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 s1)


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 s1 towards lII = 90, bII = 0.
REFERENCE:
Kerr & Lynden-Bell (1986), MNRAS, 221, p1023.