Spiral Galaxy with 3 differences each and 2 similarities.

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.

If a galaxy has an apparent radial velocity of 2000 km/s and the Hubble constant is 70 km/s/Mpc, how far away is the galaxy?

What evidence can you cite that our galaxy has a galactic corona?

Why can't the evolution of galaxies go from elliptical to spiral? From spiral to elliptical?

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…

The Sun is at a distance of about 8 kpc from the galactic center and moves around the galactic center in a circular path with a velocity of about 220 km s. Make a rough estimate of the mass of the Galaxy.

The hydrogen Balmer line has a wavelength of 486.1 nm. It is shifted to 565 nm in a galaxy's spectrum. What is the radial velocity (in km/s) of the galaxy? (Indicate the direction with the sign of your answer.)