Radial velocity/magnitude/luminosity

Thread starter YEAH!
Start date Mar 26, 2011
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Radial

AI Thread Summary

The discussion focuses on estimating the distance between intervening galaxies based on the redshift of absorption lines in a quasar's spectrum. Given a redshift of 0.20 and two sets of absorption lines redshifted by 0.15 and 0.155, participants emphasize the importance of using the Hubble constant (H0 = 70 km/s/Mpc) to calculate distance. The redshift indicates the galaxies are moving away, and the relevant equations involve the relationship between redshift and distance. Participants suggest starting with the formula that connects redshift to velocity and then to distance. This approach provides a method for estimating the spatial separation of the galaxies.

Mar 26, 2011

YEAH!

Homework Statement

The spectrum of a quasar with a redshift of 0.20 contains two sets of absorption lines, redshifted by 0.15 and 0.155, respectively. If h0 = 70 km/s/Mpc, estimate the distance between the intervening galaxies responsible for the two sets of lines.

Homework Equations

H₀= 70 km/s/Mpc

Last edited: Mar 26, 2011

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Mar 27, 2011

zhermes

Cool. So, where might you start? What does the redshift tell you? What equation involves the redshift?

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