Consider a source of radiation with a luminosity of 8x104 lo located at a distance of 2 kpc. (a) assume that the light has a wavelength of λ 550 nm. how many photons per second does the keck telescope receive from this source (the diameter of keck is 10 m)? (b) if this source were to emit in the x-rays, with photons that have an energy~1 kev, how many photons per second would the chandra x-ray ( )beorea ory texx: lve the aroa of chandra about 0.h