21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 19, Problem 33QP
(a)
To determine
The redshift of that galaxy.
(b)
To determine
The recession velocity in kilometers per second.
(c)
To determine
The distance of the galaxy in megaparsecs.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
An astronomer observed the motions of some galaxies. Based on his observations, he made the following statements. Which one of them is most likely to be false? Take Hubble's constant to be 67 km/s/Mpc.
A. A galaxy observed to be moving away from us at a speed of 70 km/s is at a distance of about 1 Mpc from us.
B. A galaxy observed to be moving away from us at a speed of 700 km/s is at a distance of about 10 Mpc from us.
C. A galaxy observed to be moving away from us at a speed of 7000 km/s is at a distance of about 100 Mpc from us.
D. A galaxy observed to be moving away from us at a speed of 70000 km/s is at a distance of about 1 Gpc from us.
Is the answer D? Thank you!
What are the angular diameters of the following, as seen from Earth?
a. The Sun, with radius R = Rsun = 7x10^5 km.
b. Betelgeuse, with MV = -5.5 mag, mv = 0.8 mag, and R = 650Rsun.
c. The galaxy M31, with R = 30 kpc at a distance D = 0.7Mpc.
d. The Coma cluster of galaxies, with R = 3 Mpc at a distance D = 100 Mpc.
What happens when galaxies collide?
A. Star collisions will be rare but the shapes of the galaxies will be largely distorted.
B. The shapes of the galaxies will be largely distorted and many of the stars of one galaxy will collide with stars of the other galaxy.
C. The shapes of the galaxies will be distorted and many stars will collide with stars of the other galaxy, as well as with other stars in the same galaxy.
D. Star collisions will be rare and the two galaxies will just pass through each other without any changes.
Is the answer A? Thank you!
Chapter 19 Solutions
21st Century Astronomy
Ch. 19.1 - Prob. 19.1ACYUCh. 19.1 - Prob. 19.1BCYUCh. 19.2 - Prob. 19.2CYUCh. 19.3 - Prob. 19.3CYUCh. 19.4 - Prob. 19.4CYUCh. 19 - Prob. 1QPCh. 19 - Prob. 2QPCh. 19 - Prob. 3QPCh. 19 - Prob. 4QPCh. 19 - Prob. 5QP
Ch. 19 - Prob. 6QPCh. 19 - Prob. 7QPCh. 19 - Prob. 8QPCh. 19 - Prob. 9QPCh. 19 - Prob. 10QPCh. 19 - Prob. 11QPCh. 19 - Prob. 12QPCh. 19 - Prob. 13QPCh. 19 - Prob. 14QPCh. 19 - Prob. 15QPCh. 19 - Prob. 16QPCh. 19 - Prob. 17QPCh. 19 - Prob. 18QPCh. 19 - Prob. 19QPCh. 19 - Prob. 20QPCh. 19 - Prob. 21QPCh. 19 - Prob. 22QPCh. 19 - Prob. 23QPCh. 19 - Prob. 24QPCh. 19 - Prob. 25QPCh. 19 - Prob. 26QPCh. 19 - Prob. 27QPCh. 19 - Prob. 28QPCh. 19 - Prob. 29QPCh. 19 - Prob. 30QPCh. 19 - Prob. 31QPCh. 19 - Prob. 32QPCh. 19 - Prob. 33QPCh. 19 - Prob. 34QPCh. 19 - Prob. 35QPCh. 19 - Prob. 36QPCh. 19 - Prob. 37QPCh. 19 - Prob. 38QPCh. 19 - Prob. 39QPCh. 19 - Prob. 40QPCh. 19 - Prob. 41QPCh. 19 - Prob. 42QPCh. 19 - Prob. 43QPCh. 19 - Prob. 44QPCh. 19 - Prob. 45QP
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 supermassive black hole at the center of a galaxy has a mass of 6.5 billion solar masses. If we assume that it is a Schwarzschild black hole, what is the radius of this black hole? A. 18 light hours B. 20 light hours C. 16 light hours D. 14 light hours Is the answer A? S. radius = 3 x 6.5 x 109 x 9.26567-10 = 18.1 light hours Thanks!arrow_forwardAstronomers now think that there is a black hole with more than 4 milliion times the mass of our Sun at the center of our galaxy? Roughly how large would the event horizon of such a supermassive black hole be? a. the size of our moon b. about 4 light years across c. about 17 times the size of our sun d. about the size of an atom (so much mass really compresses the event horizon) e. this question can't be answered without knowing what kind of stars were swallowed by the black holearrow_forward1. If a star has a surface temperature of 3000 K but a luminosity 150 times greater than our Sun, what size is this star? Give your answer in units of the solar radius. 2. At what wavelengths do stars of surface temperates 20 000 K, 10 000 K, and 3000 K have their peak intensity? 3. If the Hα absorption line in the spectrum of a galaxy is observed at a wavelength of 6715 ˚A, at what speed is the galaxy moving away from us?arrow_forward
- 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_forwardWhat makes us think that the star system Cygnus X-1 contains a black hole? A, It emits X rays characteristic of an accretion disk, but the unseen star in the system is too massive to be a neutron star. B. No light is emitted from this star system, so it must contain a black hole. C. The fact that we see strong X-ray emission tells us that the system must contain a black hole. D.Cygnus X-1 is a powerful X-ray burster, so it must contain a black hole.arrow_forward2. A galaxy cluster has a galaxy behind it whose image we see as being smeared out and curved, with an angular radius of curvature on the sky of θE. The background galaxy is at redshift zgal and the cluster is at zclust. What is the mass of the cluster in solar masses? Give your response in scientific notation with one decimal place. (The Hubble constant is of course 70 km/s/Mpc, and you can assume the Hubble law for these low redshifts). Values: zgal = 0.11 zclust = 0.07 θE = 117.4 arcsecondsarrow_forward
- A. Estimate the surface gravity of a neutron star with R = 10 km and M = 2M. . B. Determine the density of such a neutron star in g/cm³. C. How much would a teaspoon (5 cm³) of this neutron star weigh on Earth? This material is known as neutronium. Give your answer in pounds. D. Which would be heavier: a teaspoon of neutronium weighed on Earth, or a teaspoon of water weighed on the surface of a neutron star?arrow_forward1. If a galaxy is 9.1 Mpc away from Earth and recedes at 511 km/s, what is H0 (in km/s/Mpc)? 2. What is the Hubble time (in yr)? 3. How old (in yr) would the universe be, assuming space-time is flat and the expansion of the universe has not been accelerating?arrow_forwardWhat type of galaxy is NCG 1317? a. E5 b. SBa c. S0 d. Saarrow_forward
- In a spiral galaxy, the orbital speeds of stars far from the galaxy's center distance from the center increases. as the A. increase B. decrease C. are approximately the same D. The answer changes depending on the galaxy.arrow_forwardRecall that Hubbleʹs law is written v = H0d, where v is the recession velocity of a galaxy located a distance d away from us, and H0 is Hubbleʹs constant. Suppose H0 = 80 km/s/Mpc. How fast would a galaxy located 800 megaparsecs distant be receding from us? A. 64 Mpc/s B. 64,000 km/s C. 0.1 times the speed of light D. 10 km/s E. 64 km/sarrow_forwardTrue or False: Dwarf elliptical galaxies and giant ellipticals probably formed in entirely different ways.a. Trueb. Falsearrow_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
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
General Relativity: The Curvature of Spacetime; Author: Professor Dave Explains;https://www.youtube.com/watch?v=R7V3koyL7Mc;License: Standard YouTube License, CC-BY