Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
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Chapter 6, Problem 41Q
To determine
(a)
The wavelength of the emission.
The part of
To determine
(b)
The necessity of the using satellites to make the given observations.
To determine
(c)
The diameter of the primary mirror of SWAS.
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Cas A SNR North Lobe
Chandra ACIS image
(M. Stage)
region of spectrum->
104
km/s (be sure to convert your answer to kilometers!)
(Enter a positive value--if you get a negative answer ignore the minus sign.)
1000
100
Combine counts / Ang./ (0.964324 sq. arcsec)
10
0.1
Cas A Ms Spectrum from 4362.5 4458.5, region size 0.964324 sq. arcsec
Mapangh
5
Silicon line
10
20
Wavelength (Angstroms)
The speed of the material ejected in a supernova can be measured by using the Doppler shift of the X-ray emission lines in its spectrum. The images above show real X ray data of the Cassiopeia A supernova remnant and a spectrum extracted from that data--you can see several emission lines
including the silicon line near 6.6 angstroms (0.66 nm).
If the emission line created by silicon normally has a wavelength of 0.6648 nm (nanometers), but is measured in the spectrum to have a wavelength of 0.6611 nm, how fast is the gas moving?
What is the ratio of the angular resolution limit of Keck to the angular resolution limit of HST? (Assume they are both observing at the same wavelength.)
[Compute the relevant ratio Keck/HST, express as a decimal, and enter below.]
HST orbits at an altitude of 559 km above the Earth's surface. Assume its orbit is circular.
Compute its orbital period in hours.
Compute its orbital speed (in km/s).
(a) The colour temperature can be determined from two magnitudes corresponding to
two different wavelengths. Show that:
7000 K
Te
(B-V)+0.47
The wavelengths ofthe B and V bands are 440 nm and 548 nm, respectively, and we
assume that B=V for stars of the spectral class A0, the colour temperature of which
is about 15000 K°. (Take constant value - 0.73 and e-2.718).
Chapter 6 Solutions
Universe: Stars And Galaxies
Ch. 6 - Prob. 1QCh. 6 - Prob. 2QCh. 6 - Prob. 3QCh. 6 - Prob. 4QCh. 6 - Prob. 5QCh. 6 - Prob. 6QCh. 6 - Prob. 7QCh. 6 - Prob. 8QCh. 6 - Prob. 9QCh. 6 - Prob. 10Q
Ch. 6 - Prob. 11QCh. 6 - Prob. 12QCh. 6 - Prob. 13QCh. 6 - Prob. 14QCh. 6 - Prob. 15QCh. 6 - Prob. 16QCh. 6 - Prob. 17QCh. 6 - Prob. 18QCh. 6 - Prob. 19QCh. 6 - Prob. 20QCh. 6 - Prob. 21QCh. 6 - Prob. 22QCh. 6 - Prob. 23QCh. 6 - Prob. 24QCh. 6 - Prob. 25QCh. 6 - Prob. 26QCh. 6 - Prob. 27QCh. 6 - Prob. 28QCh. 6 - Prob. 29QCh. 6 - Prob. 30QCh. 6 - Prob. 31QCh. 6 - Prob. 32QCh. 6 - Prob. 33QCh. 6 - Prob. 34QCh. 6 - Prob. 35QCh. 6 - Prob. 36QCh. 6 - Prob. 37QCh. 6 - Prob. 38QCh. 6 - Prob. 39QCh. 6 - Prob. 40QCh. 6 - Prob. 41QCh. 6 - Prob. 42QCh. 6 - Prob. 43QCh. 6 - Prob. 44QCh. 6 - Prob. 45Q
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