dark matter galactic rotation
Skip this Video
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 19


  • Uploaded on

2012. ASTRO SUMMER SCHOOL. DARK MATTER & GALACTIC ROTATION. In 1933, Fritz Zwicky calculated the mass of the Coma Cluster. More evidence was discovered by Vera Rubin who measured the rotation curves of many galaxies during the 1970s. The expected distribution of dark matter in the Milky Way.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'DARK MATTER & GALACTIC ROTATION' - faraji

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
More evidence was discovered by Vera Rubin who measured the rotation curves of many galaxies during the 1970s.
CMBR Power Spectrum

The first peak gives us information about the curvature of the Universe.

The ratio of the odd peaks to the even peaks gives us the baryon density.

The third peak tells us about the density of dark matter.

We can alter the cosmological parameters so that the curve fits the observed data.

This slide will not work

correctly without a plugin. Go to:


to view the embedded webpage directly.

More evidence for dark matter

Velocity dispersion of galaxies

Measurements of the velocities of galaxies within clusters.

Acoustic oscillations

Periodic fluctuations in baryonic matter caused by acoustic waves in the early Universe.

Type Ia supernovae measurements

Put a limit on the amount of dark energy hence constrain dark matter

Structure formation

If the Big Bang model is correct, dark matter is required to allow structures to form.

Rotation curves

A solid body (i.e. a disk) will have a rotational velocity that is proportional to distance – as R increases, v increases.

Since , for objects that are gravitationally bound (i.e. not a solid disk), we expect v to be proportional to

Galaxies do not follow Keplerian rotation, outside of the core of the galaxy, v is approximately constant. This provides evidence for dark matter.

Cryogenic detector experiments

Cryogenic detectors, operating at temperatures below 100mK, detect the heat produced when a particle hits an atom in a crystal absorber such as germanium.

CRESST, Gran Sasso, Italy

CDMSII, Soudan Mine, Minnesota

Noble liquid experiments

Noble liquid detectors detect the flash of scintillation light produced by a particle collision in liquid xenon or argon.

DEAP, Ontario, Canada

XENON, Gran Sasso, Italy

Indirect detection methods

Indirect detection experiments search for the products of WIMP annihilation. If WIMPs are Majorana particles (the particle and antiparticle are the same) then two WIMPs colliding could annihilate to produce gamma rays or particle-antiparticle pairs. This could produce a significant number of gamma rays, antiprotons or positrons in the galactic halo. The detection of such a signal is not conclusive evidence for dark matter, as the production of gamma rays from other sources are not fully understood.

EGRET - Energetic Gamma Ray Experiment Telescope

PAMELA - Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics

GLAST - Gamma-ray Large Area Space Telescope (also known as Fermi)