Through the use of various measurement techniques, it has been found that most galaxies are rapidly receding (moving away) from the Milky Way, and in fact, galaxies in distant superclusters are moving away from us more rapidly than nearby superclusters.  This recessional motion is present throughout the Universe and is called the

Q: Suppose that the outer stars of a galaxy have an orbital velocity of 150 km/s. If the radius of the…

A: Given data: rgalaxy=4 kpcv=150 km/s Need to determine the orbital period of the outer stars.

Q: An important part of the lifecycle of galaxies like the Milky Way is the self regulation of…

A: Required : The correct choice.

Q: e gravitational energy of a pair of colliding galaxies , each of mass 10 Mo separated by a distance…

A:

Q: (b) Draw the shape of the Milky Way for a spaceship with a velocity of 20%, 50%, and 90% of the…

A:

Q: What would be the Hubble constant if the universe were 18 billion years old?

A: The age of universe is given as, t = 18 billion years (or) t = 18×109 years TO DETERMINE: The…

Q: Consider a universe in which the Hubble constant has been measured to have the value H0 = 50…

A: Hubble's law gives the idea that the universe is continuously expanding, and that galaxies are…

Q: Calculate the critical density of our universe.

A: Our universe is expanding and critical density is defined as the average density of matter that is…

Q: how might you be misled if you studied only the brightest galaxies in a cluster?

A: There are some of the observations which may mislead if you studied only the brightest galaxies in…

Q: Explain how the temperature of hot gas can be used to find out about the gravitational pull of a…

A: Given: The hot gas temperature which is used to find the gravitational pull To find: The explanation…

Q: The matter density in the Universe today is ?m=2.7×10−27kgm−3. What would be the value of the…

A: Given that the matter density in the Universe today is 2.7×10-27 kg/m3 and the Hubble constant is 38…

Q: The redshift of a galaxy is observed to be 0.5. Calculate the recessional velocity of the galaxy.

A: When a light source moves away from the observer the wavelength will shift towards the red region of…

Q: What Hubble constant corresponds to an approximate age of the universe of 1010 y? To get an…

A:

Q: Find the distance to a galaxy whose redshift reveals that it's re- ceding from us at 2.5×104 km/s.

A: As per the Hubble expansion, the universe is expanding. This was observed from the galaxies moving…

Q: All Radio Galaxies have the following number of plasma jets and lobes a) 2  b) 5  c) 1  d) 4…

A: Radio galaxies have two plasma jets and lobes.

Q: Which galaxies are moving the fastest away from us?

A: Our nearest galaxy is Milky way.

Q: Let's say that the number density of galaxies in the universe is, on average, 3 × 10–68 galaxies/m3.…

A: Given :number density of galaxies, n = 3 × 10–68 galaxies/m3            Observable distance by…

Q: If the active core of a galaxy contains a black hole of 106 M, what will the orbital period be for…

A: The expression for the orbital period, T=2πrv    =2πrGMr    =2πr32GM

Q: Spiral Galaxy with 3 differences each and 2 similarities.

A:

Q: Assume that the number density of stars in the Milky Way is 0.14 pc-3. (e) There are 10" stars…

A: Given, Number density of star is, ρ = 0.14 pc-3 Total number of stars in galaxy, N=1011 Let d is the…

Q: Based on Figure 1 below, which galaxies are moving away from us the fastest? Velocity (km/sec) 2000…

A: first option is correct

Q: Observations of quasars have shown us that many are extremely _________, emitting more energy than…

A: Required : Fill in the gaps.

Q: why are the shells visible around some elliptical galaxies significant?

A: The shell structures in the elliptical galaxies indicates the extremely low surface brightness and…

Q: Why aren’t the fluctuations there in the formation of Galaxies and other similar entities?

A: Galaxies and the other similar entities could not be without the existence of fluctuations in the…

Q: How many galaxies are there in the universe?

A: A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and…

Q: How can you explain the fact that the Andromeda Galaxy appears to be approaching us rather than…

A: Each element emits photons only at a certain wavelength. They form either emission or absorption…

Q: how many Galaxy are there in all?

A: The huge collection of gas, dust, and billions of stars and their stars, which are held together by…

Q: Consider a supermassive black hole near the center of a galaxy. Calculate the radius of such an…

A: A supermassive black hole is a black hole that has its mass in the range between 105 to 1010 solar…

Q: If most galaxies are moving away from us, are we at the center of the universe? Why or why not?

A: Introduction: The universe encompasses everything in existence, from the smallest atom to the…

Q: There exists an element visible in the spectrum of galaxies that shows the following spectra when…

A: Introduction: The Doppler effect refers to the apparent shift in the wavelength of a wave when there…

Q: If active core of a galaxy contains a black hole of 10^6 M, what will the orbital period be for…

A:

Q: Briefly discuss and compare the three general types of galaxies.

A: We need to discuss and compare the three general types of galaxies.

Q: If you find a galaxy that is the same size and mass as our Milky Way Galaxy, what orbital velocity…

A: Mass of our galaxy (M1): 4.0 X 1011 M Semi-major axis of the orbit (a): 51 kpc

Q: ___________ are generally expected to be found at the center of most galaxies. If large amounts of…

A:

Q: ring galaxies often have nearby companions. What does that suggest?

A: The origin of ring galaxies is often debated. Some scientists believe that ring galaxies have formed…

Q: How do galaxies form?

A: Two leading theories describe how the first galaxies were created. One says galaxies were born when…

Q: Let's say that the number density of galaxies in the universe is, on average, 3 × 10–68 galaxies/m3.…

A:

Q: What evidence can you cite that the expansion of the universe is accelerating?

A: It is observed that galaxies are moving away from Earth at speeds proportional to their distance.…

Q: If the universe had a density equal to its estimated critical density of 9= 10-30 g/cm3, and if it…

A: Given Critical density ρc =  9×10-30 g/cm3 Mass  (M)                 = 2.0 × 1030 kg

Q: Based on comparison with the Moon, it can be calculated that Andromeda would have to have a diameter…

A:

Q: If astronomers were to find they have made a mistake and our solar system is actually 7.8 (rather…

A: Let m be defined as the mass of the sun, and M be defined as the mass of the galaxy. Since the sun…

Q: What evidence has been found that suggests a black hole at the center of our galaxy?

A: The centre of every galaxy is a matter of great curiosity for astronomers. Blackhole is the object…

Q: You find a small satellite galaxy orbiting 66 kpc from the center of a larger galaxy at a speed of…

A: Given data: Radius of the galaxy r=66 kpc. Velocity of satellite v=210 km/s. According to Kepler's…

Special Relativity

The theory of special relativity discusses how space and time are related to objects traveling along a straight line at a constant speed. Simply stated, as an object reaches the speed of light, its mass becomes infinite and it is unable to move faster than light. This interstellar speed limit has been the topic of much debate in astronomy, and also in science fiction when people consider how to fly over large distances.