSES |
Content Standard 1:
- Mathematics as Problem Solving |
Content Standard A:
- Abilities necessary to do scientific inquiry
- Understandings about scientific inquiry |
Content Standard 4:
- Mathematical Connections.
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Content Standard B:
- Structure of Atoms
- Interactions of energy and matter |
Content Standard 8
- Geometry from an Algebraic Perspective |
Content Standard G:
- Nature of Scientific Knowledge |
Prerequisites
Math Students should have some pre-algebra, and be able
to identify patterns and interpret graphs
Science Students should have an understanding of spectra
and how they are represented, an understanding of how atoms produce
spectral lines. Students should understand how elements are produced and
heated in supernova remnants.
Introduction
In groups of 2 or more, the students will be given several X-ray spectra
from the ASCA X-ray satellite and will be asked to determine what
elements
are present using a chart listing elements and the energies of their
emission lines. Following a class discussion of their results, they will
then be given ASTRO-E spectra of the same sources and asked to determine
which elements are present. (There will be much more accuracy with
ASTRO-E.) Finally, they will be given spectra from Constellation-X and
asked to determine what elements are present. (There will be even better
resolution with Constellation-X). Compare and contrast their findings as
a
class. |
Exploration
Materials
- Simulated ASCA, Astro-E and Constellation-X spectra of Tycho supernova
remnant (download Microsoft Word documents from below and print out)
- Chart of X-ray lines corresponding to elements (print out student
handout)
Simulated Supernova Remnant Spectra
Hand out the Student Worksheet to the class.
Student Worksheet.
Have the class do the activity and answer the questions on the worksheet.
The teacher may collect and grade them.
Extension - Under Development!
The empty space in our Universe is not actually empty. It is
filled with gas. As X-rays from a source, such as a supernova remnant,
travel long distances to reach our X-ray observatories, they interact with
this gas and can be absorbed by it. The more gas between the satellite and
the remnant, the more the spectrum will be affected by this absorption.
X-rays with the lowest energies are affected most strongly. The remnant
N103B/Sheet 3 is found in a nearby galaxy called the Large Magellanic
Cloud
(150,000 light years away). Use a Venn Diagram to compare and contrast its
spectrum with the supernova remnant spectrum of Tycho/ Sheet 2 (7,000
light
years away). Identify the emission lines in each spectrum in the same way
as you identified the lines in the simulated spectra of Tycho's supernova
remnant. Also think about the external conditions that could have caused
the similarities and differences in these two remnants' X-ray spectra.
Two X-ray satellite telescopes were sent out into space about 1 million
kilometers above Earth to observe the supernova remnants Tycho and W49B.
The telescopes obtained the Tycho spectra below (download and print the
MSWord document tycho-w49b-compare.doc) as well as W49B spectra. In one
paragraph, tell the meaning of emission lines, the difference between the
emission lines, and explain why there would exist apparent difference in
these lines. Contrast the Tycho emission lines. Contrast the W49B emission
lines.
Tycho and W49b supernova remnant
X-ray spectra - Under Development!
Evaluation
Formative assessment and observation should be evident throughout the
lesson. The worksheet, final questions during closure or a future quiz may
serve as summative assessment.
Closure
Direct students to write for ten minutes in their journals summarizing the
lab and all procedures in this lesson. Encourage students to then share
their findings and what they might have written in their journals.
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