What consequence results from observing light emitted by material on the far side of a rotating galaxy moving away from us?
Answer
A redshift
Material moving away from the observer causes the light waves to stretch, which corresponds to a redshift—a shift toward longer wavelengths.
#Videos
Astrophysics: Galaxy Rotation Curves and Dark Matter - YouTube
Related Questions
What primary measurement technique allows astrophysicists to calculate a galaxy's spin rate?When observing the near side of a spiral galaxy moving towards the observer, how are the spectral lines shifted?What consequence results from observing light emitted by material on the far side of a rotating galaxy moving away from us?What specific spectral line is famously measured in rest frame to determine radial velocity?What is the resulting graph called when measured orbital velocities are spatially mapped against distance from the galactic center?If a galaxy's inclination ($i$) is known, how is the observed radial velocity ($v_{obs}$) converted to the true circular velocity ($v_{circ}$)?According to Newtonian mechanics for a spherical mass distribution, what equation relates the orbital velocity ($v$) to the enclosed mass ($M(r)$) at radius ($r$)?How does the idealized Keplerian prediction suggest orbital velocity should change as radius increases past where visible mass ends?What is the key observational contradiction between inferred gravitational mass and observed visible mass in spiral galaxies?For systems like elliptical galaxies, what measurement is used instead of rotation curves to estimate total mass?What theorem is used to estimate the total mass in elliptical galaxies by relating kinetic energy derived from dispersion to potential energy?