How to Calculate Rotation Curves for a Spiral Galaxy?

  • Thread starter Thread starter zaq
  • Start date Start date
  • Tags Tags
    Curve Rotation
AI Thread Summary
To calculate rotation curves for a spiral galaxy, the user seeks guidance on converting a brightness profile (in mag/arcsec²) into surface mass density. They have identified the need for total mass to derive the rotation curve but are unsure how to convert luminosity profile data into mass distribution. The discussion highlights the importance of assuming a mass-to-light ratio for this conversion. The user is looking for references or materials that provide solved exercises on this topic. Assistance with these calculations and methodologies is requested.
zaq
Messages
2
Reaction score
0
I hope this is in the right forum.
I'm trying to see how to calculate rotation curves for a spiral galaxy.
The data I have is brightness profile (mag/arcsec^2) and observed rotation curve - to see how it fits.
from what I found I need the total mass, and for that I need the surface mass density.
I couldn't find how to convert the brightness profile to mass density.
I can probably let MATLAB integrate the spline of the brightness profile, but that's not the mass density, so it wouldn't give me the mass I need.

Would appreciate help.
References to books (preferably with solved exercises) or other material are very welcome.

zaq
 
Astronomy news on Phys.org
no, but thanks for trying.
I think I need to clarify what I'm asking.
The steps I found for calculating an RC are:
get the intensity profile
use that to find the mass distribution
use mass distribution to find g
calculate rotation curve.

I have the luminosity profile. (\mu). The units are mag/pc^2.
I need to convert it to mass distribution \SIGMA r (M/ pc^2).
how do I do that? I know I'm suppose to assume mass to light ratio but how exactly?
 

Thread 'Does it make sense to build new radio telescopes?'

TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better? In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect...
View full post »
Thread 'Could gamma-ray bursts have an intragalactic origin?'

Thread 'Could gamma-ray bursts have an intragalactic origin?'

This is indirectly evidenced by a map of the distribution of gamma-ray bursts in the night sky, made in the form of an elongated globe. And also the weakening of gamma radiation by the disk and the center of the Milky Way, which leads to anisotropy in the possibilities of observing gamma-ray bursts. My line of reasoning is as follows: 1. Gamma radiation should be absorbed to some extent by dust and other components of the interstellar medium. As a result, with an extragalactic origin, fewer...
View full post »

Thread 'Our Beautiful Universe - Photos and Videos'

This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
View full post »

Similar threads

I Rotation curve of a gas disk in an elliptical galaxy
Replies
5
Views
2K
I Measuring the rotation curve of galaxies
Replies
1
Views
2K
I Can Flat Rotation Curves in Spiral Galaxies Be Explained by Dynamical Friction?
Replies
3
Views
2K
B What is the mass distribution and rotation curve of galaxy IC1101?
Replies
4
Views
2K
A Advice needed for exposure time computation for galaxies
Replies
2
Views
2K
I Galaxy Rotation Curves: Newton's Shell Theorem Impact
Replies
19
Views
3K
I Ultraluminous X-ray source in the galaxy NGC 55
Replies
0
Views
1K
I Rotation curves of galaxies as a function of isolation.
Replies
12
Views
2K
I Calculating the Rotation Curves of Galactic Disks
Replies
1
Views
2K
A Galaxy dynamics explained without DM or MOND
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top