1. Blueshifted absorption lines: The light from the hot star will be absorbed by the cool interstellar cloud. However, since the cloud is moving towards us, the absorption lines will appear shifted towards shorter wavelengths, resulting in a blueshifted spectrum.
2. Broadening of absorption lines: The motion of the interstellar cloud will introduce Doppler broadening of the absorption lines. This means that the lines will be wider and less defined compared to the spectrum of the hot star alone.
3. Decreased intensity: The cool interstellar cloud will attenuate and scatter some of the light passing through it. As a result, the overall intensity of the spectrum may be reduced.
4. Continuous background: In addition to the absorption lines, there may also be a continuous background component in the resulting spectrum. This could be due to scattering of light by dust or other particles present in the cloud.
5. Possible emission lines: Depending on the physical conditions within the interstellar cloud, there may be emission lines in the resulting spectrum. These lines would be caused by the excitation of atoms or molecules within the cloud.
If light from a hot star passes through a thin cool interstellar cloud that is moving toward you, the resulting spectrum can be characterized by:
1 answer
1 answer