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:

$$[\,\alpha,\delta\,]$$ R2000,D2000

RETURNED:

sla_RVGALC 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 $l^{I\!I}=90^{\circ}$, $b^{I\!I}=0$.

REFERENCE:

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