Velocity component in a given direction due to the rotation of the Galaxy.
CALL:
R = sla_RVGALC (R2000, D2000)
GIVEN:
R2000,D2000
R
J2000.0 mean [α,δ] (radians)
RETURNED:
sla_RVGALC
R
Component of dynamical LSR
motion in direction R2000,D2000
(km s−1)
NOTES:
(1)
Sign convention: the result is positive when the LSR is receding from the given point
on the sky.
(2)
The Local Standard of Rest used here is a point in the vicinity of the Sun which is in
a circular orbit around the Galactic centre. Sometimes called the dynamical LSR, it is
not to be confused with a kinematical LSR, which is the mean standard of rest of star
catalogues or stellar populations.
(3)
The dynamical LSR velocity due to Galactic rotation is assumed to be 220 km s−1
towards lII=90∘,
bII=0.