delta_f¶

Radio_Astronomy.delta_f(delta_v, frequency)¶

Frequency shift corresponding to a velocity shift.

For example, 1 km/s = 74 kHz at 22 GHz water line and 6 kHz at the OH line::

In [1]: from Radio_Astronomy import *

In [2]: delta_f(1e3,22.235e9)/1e3 Out[2]: 74.167976567309097

In [3]: delta_f(1e3,1776e6)/1e3 Out[3]: 5.9240983307191799

:param delta_v : velocity in m/s

:param frequency : rest frequency in Hz