21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
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Chapter 6, Problem 41QP
To determine
The angular resolution on looking at interstellar molecules using space VLBI.
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There are several spectral features that can be used to characterise galax-
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For the Hydrogen-a emission, the spectrograph on the FET just gives
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100 km s¹. Calculate the ruling density necessary to observe the Hydrogen-
ß emission line at the same resolution, if the observations are taken in first
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What is the ratio of the angular resolution limit of Keck to the angular resolution limit of HST? (Assume they are both observing at the same wavelength.)
[Compute the relevant ratio Keck/HST, express as a decimal, and enter below.]
HST orbits at an altitude of 559 km above the Earth's surface. Assume its orbit is circular.
Compute its orbital period in hours.
Compute its orbital speed (in km/s).
A cloud of gas has a temperature of 5,000 K.
Estimate the width of the hydrogen H-alpha line with an intrinsic wavelength λ = 656 nm.
(Note: the typical velocity of hydrogen atoms in a gas with temperature T is about (kT/mH)1/2, where k is Boltzmann constant and mH is the mass of a hydrogen atom, which is approximately the mass of a proton).
Chapter 6 Solutions
21st Century Astronomy
Ch. 6.1 - Prob. 6.1ACYUCh. 6.1 - Prob. 6.1BCYUCh. 6.2 - Prob. 6.2CYUCh. 6.3 - Prob. 6.3CYUCh. 6.4 - Prob. 6.4CYUCh. 6.5 - Prob. 6.5CYUCh. 6 - Prob. 1QPCh. 6 - Prob. 2QPCh. 6 - Prob. 3QPCh. 6 - Prob. 4QP
Ch. 6 - Prob. 5QPCh. 6 - Prob. 6QPCh. 6 - Prob. 7QPCh. 6 - Prob. 8QPCh. 6 - Prob. 9QPCh. 6 - Prob. 10QPCh. 6 - Prob. 11QPCh. 6 - Prob. 12QPCh. 6 - Prob. 13QPCh. 6 - Prob. 14QPCh. 6 - Prob. 15QPCh. 6 - Prob. 16QPCh. 6 - Prob. 17QPCh. 6 - Prob. 18QPCh. 6 - Prob. 19QPCh. 6 - Prob. 20QPCh. 6 - Prob. 21QPCh. 6 - Prob. 22QPCh. 6 - Prob. 23QPCh. 6 - Prob. 24QPCh. 6 - Prob. 25QPCh. 6 - Prob. 26QPCh. 6 - Prob. 27QPCh. 6 - Prob. 28QPCh. 6 - Prob. 29QPCh. 6 - Prob. 30QPCh. 6 - Prob. 31QPCh. 6 - Prob. 32QPCh. 6 - Prob. 33QPCh. 6 - Prob. 34QPCh. 6 - Prob. 35QPCh. 6 - Prob. 36QPCh. 6 - Prob. 37QPCh. 6 - Prob. 38QPCh. 6 - Prob. 39QPCh. 6 - Prob. 40QPCh. 6 - Prob. 41QPCh. 6 - Prob. 42QPCh. 6 - Prob. 43QPCh. 6 - Prob. 44QPCh. 6 - Prob. 45QP
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