SLA_RVGALC

RV Corrn to Galactic Centre

ACTION:
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.
REFERENCE:
Kerr & Lynden-Bell (1986), MNRAS, 221, p1023.