basics 101

Question 1

Super nova type 1 a

Answer 1

the brightest. It is a white dwarf that gains mass from a binary partner
either by accretion or by a merger. The key is that the mass passes the Chandrasekhar limit and
initiates a thermonuclear explosion. This leads to the formation a remnant that is likely to be a
neutron star.

Question 2

Massive star supernovae (type 2)

Answer 2

— this is a massive star that develops iron core that is so
massive that it is compressed and heated to a point when the iron breaks down into helium and
cools, casing the outer layers to compress inwards. This initiates an enormous burst of fusion.
The spectrum includes hydrogen. The remnant is a neutron star or a black hole.

Question 3

Kilonova

Answer 3

a merger of two neutron stars leads to large explosions that can end in a black hole.
These produce copies heavy elements including gold and platinum.

Question 4

Flux

Answer 4

F = L/(4πD^2) where D is the distance to the object
F = σT^4 (Stefan-Boltzmann Eq)

Question 5

Luminosity of a star

Answer 5

Flux*Surface Area of Sphere(star),
σT^4 * 4πR^2, R is the radius of the star

Question 6

21cm line

Answer 6

neutral hydrogen gas, when spin of the H atom goes from alignment (higher energy) -> spin anti-alignment (lower energy) –> releases a photon in 21cm wavelength

Question 7

lyman transitions

Answer 7

alpha n=2 to n=1
beta n=3 to n=1

Question 8

balmer lines

Answer 8

H-alpha: n=3 to n=2
H-beta: n=4 to n=3

HII regions; ionized gas

Question 9

line of sight velocity

Answer 9

= radial velocity.
it is the stellar velocity component that is in our direction.
The triangle is transverse velocity, radial velocity, and actual velocity of the star

Question 10

Milky Way Mass

Answer 10

10^12 solar mass

Question 11

Milky Way Composition

Answer 11

80% DM
20% Baryonic MAtter
10% gas (90% mainly hydrogen and 10% helium)

Question 12

how to get mass of the milky way

Answer 12

orbits of outer stars, their orbital velocity depends of the total mass inside its orbital radius

Question 13

Brehmstrelung

Answer 13

AKA free-free. particle accelerated by a charged particle nearby, –> release radiation, electrons dominate the amount of F-F radiation

Question 14

tully-fisher relation

Answer 14

1977: for spirals + lenticulars, empirical relationship with mass/magnitude and rotational velocity/emission line width

Question 15

faber-jackson

Answer 15

for non-spirals

Question 16

mass-metallicity relation

Answer 16

increase mass, increase metallicity

Question 17

alpha element vs iron-peak elements

Answer 17

serving as a timing clock. core-collapse vs type 1a SN (check the order)