Problem B.4: Distribution of Dark Matter he most mass of our Milky Way is contained in an inner region close to the core with radius Ro. because the mass outside this inner region is almost constant, the density distribution can be written as following (assume a flat Milky Way with height zo): Po, rS Ro p(r) = %3D 0, r> Ro (a) Derive an expression for the mass M(r) enclosed within the radius r. (b) Derive the expected rotational velocity of the Milky Way v(r) at a radius r. (c) Astronomical observations indicate that the rotational velocity follows a different behaviour: 5/2 1+e-4r/Ro Vobs (r) = VGT pozo Ro %3D Draw the expected and observed rotational velocity into the plot below: 2.0 1.5 r-Ro 1.0 0.5 0.0 0. 1 2 3. 4. 6. 8. 10 Radius from Center r (Ro] (d) Scientists believe the reasons for the difference to be dark matter: Determine the rotational velocity due to dark matter v pDM (r) from Ro and draw it into the plot above. (e) Derive the dark matter mass MpM (r) enclosed in r and explain its distributed. (f) Explain briefly three theories that provide explanations for dark matter. Rotational Velocity [yGapozo Ro]

icon
Related questions
Question

Please answer this....Make the answer more explanatory

Problem B.4: Distribution of Dark Matter
he most mass of our Milky Way is contained in an inner region close to the core with radius Ro.
because the mass outside this inner region is almost constant, the density distribution can be
written as following (assume a flat Milky Way with height zo):
Po, rS Ro
p(r) =
%3D
0,
r> Ro
(a) Derive an expression for the mass M(r) enclosed within the radius r.
(b) Derive the expected rotational velocity of the Milky Way v(r) at a radius r.
(c) Astronomical observations indicate that the rotational velocity follows a different behaviour:
5/2
1+e-4r/Ro
Vobs (r) = VGT pozo Ro
%3D
Draw the expected and observed rotational velocity into the plot below:
2.0
1.5
r-Ro
1.0
0.5
0.0
0.
1
2
3.
4.
6.
8.
10
Radius from Center r (Ro]
(d) Scientists believe the reasons for the difference to be dark matter: Determine the rotational
velocity due to dark matter v pDM (r) from Ro and draw it into the plot above.
(e) Derive the dark matter mass MpM (r) enclosed in r and explain its distributed.
(f) Explain briefly three theories that provide explanations for dark matter.
Rotational Velocity [yGapozo Ro]
Transcribed Image Text:Problem B.4: Distribution of Dark Matter he most mass of our Milky Way is contained in an inner region close to the core with radius Ro. because the mass outside this inner region is almost constant, the density distribution can be written as following (assume a flat Milky Way with height zo): Po, rS Ro p(r) = %3D 0, r> Ro (a) Derive an expression for the mass M(r) enclosed within the radius r. (b) Derive the expected rotational velocity of the Milky Way v(r) at a radius r. (c) Astronomical observations indicate that the rotational velocity follows a different behaviour: 5/2 1+e-4r/Ro Vobs (r) = VGT pozo Ro %3D Draw the expected and observed rotational velocity into the plot below: 2.0 1.5 r-Ro 1.0 0.5 0.0 0. 1 2 3. 4. 6. 8. 10 Radius from Center r (Ro] (d) Scientists believe the reasons for the difference to be dark matter: Determine the rotational velocity due to dark matter v pDM (r) from Ro and draw it into the plot above. (e) Derive the dark matter mass MpM (r) enclosed in r and explain its distributed. (f) Explain briefly three theories that provide explanations for dark matter. Rotational Velocity [yGapozo Ro]
Expert Solution
Step 1

 Since your question has multiple sub-parts, we will solve the first three sub-parts for you. If you want the remaining sub-parts to be solved, then please resubmit the whole question and specify those sub-parts you want us to solve.

To answer:

(a) Derive an expression for the mass M(r) enclosed within the radius r.

(b) Derive the expected rotational velocity of the Milky way v(r)  at a radius r.

(c) Draw the expected rotational velocity into the plot given.

steps

Step by step

Solved in 2 steps

Blurred answer