What do we mean when we say that a particle is weakly interacting?
What do we mean when we say that a particle is a weakly interacting particle? It interacts only through the weak force and the force of gravity. Since they do not interact with the electromagnetic force, they do not feel friction or drag and hence do not contract with the rest of the protogalactic cloud.
What do we mean when we say that the rotation curve for the Milky Way galaxy is flat?
What do we mean when we say that the rotation curve for a spiral galaxy is “flat“? Gas clouds orbiting far from the galactic center have approximately the same orbital speed as gas clouds located further inward. It bends or distorts the light coming from galaxies located behind it.
What are WIMPs and MACHOs and why are they important?
WIMPs and MACHOs are two of the most popular DARK MATTER candidates. It is important to identify the dark matter, but since it is easy to invent substances that could fill intergalactic space and yet have escaped detection, there are a very large number of dark matter candidates.
What does WIMP mean dark matter?
Weakly interacting massive particle (WIMP), heavy, electromagnetically neutral subatomic particle that is hypothesized to make up most dark matter and therefore some 22 percent of the universe.
What is the evidence of dark matter in our galaxy?
Primary evidence for dark matter comes from calculations showing that many galaxies would fly apart, or that they would not have formed or would not move as they do, if they did not contain a large amount of unseen matter.
What is the evidence that our galaxy contains a large amount of dark matter?
What evidence is there of Dark Matter? a. Orbital speeds in the Milky Way remain high even very far from the center, indicating that a large amount of dark matter leis beyond our galaxy’s visible regions.
How do we know dark matter exists?
Scientists study dark matter by looking at the effects it has on visible objects. Scientists believe that dark matter may account for the unexplained motions of stars within galaxies. Computers play an important role in the search for dark matter information.
Why does the rotation curve of the Milky Way imply the presence of dark matter?
Because The Galactic Halo Has Retrograde And Prograde Orbits Because The Milky Way Would Not Rotate Without Any Dark Matter Because We Directly Detected Dark Matter At The Outskirts Of The Milky Way Using More Sensitive Telescopes And Instruments Because Stars And ISM Clouds
Do all galaxies rotate?
Astronomers have discovered that all galaxies rotate once every billion years, no matter how big they are. “But regardless of whether a galaxy is very big or very small, if you could sit on the extreme edge of its disk as it spins, it would take you about a billion years to go all the way round.”
Is dark matter a WIMPs?
For decades, physicists have hypothesized that weakly interacting massive particles (WIMPs) are the strongest candidate for dark matter — the mysterious substance that makes up 85% of the Universe’s mass.
What is dark matter made of?
But the most common view is that dark matter is not baryonic at all, but that it is made up of other, more exotic particles like axions or WIMPS (Weakly Interacting Massive Particles).
Is a neutrino a wimp?
Also, in contrast to MACHOs, there are no known stable particles within the Standard Model of particle physics that have all the properties of WIMPs. The particles that have little interaction with normal matter, such as neutrinos, are all very light, and hence would be fast moving, or “hot”.
Is Wimp a bad word?
Forget “dork,” “nerd” and “bozo.” The word “wimp,” elevated from the ranks of insult nouns to serious slang, is a four-letter word so mighty that it can undermine political campaigns, cause heated debates between men and women and run in inch-high headline type from coast to coast.
Is Higgs boson dark matter?
Dark matter, which makes up around 85% of the mass of the universe, has only been observed indirectly, through gravitational effects. No particles of this substance have been observed in a laboratory.
Are axions dark matter?
“The axion actually makes a really good dark matter candidate,” says Peter Graham of Stanford. Beyond the expectation that the cosmos should be awash with the particles, axions would be naturally “dark,” meaning they would hardly interact with ordinary matter at all.