(a) The redshift of the quasar LPIF13 is z = 2.58 and we know that

    delta(lambda)
z = ------------- .  For (lambda) = 656.3 nm, the hydrogen-alpha line,
      (lambda)

the line appears at (lambda) + delta(lambda) = 656.3 + (2.58 * 656.3)
= 2350 nm.  For (lambda) = 486.1 nm, the hydrogen-beta line, the line
appears at 486.1 + (2.58 * 486.1) = 1740 nm.

(b) For the velocity at which LPIF13 is moving away from Earth, we must use
the relativistic Doppler formula (the non-relativistic Doppler formula
would give an apparent velocity greater that the speed of light and 
is thus wrong).

           1 + v/c
  z = sqrt(-------) - 1.   Since z = 2.58, we can move the 1 over to get
           1 - v/c

                 1 + v/c
  (2.58 + 1)^2 = -------  which leads to  (12.8) * (1 - v/c) = 1 + v/c
                 1 - v/c

  and thus 12.8 - 12.8(v/c) = 1 + (v/c), or 11.8 = 13.8(v/c).  So 

  v = c * (11.8)/(13.8) = 2.57 * 10^8 m/sec.  So the expansion of the

  universe is carrying LPIF13 away at about 86% the speed of light.

c) When high-density, low-energy clouds of gas are illuminated, they
produce absorption lines at the rest wavelengths of the atoms in the 
clouds.  Since this cloud contains hydrogen gas, we know that absorption
lines would be produced at rest wavelengths of 656.3 nm (H-alpha) and
486.1 nm (H-beta).  Since these clouds are not at rest, but rather at
redshift z = 1.5, these absorption lines would be seen at wavelengths

  656.3 * (1 + 1.5) = 1641 nm for H-alpha, and
  486.1 * (1 + 1.5) = 1215 nm for H-beta.