An Introduction to Modern Astrophysics · Problem 24.19

The Early Universe — Carroll & Ostlie

Physics — Astrophysics · rotation-curve-oort-constants

Problem

(a) Estimate

d\Theta/dR

in the solar neighborhood, assuming that the Oort constants

A

and

B

are

+14.8

and

-12.4

km s

^{-1}

kpc, respectively. What does this say about the variation of

\Theta

with

R

in the region near the Sun? (b) If

A

and

B

were

+13

and

-13

km s

^{-1}

kpc, respectively, what would the value of

d\Theta/dR

be? What would this say about the shape of the rotation curve in the solar neighborhood?