Hubble image archive

M31 Halo Radial Velocity

This diagram shows the light from a background quasar passing through the vast, gaseous halo around the neighboring Andromeda galaxy (M31), as spectroscopically measured by the Hubble Space Telescope. The colored regions show absorption from two components that make up the halo....

Date
Jan 1, 2020
Mission
Hubble Space Telescope
Archive ID
hubblesite-images-2020-46-4736-image
By

This diagram shows the light from a background quasar passing through the vast, gaseous halo around the neighboring Andromeda galaxy (M31), as spectroscopically measured by the Hubble Space Telescope. The colored regions show absorption from two components that make up the halo. For ionized silicon, a significant absorption is shown in both plots. The more highly ionized carbon is absorbed by only one component. Astronomers can tell the two components apart because their line-of-sight motions, known as radial velocity, cause a Doppler shift that changes the wavelength of light being absorbed.

Credits

NASA, ESA, and E. Wheatley (STScI)

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Source

Image and source material are credited to the official mission archive linked below.

View on NASA.gov

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