Modern Physics for Scientists and Engineers
4th Edition
ISBN: 9781133103721
Author: Stephen T. Thornton, Andrew Rex
Publisher: Cengage Learning
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Chapter 2, Problem 102P
Quasars are among the most distant objects in the universe and are moving away from us at very high speeds, as discussed in Chapter 16. Astrophysicists use the redshift parameter z to determine the redshift of such rapidly moving objects. The parameter z is determined by observing a wavelength λ′ of a known spectral line of wavelength λsource on Earth; z = Δλ/λsource = (λ′ − λsource) /λsource. Find the speed of two quasars having z values of 1.9 and 4.9.
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Hubble Distances
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Δ
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Astro 001 Fall 2022
Problem 02. How much smaller was the universe when this light was emitted?
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of the Hubble constant is Ho = 71 (km/s)/Mpc.
Problem 03. What is the distance in Mpc and ly to the galaxy measured in problem 01?
1 pc = 3.26 ly.
The bright radio galaxy, 3c84, is observed to be moving away from the Earth at such high speed that the emitted blue 434-nm Hγ line of hydrogen is Doppler-shifted to 442 nm.
Edwin Hubble discovered that all objects outside the local group of galaxies are moving away from us, with speeds v proportional to their distances R. Hubble's law is expressed as v = HR, where the Hubble constant has the approximate value
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The spectral lines of various elements are detected in light from a galaxy in the constellation Ursa Major. An ultraviolet line from singly ionized calcium (lS = 393 nm) is observed at wavelength l0 = 414 nm, redshifted into the visible portion of the spectrum. At what speed is this galaxy receding from us?
Chapter 2 Solutions
Modern Physics for Scientists and Engineers
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