Chapter 21- Galaxy Birth and Evolution Flashcards

1
Q

why are their different type of galaxies

A

conditions of formation and evolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why does condition of formation of galaxies form different types of galaxies

A

1) Angular Momentum
- more AM= spiral
- less AM= elliptical
2) Density of original protogalaxy
- high density= formed stars fast= elliptical
- less density= formed stars gradually= spiral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why does collision of galaxies form different types of galaxies

A

irregulars form when galaxies collide. they turn into ellipticals later on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

starburst galaxies

A

are forming stars so quickly thatchy would use up all their gas in less than a billion years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

quasars

A
  • very bright radio sources
  • visually look like ordinary stars
  • spectrally look very different to stars
  • EXTREAME REDSHIFTS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what do galaxies around quasars look like

A
  • sometimes appear to be effected by collisions

- radiation of 1000 galaxies packed into a solar system size object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what can explain all properties of quasars

A
  • gas falling into a supermassive blackhole

- assuming that BH accretes at “Eddington rate”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

active galactic nuclei (AGN)

A

-catchall term for all rapidly accreting black holes in galactic centers (aka quasars, seyferts, radio galaxies, blazers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

bigger galaxies have bigger what

A
  • bigger black holes
  • the mass of a galaxies central BH is closely related to the mass of its bulge
  • but not all BH’s are actively accreting gas
  • BH’s need a source of “food” (supply of gas) for it to be active
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the food source for BH’s

A
  • galaxy collisions can fuel AGN

- collisions were more communion early universe because things were closer together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly