A galaxy at a distance of 25 Mpc has a recession velocity of 1875 km/sec. What is Hubble’s constant based on this one galaxy? Why is this not a good way to determine Hubble’s constant? Galaxy NGC 123 has a velocity away from us of 1,320 km/s and the Hubble Constant's value is 70 km/s/Mpc. How far away is the galaxy according to Hubble's Law?

A galaxy at a distance of 25 Mpc has a recession velocity of 1875 km/sec. What is Hubble’s constant based on this one galaxy? Why is this not a good way to determine Hubble’s constant? Galaxy NGC 123 has a velocity away from us of 1,320 km/s and the Hubble Constant's value is 70 km/s/Mpc. How far away is the galaxy according to Hubble's Law?

Foundations of Astronomy (MindTap Course List)

14th Edition

ISBN:9781337399920

Author:Michael A. Seeds, Dana Backman

Publisher:Michael A. Seeds, Dana Backman

Chapter16: Galaxies: Normal And Active

Section: Chapter Questions

Problem 2SOP: If the diameter of the Milky Way Galaxys visible disk, 80,000 ly, is represented in a model by a...

See similar textbooks

Similar questions

A Type la supernova explodes in a galaxy at a distance of 6.10×107 light-years from Earth. If astronomers detect the light from the supernova today, how many years T have passed since the supernova exploded? T= 2.07 x10 -5 years Given a Hubble constant of 74.3 km/s/Mpc, at what speed v is this galaxy moving away from Earth? v= km/s What is this galaxy's redshift? redshift:
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!
The figure below shows the spectra of two galaxies A and B. Please can i get help with this questions below: 1. Which of these galaxies has ongoing star formation? How can you tell?2. One of these galaxies has Hubble type E3 while the other is SBb. Which is which? What does the 3 inE3 tell you about the galaxy? What does the SB in SBb tell you about the galaxy?3. What effects would dust have on the two spectra?4. Which galaxy would you expect to have more far-infrared emission? Expl
Figure 2 shows the "rotation curve" of NGC 2742. It plots the “radial velocity (V)" (how fast material is moving either toward or away from us) that is measured for objects at different distances (R = radius") from the center of the galaxy. The center of the galaxy is at 0 kpc (kiloparsecs) with a speed of 9 km/sec away from us. (These velocities have been corrected for the observed tilt of the galaxy and represent true orbital velocities of the stars and gas.) 200 100 U4779 -100 As you can see, one side of the galaxy is moving with a negative velocity (spinning toward us), while the other side has a positive velocity (spinning away from us). Using Newton's gravity equation, we will be able to determine the gravitational mass of the entire galaxy and how the mass varies versus distance from the galaxy's center. -200 -8 8 -4 Radius (kpc) Read the following text carefully and follow the instructions: Select five radii spaced evenly from 0-10 kpc across the galaxy. Your selections should…
Are the galaxies red-shifting or blue-shifting? Explain. (You may find the big-bang theory helpful). Andromeda galaxy is currently approaching our galaxy with a radial velocity of 266 km/sec. How far is our galaxy from Andromeda? (Hubble’s constant, H, is 73 km/sec/MParsec). When can the two galaxies be anticipated to collide?
If a galaxy is 8.9 Mpc away from Earth and recedes at 497 km/s, what is H. (in km/s/Mpc)? km/s/Mрс What is the Hubble time (in yr)? years How old (in yr) would the universe be, assuming space-time is flat and the expansion of the universe has not been accelerating? years How would acceleration change your answer? If the expansion of the Universe has been accelerating, the Universe could be substantially younger than the value entered above. If the expansion of the Universe has been accelerating, the Universe could be substantially older than the value entered above.
A new astronomical measurement suggests that the Hubble constant is 51 kilometers per second per Megaparsec. If this measurement is correct, what would the Hubble time be in units of years? Is this a plausible value based on other astronomical evidence? Why or why not?
Does Hubble's Law work well for galaxies in the Local Group (such as Andromeda)? No, because dark energy is accelerating the universe's expansion over those distances. No, because we do not know the precise value of Ho. No, because Hubble did not know the Local Group existed when he discovered his law. Yes, it works well for all galaxies. No, because galaxies in the Local Group are bound gravitationally together.
How astronomers determine the distance of a galaxy? Explain.
A galaxy's rotation curve is a measure of the orbital speed of stars as a function of distance from the galaxy's centre. The fact that rotation curves are primarily flat at large galactocen- tric distances (vrot(r) ~ constant) is the most common example of why astronomer's believe dark matter exists. Let's work out why! Assuming that each star in a given galaxy has a circular orbit, we know that the accelera- tion due to gravity felt by each star is due to the mass enclosed within its orbital radius r and equal to v?/r. Here, ve is the circular orbit velocity of the star. (a) Show that the expected relationship between ve and r due to the stellar halo (p(r) xr-3.5) does not produce a flat rotation curve. (b) Show that a p(r) ∞ r¯² density profile successfully produces a flat ro- tation curve and must therefore be the general profile that dark matter follows in our galaxy.
Studying for test: A new astronomical measurement suggests that the Hubble constant is 1112 kilometers per second per Megaparsec. If this measurement is correct, what would the Hubble time be in units of years? Is this a plausible value based on other astronomical evidence? Why or why not?
A galaxy's velocity is measured to be 3112 kilometers per second away from us. What is the distance from us to that galaxy, in units of Megaparsecs (Mpc)? If the value of the Hubble constant is 70 kilometers per second per Mpc.