Your research team analysis the light of a mysterious object in space. By using a spectrometer, you can observe the following spectrum of the object. The Hα line peak is clearly visible: (a) Mark the first four spectral lines of hydrogen (Hα, Hβ, Hγ, Hδ) in the spectrum. (b) Determine the radial velocity and the direction of the object’s movement. (c) Calculate the distance to the observed object. (d) What possible type of object is your team observing?
Answers
Your research team analysis the light of a mysterious object in space. By using a spectrometer, you can observe the following spectrum of the object. The Hα line peak is clearly visible: (a) Mark the first four spectral lines of hydrogen (Hα, Hβ, Hγ, Hδ) in the spectrum. (b) Determine the radial velocity and the direction of the object’s movement. (c) Calculate the distance to the observed object. (d) What possible type of object is your team observing?
Explanation:
The radial velocity and the direction of the object’s movement will be given by:
v=zc=(3⋅10 ⁵ )(800 / 656.28 −1)
=65700 km/s.
The velocity is positive. The wavelengths elongate. ∴, the object moves away from the observers.
(c)Using Hubble's law, the distance will be:
D= v/ H₀ = 65700 km/s /72 km/s/MPc
=913 MPc.
(d) The object is a galaxy.