Final

Question 1

How do we know if a black hole is present?

Answer 1

X-rays (particles speeding up)
Stars circling black hole
Gravitational lensing

Question 2

Black hole mass range

Answer 2

Stellar: 3.2-100 solar mass
Supermassive: millions-billions? solar mass

Question 3

White dwarf mass range

Answer 3

1.4 solar masses - chandrasekhar limit

Question 4

Neutron star mass range

Answer 4

1.4-3.2 solar masses

Question 5

What is a neutrino detector?

Answer 5

Scintillator -

Question 6

SN 1987A

Answer 6

Supernova

Question 7

Gamma ray bursts

Answer 7

Brightest EM event in the universe

Narrow beam of intense radiation as high-mass star collapses

Question 8

White dwarf

Answer 8

Chandrasekhar limit, nova

Question 9

Neutron star

Answer 9

Small, dense

Chandrasekhar limit, nova

Question 10

Supernovae

Answer 10

sn

Question 11

Neutrinos

Answer 11

n

Question 12

Diagram of milky way

Answer 12

d

Question 13

Diameter and thickness of milky way

Answer 13

Diameter - 100,000-120,000 ly

Thickness - 1,000 ly

Question 14

Globular cluster

Answer 14

Spherical collection of stars that orbits a galactic core
High stellar density toward center
More stars, older than open clusters
~150 discovered in MW
Largest/most massive clusters

Question 15

The Sun

Answer 15

sun

Question 16

SGR A

Answer 16

Bright radio source at center of MW
Supermassive black hole
2.6M solar masses

Question 17

Wavelength range of light that can penetrate dust

Answer 17

Infrared

700nm-1mm

Question 18

Types of galaxies

Answer 18

Elliptical - largest, formed from collision, core of clusters - older stars
Spiral - bulge, disk, halo - middle aged stars
irregular - no structure - younger

Question 19

Andromeda

Answer 19

Spiral galaxy, closest to MW

2.5Mly

Question 20

Standard candle

Answer 20

Object with a known luminosity
Parallax
Cepheid variable - period corresponds to magnitude
Planetary nebula
Type 1a supernova
Gravitationally lensed quasar

Question 21

Hubble

Answer 21

h

Question 22

Hubble’s Law

Answer 22

V=HoD
V is the observed velocity of the galaxy away from us, usually in km/sec
H is Hubble’s “constant”, in km/sec/Mpc
D is the distance to the galaxy in Mpc

Question 23

Hubble constant

Answer 23

Estimated by measuring the redshift of distant galaxies and then determining the distances to the same galaxies (by some other method than Hubble’s law)
Initially 50-90 (km/s)/Mpc
Now 70 (km/s)/Mpc

Question 24

Cosmological principle

Answer 24

‘Viewed on a sufficiently large scale, the properties of the Universe are the same for all observers.’

Question 25

Star formation

Answer 25

sf

Question 26

Age of universe, Ho

Answer 26

22 (km/s)/Mly | 13.8By

Question 27

Evolution of galaxies

Answer 27

j

Question 28

Galaxy interaction

Answer 28

gi

Question 29

Protogalactic cloud

Answer 29

pgc

Question 30

Galaxy collision

Answer 30

gc

Question 31

Starburst galaxy

Answer 31

Galaxy forming stars faster than normal Will consume gas reservoir quickly Large amount of cool molecular gas in small volume

Question 32

Quasar

Answer 32

Furthest visible objects Quasi-stellar radio source Supermassive black hole surrounded by accretion disk Radio, x-ray, light

Question 33

Radio galaxy

Answer 33

rg

Question 34

Supermassive black holo - location, evidence

Answer 34

smbh

Question 35

Active galactic nuclei

Answer 35

agn

Question 36

Dark matter - evidence

Answer 36

dm

Question 37

MACHOS

Answer 37

Massive Astrophysical Compact Halo Object Black hole, neutron star, brown dwarf, unassociated planet, white dwarf?, faint red dwarf? Detected when passing in front of a star and gravitational lensing

Question 38

WIMPS

Answer 38

Weakly Interacting Massive Particles Weak force and gravity - no EM so can't be seen directly, no strong force so do not interact with nuclei Detection - get trapped in Sun, annihilate each other and form neutrinos

Question 39

Scale of local group

Answer 39

>54 galaxies, counting dwarf galaxies Part of Virgo Supercluster Milky Way/Andromeda are most massive

Question 40

Galaxy clusters - types, distribution

Answer 40

k

Question 41

Gravitational lensing

Answer 41

Light from a distant source bends around a massive object

Question 42

Dark energy

Answer 42

Hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe

Question 43

Percentages (DM, DE, matter)

Answer 43

75% dark energy 20% dark matter 5% ordinary matter

Question 44

Scenarios for the fate of the universe

Answer 44

Closed universe - recollapsing - big crunch - no DE Open universe - accelerating - big freeze Critical universe - expansion asymptotically approaches zero - big freeze Coasting universe - no accelerating - big freeze

Question 45

Cosmic microwave background - observed T, initial T, time of occurrence

Answer 45

Thermal radiation filling the observable universe almost uniformly Observed T - 2.725 K Initial T - >10^32 K Time of occurence - 378,000 years, recombination

Question 46

Inflation of the universe

Answer 46

GUT force split into strong and electroweak forces | Universe inflated 10^50x

Question 47

Big bang - evidence

Answer 47

Hubble's Law, expansion of space (redshifts) CMB Abundance of primordial elements (helium-4, helium-3, deuterium, lithium-7) Galactic evolution - first quasars and galaxies formed 1By ago Primordial gas clouds - no elements heavier than hydrogen and deuterium

Question 48

Abiogenesis

Answer 48

Process of life evolving from organic compounds 1. organic precursor molecules appear 2. RNA molecules self-replicate 3. membrane-enclosed pre-cells 4. true cells with RNA genome 5. modern cells with DNA genome

Question 49

Habitable ZOne

Answer 49

Region where planetary-mass objects with sufficient atmos. pressure could support liquid water at surface

Question 50

Drake Equation

Answer 50

Likelihood of discovering a communicative civilization | N = number

Question 51

GUT force

Answer 51

Grand Unified Theory | Combination EM, strong, weak