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
Videos
Question
Chapter 6, Problem 42Q
To determine
The type of spectral line, the astronomers were looking for, while searching for ionized oxygen gas surrounding the Milky Way Galaxy.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
5. The two images below show a portion of the Trifid Nebula. The image on the left was
made with visible light, while the image on the right (shown to the same scale) is an infrared
image from the Spitzer Space Telescope. Explain why the dark streaks in the visible-light
image appear bright in the infrared image.
(a)
Reflection nebula,
Dust lanes
Emission nebula.
R
I
10 pc
www
V U X G
(b)
wwwwww
R
V
U X G
You record the spectrum of a distant star using a telescope on the ground on Earth. Upon
analysing the spectrum, you discover absorption lines spaced at intervals typical of oxygen
atoms. Which of the following are possible interpretations of this evidence? Select all that
apply.
The width of the spectral lines gives the diameter of the star
The star is likely orbited by habitable planets with breathable atmospheres.
The height of the spectral lines above the star's general blackbody spectral curve tells us how much
oxygen is in the star
The atmosphere of Earth contains oxygen
The red or blueshift of the set of lines can tell us the speed of the star's motion toward or away from us
Cas A SNR North Lobe
Chandra ACIS image
(M. Stage)
region of spectrum->
10*
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
1
0.1
Cas A Ms Spectrum from 4362.5 4458.5, region size 0.964324 sq. arcsec
Silicon line
werden der
5
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 0.6599 nm, how fast is the gas moving?
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
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
- Background: Design and completely analyze an optical system to measure how fast the Sun is spinning,based on the Doppler shift between the west side of the sun (always turning toward us atvelocity v1) and the east side (turning away from us, also at velocity v1). It turns out the Sun hasvery sharp emission lines at a wavelength of λ = 630.0 nm. You may ignore Earth’s rotation andatmosphere.You’ll need at least 2 parts in your optical system. First, you’ll need to gather (maybe focus,maybe magnify?) the light from only the outer edge of the sun—no more than 5% of itsdiameter as seen from Earth. Be sure your system blocks out the rest of the sun when taking ameasurement of one side or the other. Second, you’ll need to very precisely and accuratelyseparate the sun’s spectrum into different wavelengths so you can measure the difference inwavelength caused by the Doppler shifts. You can use any combination of any optical elementswe have discussed in class: lenses, mirrors, pinholes,…arrow_forwardCas 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?arrow_forwardYou observe an object’s spectrum and you find that it has a flat spectrum in lambda: its flux density is equal to flambda=2.0E-15 erg cm-2 s-1 A-1 at all wavelengths across the visible spectrum. What is the frequency (in Hz) corresponding to wavelength 4000 Angstroms, and wavelength 8000 Angstroms? What is the flux density fnu of this object at each of those two frequencies, in units of erg cm-2 s-1 Hz-1?arrow_forward
- Why is it difficult to observe at infrared wavelengths? What do astronomers do to address this difficulty?arrow_forwardStar X has lines of ionized helium in its spectrum, and star Y has bands of titanium oxide. Which is hotter? Why? The spectrum of star Z shows lines of ionized helium and also molecular bands of titanium oxide. What is strange about this spectrum? Can you suggest an explanation?arrow_forwarda) The star 58 Eridani is a feint but naked-eye star similar to the Sun. Suppose that you are observing this star in the night sky without a telescope. Ignoring any interstellar extinction or atmospheric absorption, approximately how many photons per second arrive at your retina? Show all steps in your calculation. Look up any required information about the star using Wikipedia. Use sensible approximations so your calculation is straightforward. For example you could consider only the region of the spectrum where the photon flux peaks. b) The Mid-Infrared Instrument (MIRI, camera and spectrograph) on the James Webb Space Telescope operates in the band 5 – 28 µm. For 58 Eridani, approximately how many photons per second can be used by this instrument? Assume that MIRI takes all the photons from the full JWST mirror. Show all steps in your calculation. Describe briefly two or three other factors which play a role in determining the sensitivity of an instrument such as MIRI?arrow_forward
- You have a radio telescope that you are designing to observe the fine details of the ring of hydrogen around Jupiter (yes, Jupiter does have rings, but not as pretty as Saturn.) Jupiter is about 5.93E8 km from Earth. If you are trying to observe gas structures the size of a small town (about 1.0 km across) and the wavelength of hydrogen alpha is 656.28 nm, then what is the minimum diameter that you would need to have for your telescope to resolve the needed details to Rayleigh criterion?arrow_forwardThe spectrum of a typical star shows absorption lines at different wavelengths than their laboratory values. If the observed wavelength is greater than its laboratory value of 656.3 nm, one can conclude that ... A. The separation between Earth and the star is decreasing. B. The separation between Earth and the star is increasing. O C. The separation between Earth and the star is unchanging D. No conclusion is possible.arrow_forwardYou are the leader of the international Event Horizon Telescope, a collaboration of radio astronomers who want to take a picture of the black hole at the center of the Milky Way (Sag. A*). That black hole has a mass of about 4.1 million solar masses and is about 8 kpc away. If you are observing with a radio wavelength of about 1 mm, what effective diameter of your radio interferometric array is needed in order to just resolve the diameter of the Sag. A* black hole event horizon. (Assume the black hole is non-spinning, so its diameter is twice the event horizon radius.) Express your answer as a multiple of the Earth's radius. [Hint: you will need to recall and combine three formulas introduced throughout this course, including one about how big a black hole is, one about the criterion for resolving objects, and another that relates distance, sizes, and angles.] There really is an Event Horizon Telescope, and they are responsible for the first image of a black hole in the galaxy M87…arrow_forward
- Imagine that you are observing a star and you find the wavelength of peak emission for the star to be 400 nm. What would the wavelength of peak emission be for a new star that has a surface temperature that is a quarter of the original star? Using the same pair of stars from the first question, how does the luminosity (the energy output) of each star compare if we assume that both stars are the same size? (Please provide a specific factor or proportion) What type of radiation/light (from the electromagnetic spectrum) is each star emitting? Now imagine that we determine that the wavelength of peak emission of the original star was determined to be bluer than it should be based on other observations. Would this indicate that the star is moving towards us or away from us relatively speaking through space? (Hint: think of the Doppler effect)arrow_forward1 Solar constant, Sun, and the 10 pc distance! The luminosity of Sun is + 4- 1026 W - 4- 1033ergs-1, The Sun is located at a distance of m from the Earth. The Earth receives a radiant flux (above its atmosphere) of F = 1365W m- 2, also known as the solar constant. What would have been the Solar contact if the Sun was at a distance of 10 pc ? 1AU 1 1.5-+ 1011arrow_forwardIn the graph below, the yellow region shows the AM 1.5 solar spectrum. The area indicated by the blue area represents the AM 1.0 spectrum. The boundaries of the AM 1.0 spectrum; When λ = between 250nm and 1000nm Pλ = 1x109Wm^(-2) m^(-1) When λ = between 1000nm and 2000nm Pλ = 0.25x109W m^(-2) m^(-1) In that case; a-) Find the radiation intensity (I) and photon flux () for AM 1.0. b-) If the radiation intensity in the option a comes to the silicon solar cell with a band gap of 1.12eV, how much will the photo-current be produced?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Stars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Stars and Galaxies
Physics
ISBN:9781305120785
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Convex and Concave Lenses; Author: Manocha Academy;https://www.youtube.com/watch?v=CJ6aB5ULqa0;License: Standard YouTube License, CC-BY