Frontiers dark matter

what orbits stars do spiral galaxies have?

ordered

what orbits stars do elliptical galaxies have?

random orbits

How do you find the missing mass in a spiral galaxy?

equate the force due to circular motion and the force due to gravity.

what is the equation for missing mass in a spiral galaxy?

M(r) \= v^2r/a

what is the equation for the doppler shift velocity?

(lambda(obs)-lambda(lab))/lambda(obs)

what is the doppler shift velocity for?

ordered orbits

what is the observed velocity? (hint: i \= inclination angle)

v(obs) \= v(true) *sine (i)

what does a radial distance graph v a radial velocity graph tell you about spiral galaxies? (equation)

M(r) \= kr

what does a radial distance graph v a radial velocity graph tell you about spiral galaxies? (words)

that as the radius increases velocity is constant, there's more mass than it seems. 90% of spiral galaxies are made up of dark matter.

what is doppler broadening (velocity dispersion) used for?

random star orbits

what is the equation for velocity dispersion?

d(Lambda)/lambda \= sigma/c \= v

How do you find the missing mass in random orbit galaxies?

using the virial theorem where v \= sigma

what is the equation for missing mass in random orbit galaxies?

M(tot) \= R*sigma^2/G

what is the total mass equal to in random orbit galaxies?

Mtot \= 10M* therefore dark matter exists

what are the candiates for dark matter?

Baryonic matter (ie planets, black holes, neutron stars) & Exotic matter (i.e neutrinos, axions)

what are the problems with the candiates for dark matter?

Baryonic matter - 5%< & Exotic matter - need to come with alternative theory of gravitation.

what do particle colliders detect for?

missing momentum

what do particle detectors look for?

specific interactions (hard to do)

what do annual modulation techniques look for?

annual patterns due to the earth's motion around the sun.

what is an Active Galactic Nuclei (AGN)?

nucleus of a galaxy and are unusually bright.
light output varies < yr (light flickers)
broad line emissions due to hydrogen.

what do the broad line emissions in AGN mean?

gas moving at random high velocities

what is the equation for the emitting region (1lyr)?

d \= ct

what is the equation for the mass of the emitting region?

Mtot \= dv^2/c

what is the typical mass of emitting region?

10^8M*

what is the most efficient way to create energy?

accretion onto a black hole.

what happens during accretion?

KE \---\> Luminosity

what is the change in mass equation where all material dropped onto a black hole is converted to luminosity?

dm/dt \= 2L* (shecter fn)/c^2

for seyfert (sy) AGNs what are the emission lines for sy1?

broad and narrow

for seyfert (sy) AGNs what are the emission lines for sy2?

narrow

for seyfert (sy) AGNs what is the optical lumiosity for sy1?

bright

for seyfert (sy) AGNs what is the optical lumiosity for sy2?

faint

for seyfert (sy) AGNs what is the x-ray/IR lumionsity for sy1 & sy2?

the same