Astronomy
1st Edition
ISBN: 9781938168284
Author: Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher: OpenStax
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 27, Problem 25E
Large redshifts move the positions of spectral lines to longer wavelengths and change what can be observed from the ground. For example, suppose a quasar has a redshift of
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A space based observatory collects light emitted by a given galaxy. The light was initially emitted with a frequency of 600*10^12Hz but the detected signal is red shifted by 40*10^12Hz
How fast is the galaxy moving and in what direction?
Show the algebraic form of any equation(s) that you apply and report your calculation in the correct units and with the correct number of significant figures.
Suppose a star 1000 times brighter than our Sun (that is, emitting 1000 times the power) suddenly goes supernova. Using data from Table: (a) By what factor does its power output increase? (b) How many times brighter than our entire Milky Way galaxy is the supernova? (c) Based on your answers, discuss whether it should be possible to observe supernovas in distant galaxies. Note that there are on the order of 1011 observable galaxies, the average brightness of which is somewhat less than our own galaxy.
Problem 2: Black hole – the ultimate blackbody
A black hole emits blackbody radiation called Hawking radiation. A black hole with mass
M has a total energy of Mc², a surface area of 167G²M² /c*, and a temperature of
hc³/167²KGM.
a) Estimate the typical wavelength of the Hawking radiation emitted by a 1 solar
mass black hole (2 × 103ºkg). Compare your answer to the size of the black hole.
b) Calculate the total power radiated by a one-solar mass black hole.
c) Imagine a black hole in empty space, where it emits radiation but absorbs nothing.
As it loses energy, its mass must decrease; one could say "evaporates". Derive a
differential equation for the mass as a function of time, and solve to obtain an
expression for the lifetime of a black hole in terms of its mass.
Chapter 27 Solutions
Astronomy
Ch. 27 - Describe some differences between quasars and...Ch. 27 - Describe the arguments supporting the idea that...Ch. 27 - In what ways are active galaxies like quasars but...Ch. 27 - Why could the concentration of matter at the...Ch. 27 - Describe the process by which the action of a...Ch. 27 - Describe the observations that convinced...Ch. 27 - Why do astronomers believe that quasars represent...Ch. 27 - Why were quasars and active galaxies not initially...Ch. 27 - What do we now understand to be the primary...Ch. 27 - What is the typical structure we observe in a...
Ch. 27 - What evidence do we have that the luminous central...Ch. 27 - Suppose you observe a star-like object in the sky....Ch. 27 - Why don’t any of the methods for establishing...Ch. 27 - One of the early hypotheses to explain the high...Ch. 27 - A friend of yours who has watched many Star Trek...Ch. 27 - Could the Milky Way ever become an active galaxy?...Ch. 27 - Why are quasars generally so much more luminous...Ch. 27 - Suppose we detect a powerful radio source with a...Ch. 27 - A friend tries to convince you that she can easily...Ch. 27 - Show that no matter how big a redshift (z) we...Ch. 27 - If a quasar has a redshift of 3.3, at what...Ch. 27 - If a quasar is moving away from us at v/c=0.8 ,...Ch. 27 - In the chapter, we discussed that the largest...Ch. 27 - Rapid variability in quasars indicates that the...Ch. 27 - Large redshifts move the positions of spectral...Ch. 27 - Once again in this chapter, we see the use of...Ch. 27 - In the Check Your Learning section of Example...Ch. 27 - In the Check Your Learning section of Example...Ch. 27 - The quasar that appears the brightest in our sky,...
Additional Science Textbook Solutions
Find more solutions based on key concepts
Consider the following debate between two students regarding the energy given off by the Sun.
Student 1: I thin...
Lecture- Tutorials for Introductory Astronomy
Centrifuges are widely used in biology and medicine to separate cells and other particles from liquid suspensio...
Essential University Physics: Volume 1 (3rd Edition)
The enthalpy of combustion of a gallon (3.8 liters) of gasoline is about 31,000 kcal. The enthalpy of combustio...
An Introduction to Thermal Physics
What is the role of “loose” electrons in heat conductors?
Conceptual Physics (12th Edition)
3. What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in th...
The Cosmic Perspective
11. A ball thrown horizontally at 25 m/s travels a horizontal distance of 50 m before hitting the ground. From...
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- In the mass function f(Ma, M) = MB/(1+ Ma/MB)² sin°i = M/(Ma + Mb) sin°i it gives us a lower limit on the mass of the unseen component of a single-lined spectroscopic binary. Why is the limit is on the unseen component rather than the component that we see?arrow_forwardOne of the strongest emission lines observed from distant galaxies comes from hydrogen and has a wavelength of 122 nm (in the ultraviolet region). How fast must a galaxy be moving away from us in order for that line to be observed in the visible region at 366 nm?arrow_forwardThe farthest objects in our Universe discovered by modern astronomers are so distant that light emitted by them takes billions of years to reach the Earth. These objects (known as quasars) have many puzzling features, which have not yet been satisfactorily explained. What is the distance in km of a quasar from which light takes 3.0 billion years to reach us ?arrow_forward
- In the Check Your Learning section of Example 27.1, you were told that several lines of hydrogen absorption in the visible spectrum have rest wavelengths of 410 nm, 434 nm, 486 nm, and 656 nm. In a spectrum of a distant galaxy, these same lines are observed to have wavelengths of 492 nm, 521 nm, 583 nm, and 787 nm, respectively. The example demonstrated that z=0.20 for the 410 nm line. Show that you will obtain the same redshift regardless of which absorption line you measure.arrow_forwardA gamma ray burst delivers approximately 1.0 X10-6 joules/m2 to a detector on an orbiting space telescope. Assuming that the red shift indicates that the source is 5 X109 light years away (1 yr =3.16X107 seconds) and that the energy at the detector has been corrected for the redshift, what is the energy output of the source and how does it compare to the rest energy of the Sun. The speed of light is 3.0 X 108 m/sec. A year is 3.16 X 107 sec. The mass of the Sun is 2 X 1030 kg. Rest mass energy is E=mc2. The surface area of a sphere is 4πr2. Answer choices: 1.2 X1045joules and 0.7 % 8 X 1047 joules and 100% 5 X 1046 joules and 8% 2.8 X 1046 joules and 16%arrow_forwardThe geometry of spacetime in the Universe on large scales is determined by the mean energy density of the matter in the Universe, ρ. The critical density of the Universe is denoted by ρ0 and can be used to define the parameter Ω0 = ρ/ρ0. Describe the geometry of space when: (i) Ω0 < 1; (ii) Ω0 = 1; (iii) Ω0 > 1. Explain how measurements of the angular sizes of the hot- and cold-spots in the CMB projected on the sky can inform us about the geometry of spacetime in our Universe. What do measurements of these angular sizes by the WMAP and PLANCK satellites tell us about the value of Ω0?arrow_forward
- A gamma ray burst delivers approximately 5.0 X10-6 joules/m2 to a detector on an orbiting space telescope. Assuming that the red shift indicates that the source is 5 X109 light years away (1 yr =3.16X107 seconds) and that the energy at the detector has been corrected for the redshift, what is the energy output of the source in units of 1047 joules and how does it compare to the rest energy of the Sun. The speed of light is 3.0 X 108 m/sec. A year is 3.16 X 107 sec. The mass of the Sun is 2 X 1030 kg. Rest mass energy is E=mc2. The surface area of a sphere is 4ππr2. Group of answer choices 1.9 and 8% 1.41 and 78% 80 and 100% 0.12 and 0.7%arrow_forwardThe rest-frame (natural) Wavelength of the H-a line of hydrogen is 656.3 nm. In the spectrum of light from a galaxy we observe, it is shifted to 763.8 nm. Calculate the reccession speed of the galaxy in m/s.arrow_forwardThe redshift measurements of spectra from magnesium and iron are important in understanding distant galaxies. What are the Kα and Lα wavelengths for magnesium and iron?arrow_forward
- Consider a spherical blackbody of constant temperature and mass M whose surface lies at radial coordinater = R. An observer located at the surface of the sphere and a distant observer both measure the blackbody radiation given off by the sphere. If the observer at the surface of the sphere measures the luminosity of the blackbody to be L, use the gravitational time dilation formula, to show that the observer at infinity measures. 2GM L̟ = L] 1- Rc?arrow_forwardThe peak intensity of the CMBR occurs at a wavelength of 1.1 mm. (a) What is the energy in eV of a 1.1-mm photon? (b) There are approximately 109 photons for each massive particle in deep space. Calculate the energy of 109 such photons. (c) If the average massive particle in space has a mass half that of a proton, what energy would be created byconverting its mass to energy? (d) Does this imply that space is “matter dominated”? Explain briefly.arrow_forwardP2 X The image to the left is a Feynman diagram with time increasing upward. P1 (a) If p1 is an electron and X is a W+ what must p2 be? Why? (b) If p1 is a μ+ and p2 is a different flavor of lepton, what must p2 be? Why? (c) In the last question, what must X be? Why? (d) If p1 and p2 are both electron neutrinos, what must X be? Why? (e) If p1 and p2 are both the same flavor of charged lepton, what might X be? (There are two possibilities.) Why?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
