Foundations of Astronomy (MindTap Course List)
14th Edition
ISBN: 9781337399920
Author: Michael A. Seeds, Dana Backman
Publisher: Cengage Learning
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Chapter 10, Problem 4P
To determine
The fraction of photons survived in cloud.
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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
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A cloud of mean number density n ~ 3000 cm-3 and radius 3 pc has an ionising
source with luminosity at 13.6 eV of L13.6eV = 2.18 x 109 erg s- at the centre.
(a) What is the size of the HII region in pe? [og = 2 x 10-13 cms-].
%3D
(b) What assumptions are involved in part
a)
(c) Discuss why the HII region will drive a shock into the rest of the cloud, and
calculate the post-shock density.
(d) Show why this HII region will destroy the cloud.
Chapter 10 Solutions
Foundations of Astronomy (MindTap Course List)
Ch. 10 - Prob. 1RQCh. 10 - Prob. 2RQCh. 10 - Prob. 3RQCh. 10 - Prob. 4RQCh. 10 - Prob. 5RQCh. 10 - Prob. 6RQCh. 10 - Prob. 7RQCh. 10 - Prob. 8RQCh. 10 - Prob. 9RQCh. 10 - Prob. 10RQ
Ch. 10 - Prob. 11RQCh. 10 - Prob. 12RQCh. 10 - Prob. 13RQCh. 10 - Why is the ISM transparent at near-infrared and...Ch. 10 - Prob. 15RQCh. 10 - Prob. 16RQCh. 10 - Prob. 17RQCh. 10 - Prob. 18RQCh. 10 - Prob. 19RQCh. 10 - Prob. 20RQCh. 10 - Prob. 21RQCh. 10 - Name two processes (or objects) that remove...Ch. 10 - Prob. 23RQCh. 10 - Prob. 24RQCh. 10 - Prob. 25RQCh. 10 - Prob. 1PCh. 10 - Prob. 2PCh. 10 - Prob. 3PCh. 10 - Prob. 4PCh. 10 - The number density of air in a childs balloon is...Ch. 10 - Calculate the frequency in megahertz (MHz) of the...Ch. 10 - Prob. 7PCh. 10 - Prob. 8PCh. 10 - Prob. 9PCh. 10 - Prob. 10PCh. 10 - Prob. 1SOPCh. 10 - Prob. 2SOPCh. 10 - Prob. 1LTLCh. 10 - Prob. 2LTLCh. 10 - Prob. 3LTLCh. 10 - Prob. 4LTLCh. 10 - Prob. 5LTL
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- A)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 calculation . B) The Mid-infared Instrument (MIRI , camera and spectrograph ) on the James Webb Space Telescope operates in the band 5-28 µm . For 58 Eridani , approximatley 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 calcultation . Describe breifly two or three other factors which play a role in determining the sensetivitu of an instrument such as MIRI ?arrow_forwardQuestion 2: apparent magnitude my 1 = 305.9, b = −44.9 and is d=4.5 kpc from the Sun. a.) The integrated light from the Milky Way globular cluster NGC 104 has an 4.03 mag and absolute magnitude My -9.52 mag. It is located at b.) = = Estimate the amount of extinction between the Sun and 47 Tucanae in magnitudes. What does this value of extinction mean for the amount of attenuation by dust between Earth and NGC 104?.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
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