The Hydrogen Balmer line Hg has a wavelength of 486.1 nm. This wavelength is shifted to 563.9 nm in the spectrum of quasar 3C 273. Calculate how far is the quasar receding from us? (Hint: Use Doppler formula: Vr ; c = 3.00 × 105 km/s). λο = -

If a standard passenger aircraft can fly at 0.26 km/s (582 mph), how long (in yr) would it take to reach the Sun? yr How long (in yr) would it take to reach the galactic center? (Note: 1 pc = 3.1 ✕ 1013 km. The radius of the Sun's orbit around the galactic center is approximately 8,300 pc.) yr

Certain spiral galaxy is 9.9 Mpc away from us. How fast in km/s is this galaxy moving away from us?    Note: Assume a value of the Hubble constant of 71.1 km/s/Mpc

Suppose you have obtained spectra of several galaxies and have measuerd the observed wavelength of the H-Alpha line (rest wavelength = 656.3 nm) to be Galaxy 1: 658.1 nm. Galaxy 2: 667.1 nm. Galaxy 3: 677.6 nm. Assuming a Hubble Constant of 72.5 km/s/Mpc, calculate the distance to each of these galaxies (answer in Mpc)

If a quasar is 1,640 times more luminous than an entire galaxy, what is the absolute magnitude of such a quasar? (Note: The absolute magnitude of the Milky Wag Galaxy is about -21. Use the formula for magnitude and flux ratio, Mv - Ma = 2.5log(Fa\Fb)).

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…

If Hubble’s constant is taken to be 70 ??? ???, and a quasar is found to have a radial velocity equal to 95% of the speed of light, how far is the quasar in Mpc? (Hint: Use Hubble’s Law and solve for the distance; and the speed of light in vacuum is: ?=3.0×105 ??/?).

If a quasar is 2,000 times more luminous than an entire galaxy, what is the absolute magnitude of such a quasar?  Note: The absolute magnitude of the Milky Way Galaxy is about −21. Hint: Use the formula for magnitudes and flux ratios,