Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
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Chapter 26, Problem 46Q
To determine
(a)
The mass of the neutrino.
To determine
(b)
The reason for the massive neutrinos to not be the dominant type of dark matter in the universe.
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Students have asked these similar questions
With a Hubble constant of 70 km/sec/Mpc, the critical density would be
1.4 g/cc.
9 × 10-27 kg/m3.
6.23 × 10-23 g/mole.
4 × 10-36 g/cc.
3 × 10-31 g/cc.
The mass of the neutrino plays an important role in the universe. Suppose the mass of
two neutrinos in the universe is 4.8×10-³5 kg and the current Hubble’s constant is
72 km/s/Mpc. The critical density of the universe is five times the average density of
the universe. Estimate the number of neutrons present per cubic meter in the universe.
(a) 2.1×10⁹
(b) 4.1×10²
(c) 1.1x10°
(d) 8.1×107
Consider a Schechter luminosity function of the form
where a = 0.9, ΦΣ
=
-0
(L)dL = D(+)
L
e-(L/Lx)dL,
L
0.012h3 Mpc3 and L
-
1010h Lo. Calculate the total number
density. Express the final answer in terms of h where h = Ho/(100 km s−¹Mpc¯¹) (Ho
is the Hubble constant).
Chapter 26 Solutions
Universe: Stars And Galaxies
Ch. 26 - Prob. 1QCh. 26 - Prob. 2QCh. 26 - Prob. 3QCh. 26 - Prob. 4QCh. 26 - Prob. 5QCh. 26 - Prob. 6QCh. 26 - Prob. 7QCh. 26 - Prob. 8QCh. 26 - Prob. 9QCh. 26 - Prob. 10Q
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