galaxies

3 main types of galaxies

Spiral-S(a-d), elliptical-E(0-7), irregular-IRR

spiral galaxies have 2 subtypes

SO-no arms, SB-barred arms

Elliptical galaxies on 0-7 scale

0-sphere, 7-disk

spiral galaxies ranked a-d, what differentiates Sa and Sb

Sa-large bulge, arms tight

Sb-medium sized bulge, arms not so tight

galaxy in which result from a merge in which little gas/dust remains

elliptical-mostly red stars

cause and significance of colors of galaxies

redder-smaller, older stars, less dust

bluer-more dust, newer, bigger arms

what is local group, why does Hubble’s law not apply to it?

Our galaxy cluster, it is gravitationally bound

what objects are believed to be at center of most galaxies

supermassive black holes

what type of galaxy is mix of young and old stars, definitive shape, and active star formation

spiral

what type of galaxy has mostly old stars with very little star formation

elipitcal

what is a void

huge empty region without galaxies

what is a quasar

most powerful active galaxy, most distant +brightest thing we can see

difference between type I and type II population stars

I-high metallicity II-low metallicity

evidence for existence of dark matter

all the extra gravity-too much

how do we know where dark matter is even though it does not interact with light

gravity

what is a Seyfert galaxy

spiral with extra bright core

What is a synchrotron radiation, and what are the galaxies that emit it called?

jets of relative particles from radio galaxies(elliptical)

what will happen when andromeda galaxy collides with milkyway

merge into milk-dramada

give an example of standard candle and explain how it can be used to determine distances

object of known brightness-1a supernova

what is hubble’s law and what insight does it give us about nature of universe

gravitationally bound stuff

what is source for emission of large amounts of x-rays from core and some spiral galaxies

super massive black hole

explain how galaxies can grow and change both in size and structure

collision and merges

what is gravitational lensing

gravity bending light

what can gravitational lensing be used for

measuring mass and seeing further