Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 25, Problem 15Q
To determine
The wavelength at which we detect the Lyman alpha photons from the galaxy and in which
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Imagine that you are observing the light from a distant star that is located in a galaxy 100 million lightyears
away from you. By analysis of the starlight received, you are able to tell that the image we see is of a 10-
million-year-old star. You are also able to predict that the star will have a total lifetime of 50 million years, at
which point it will end in a catastrophic supernova.
a) How old does the star appear to be to us here on Earth now?
b) How long will it be before we receive the light from the supernova event?
c) Has the supernova already occurred? If so, when did it occur?
Assuming stars to behave as black bodies stefan-boltzmann law to show that the luminosity of a star is related to its surface temperature and size in the following way:
L = 4(3.14)R^2oT^4
where o= 5.67 ×10^-8 Wm^-2 K-4 is the stefan- boltzmann constant. Then use this expression together with the knowledge that the sun has a surface temperature of 5700k and radius 695 500km to calculate the luminosity of the Sun in units of Watts
Analyzing the spectrum of a distant galaxy, you discover evidence that a type la supernova is occurring in that galaxy. A type la supernova has a peak luminosity of about 1010 solar luminosities (1 solar luminosity = 3.8e26 Watts). Looking at an image of the galaxy, you estimate that here on earth
your telescope only sees a brightness of 8.45E-10 Watts/m². Using this information and the brightness equation, how distant is the galaxy in which the supernova is occurring? Give your answer in It yrs.
Chapter 25 Solutions
Universe: Stars And Galaxies
Ch. 25 - Prob. 1QCh. 25 - Prob. 2QCh. 25 - Prob. 3QCh. 25 - Prob. 4QCh. 25 - Prob. 5QCh. 25 - Prob. 6QCh. 25 - Prob. 7QCh. 25 - Prob. 8QCh. 25 - Prob. 9QCh. 25 - Prob. 10Q
Ch. 25 - Prob. 11QCh. 25 - Prob. 12QCh. 25 - Prob. 13QCh. 25 - Prob. 14QCh. 25 - Prob. 15QCh. 25 - Prob. 16QCh. 25 - Prob. 17QCh. 25 - Prob. 18QCh. 25 - Prob. 19QCh. 25 - Prob. 20QCh. 25 - Prob. 21QCh. 25 - Prob. 22QCh. 25 - Prob. 23QCh. 25 - Prob. 24QCh. 25 - Prob. 25QCh. 25 - Prob. 26QCh. 25 - Prob. 27QCh. 25 - Prob. 28QCh. 25 - Prob. 29QCh. 25 - Prob. 30QCh. 25 - Prob. 31QCh. 25 - Prob. 32QCh. 25 - Prob. 33QCh. 25 - Prob. 34QCh. 25 - Prob. 35QCh. 25 - Prob. 36QCh. 25 - Prob. 37QCh. 25 - Prob. 38QCh. 25 - Prob. 39QCh. 25 - Prob. 40QCh. 25 - Prob. 41QCh. 25 - Prob. 42QCh. 25 - Prob. 43QCh. 25 - Prob. 44QCh. 25 - Prob. 45QCh. 25 - Prob. 46QCh. 25 - Prob. 47QCh. 25 - Prob. 48QCh. 25 - Prob. 49QCh. 25 - Prob. 50QCh. 25 - Prob. 51QCh. 25 - Prob. 52QCh. 25 - Prob. 53QCh. 25 - Prob. 54QCh. 25 - Prob. 55Q
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
- The Andromeda Galaxy, M31, is the closest large spiral Galaxy to our Milky Way. When we lookat its chemical spectrum, we see that it's hydrogen alpha emission line has an observed wavelength of 655nm. a. Calculate z, being careful with the sign b. How fast is it moving in km/s c. Is it redshifted or blueshifted? Is it moving toward or away from us?arrow_forwardProblem 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.arrow_forwardThe Sun as seen from Earth has an apparent magnitude of -26 in the B-band.1. What would its apparent magnitude be as seen from Jupiter? (Jupiter is approximately 5.2 AU from theSun.)2. At a certain distance d from a Star A, its apparent brightness is f. If we were to travel at a relativisticvelocity to a point in space which is 5 times further away, how much fainter would the star appear to us?(i.e. what fraction of its original apparent brightness would it now appear to us?)arrow_forward
- What is the wavelength in micrometers of peak emission for a black body at 33.5°C? (c = 3.0 × 108 m/s, Wien displacement law constant is 2.9 × 10-3 m ∙ K, σ = 5.67 × 10-8 W/m2 ∙ K4). Please give your answer with one decimal place.arrow_forwardUse Wien's Law to calculate the peak wavelength of light coming from the Sun. Assume T=5800 K for the surface temperature of the Sun. Wein's displacement law says that the blackbody temperature and peak wavelength multiplied together give a constant of 0.29 cm-K. (K is degrees Kelvin). Convert the wavelength from part A into a frequency. The product of wavelength and frequency for electromagnetic radiation is a constant, the speed of light (c), 3 x 10^10 cm/s.arrow_forwardYou observe the H-alpha line of Hydrogen in a distant galaxy to have a wavelength of 754.4 nm. What is the radial velocity of the galaxy? Hint: The rest wavelength of H-alpha is 656 nm.arrow_forward
- What is the peak wavelength (in nm) of a neutron star's luminosity if its temperature is 106 K?arrow_forwardWhy would we not expect to detect X-rays from a disk of matter about an ordinary star?arrow_forwardIn 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_forward
- Would you expect to be able to detect an H II region in X-ray emission? Why or why not? (Hint: You might apply Wien’s law)arrow_forwardWhy is Hubble’s law considered one of the most important discoveries in the history of astronomy?arrow_forwardYou observe the H-alpha line of Hydrogen in a distant galaxy to have a wavelength of 754.4 nm. What is the radial velocity of the galaxy? Hint: The rest wavelength of H-alpha is 656 nm. I have to use the forumla mentioned in the photo I shared with this post.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Modern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Modern Physics
Physics
ISBN:9781111794378
Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher:Cengage Learning