(wave frequency difference due to relative velocity difference with source)
A Doppler shift (or Doppler effect), in astronomy, is typically
a change in electromagnetic radiation frequency and wavelength due to
a radial velocity between the observer and the observed.
It is a general property of waves, and is popularly known as
the reason the sound of a passing vehicle has a higher tone as the
vehicle approaches and lower when it has passed.
For EMR, the relationship between wavelength and relative velocity is:
δf = ——
- δf - change in frequency.
- δv - relative velocity.
- c - speed of the waves, e.g., speed of light.
Doppler shifts can also be caused by gravity, due to general relativity,
offering another method of observation and analysis.
dark matter halo
velocity dispersion (σ)
double-line spectroscopic binary
frame of reference
Galactic All-sky Survey (GASS)
line shape function
position-position-velocity space (PPV)
radial velocity (RV)
stellar mass determination
stellar radius determination
Tully-Fisher relation (TFR)