You observe a star orbiting in the outer parts of a galaxy. The distance to this galaxy is known, andyou are able to take a spectra of this star and determine its velocity. The star is 19 kpc from thegalaxy center and moving in a circular orbit with speed 382 km/s. Compute the total mass of thegalaxy internal to the star's orbit. You will get a large number; express it in scientific notation and inunits of solar masses [e.g., 4.2e10].[Hint: there is a Box in Chapter 22 of your textbook that will be of help. See also the course formulasheet.]

Given, Distance, R=19kpcR=19×3.08×1019mR=58.52×1019m Speed, v=382×103m/s The velocity of the star is…

Answered: You observe a star orbiting in the…

Similar questions

For a circular velocity profile of the type (r) = ar¹ ar1/9, where a is a constant and r is the radial distance from the centre of a spiral galaxy, find the ratio (r)/(r), where (r) is the epicyclic frequency and 2(r) is the angular velocity. Enter your answer to 2 decimal places.
You find a small satellite galaxy orbiting 66 kpc from the center of a larger galaxy at a speed of 210 km/s. What is the total mass of the galaxy-satellite galaxy system? (Give your answer in terms of MSun.)
In the reading, you were told that there were roughly 10,000 galaxies in the image of the Hubble Ultra Deep Field alone. The image is roughly 10 square arcminutes and there are roughly 1.5*10^8 square arcminutes composing the entire sky. With that in mind and assuming that the Hubble Ultra Deep Field represents an average part of the sky, roughly how many galaxies may exist in the observable universe? (Please include commas for every factor of 1,000; for example 2,343,567,890)
You 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…
Given an image of a disk galaxy, you have measured that the average surface brightness at two radii (R = R1 and R = R2) are I1 and I2 respectively. The disk surface brightness profile has the exponential form of I(R) = I0 e(-R/Rd). What are the values of I0 and Rd for this disk?
Consider an E6 galaxy whose surface brightness is given by the law I(0) = I (0) e-(0/0)1/2, where is the angular distance from the centre of the galaxy along the semimajor axis, I(0) is the central brightness and 0. is the scale angle (i.e. angle at which the surface brightness falls to the value I(0)/e). Calculate the numerical value of its total flux density in units of 1(0)02.
The Tully-Fischer method relies on being able to relate the mass of a galaxy to its rotation velocity. Stars in the outer-most regions of the Milky Way galaxy, located at a distance of 50 kpc from the galactic centre, are observed to orbit at a speed vrot determine the mass in the Milky Way that lies interior to 50 kpc. Express your answer in units of the Solar mass. 250 km s-1. Using Kepler's 3rd Law,
If astronomers find they have made a mistake and our Solar System is actually 7,350 pc rather than 8,300 pc from the center of the Milky Way Galaxy, but the orbital velocity of the Sun is still 225 km/s, what is the minimum mass (in solar masses, MSun) of the Galaxy within the orbit of the Sun?
The Hubble Law, equation (D), can be used to determine the age of the universe. Using your average valueof H, calculate the recessional velocity of a galaxy of a galaxy which is 800 Mpc away.Velocity of a galaxy 800 Mpc away: _______________________________km/sec
An observational survey of distant galaxies is undertaken that involves measuring their distances using cepheid variables and red-shifts using spectroscopy. Explain how cepheid variables can be used to measure the distances to galaxies. A spectral line is observed whose wavelength in the laboratory is de length of this spectral line observed in each galaxy, Xo, is listed in the table, along with the distance, d, to the galaxy. Determine the red-shift and the recession velocity of each galaxy and tabulate your results by making a copy of the table and filling in the blank spaces. Sketch a Hubble diagram using your results and determine the value of the Hubble constant Ho in units of km s-1 Mpc. 650 nm. The wave- Galaxy 1 652.69 Galaxy 2 Galaxy 3 Galaxy 4 Galaxy 5 653.01 do (nm) d (Mpc) 658.54 662.18 681.63 17 19 54 77 200 v (km s-1)
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.
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…

SEE MORE QUESTIONS