21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
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Chapter 21, Problem 40QP
To determine
The peak wavelength, and temperature of the CMB spectrum, and compare the rough measurement with the accepted temperature measurement.
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1.2
1.0
0.8
0.6
Cosmic background
data from COBE
0.4
0.2
0.0
0.5
10
Wavelength A in mm
c)
Background (CMB) undertaken by the COBE satellite. Use this diagram to estimate the
current temperature of the CMB. Based on your estimate, what would the temperature of
the CMB have been at a redshift of z = 5000?
The left hand diagram above shows the results from observations of the Cosmic Microwave
Radiated Intensity per Unit Wavelength
(16° Watts/m per mm)
The Andromeda Galaxy, M31, is the closest large spiral galaxy to our Milky Way. When we look at its chemical spectrum, we see that its hydrogen alpha emission line (Hα) has an observed wavelength of λobs = 655 nm.-Calculate z, being careful with the sign.-How fast is it moving in km/s?-Is it redshifted or blueshifted? Is it moving towards or away from us?
answer to three significant figures.
The temperature of the CMB today is
T=2.725 K. Calculate the temperature of
the CMB at redshift z=2000. Choose the
option below that most closely matches
your answer.
Select one:
O a. 9759 K
O b. 3412 K
Ос.
5453 K.
O d. 5450K
Ое. 2000 К
Chapter 21 Solutions
21st Century Astronomy
Ch. 21.1 - Prob. 21.1CYUCh. 21.2 - Prob. 21.2CYUCh. 21.3 - Prob. 21.3ACYUCh. 21.3 - Prob. 21.3BCYUCh. 21.4 - Prob. 21.4CYUCh. 21 - Prob. 1QPCh. 21 - Prob. 2QPCh. 21 - Prob. 3QPCh. 21 - Prob. 4QPCh. 21 - Prob. 5QP
Ch. 21 - Prob. 6QPCh. 21 - Prob. 7QPCh. 21 - Prob. 8QPCh. 21 - Prob. 9QPCh. 21 - Prob. 10QPCh. 21 - Prob. 11QPCh. 21 - Prob. 12QPCh. 21 - Prob. 13QPCh. 21 - Prob. 14QPCh. 21 - Prob. 15QPCh. 21 - Prob. 16QPCh. 21 - Prob. 17QPCh. 21 - Prob. 18QPCh. 21 - Prob. 19QPCh. 21 - Prob. 20QPCh. 21 - Prob. 21QPCh. 21 - Prob. 23QPCh. 21 - Prob. 24QPCh. 21 - Prob. 25QPCh. 21 - Prob. 26QPCh. 21 - Prob. 27QPCh. 21 - Prob. 28QPCh. 21 - Prob. 29QPCh. 21 - Prob. 30QPCh. 21 - Prob. 31QPCh. 21 - Prob. 32QPCh. 21 - Prob. 33QPCh. 21 - Prob. 34QPCh. 21 - Prob. 35QPCh. 21 - Prob. 36QPCh. 21 - Prob. 37QPCh. 21 - Prob. 38QPCh. 21 - Prob. 39QPCh. 21 - Prob. 40QPCh. 21 - Prob. 41QPCh. 21 - Prob. 42QPCh. 21 - Prob. 43QPCh. 21 - Prob. 44QPCh. 21 - Prob. 45QP
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