09 - Relativity, Black Holes, and Quasi-Stellar Objects

Question 1

how does the highly warped space/time called black hole come to be?

Answer 1

the most gigantic stars, whose immense gravity is enough to overcome neutron degeneracy pressure, forces the star to collapse past the neutron star phase

Question 2

an object of zero radius and density/gravity that are infinite

Answer 2

black hole

Question 3

radius of a black hole event horizon, space-time folds back on itself

Answer 3

Schwarzschild radius

Question 4

edge, the boundary of a black hole region, events not visible to an outside observer, the boundary which nothing can escape

Answer 4

event horizon

Question 5

lengthens the wavelength of a photon as it escapes a gravitational field (slows down time)

Answer 5

gravitational redshift

Question 6

slowing of moving clocks or clock in strong gravitational fields

Answer 6

time dilation

Question 7

einstein’s 1916 theory that gravity is due to a curve of space-time, and space and time are related and considered the fabric of the universe. there is no absolute frame of reference for speed/light, even though that’s what we naturally think

Answer 7

general theory of relativity

Question 8

very massive star collapses into a black hole, a possible source of focused gamma-ray burst star more than 15-20M would conserve angular momentum and spin rapidly

Answer 8

hypernova

Question 9

a sudden powerful burst of gamma rays lasting seconds then fading

Answer 9

gamma-ray burst

Question 10

intense radio source at the center of the Milky Way Galaxy, only a few AU in diameter

Answer 10

Sagittarius A (4.6M M)

Question 11

evidence is accumulating that most galaxies contain…

Answer 11

…a supermassive black hole at their centre

Question 12

an attempt to to explain the different types of active galactic nuclei (AGN) using a single model viewed from different directions

Answer 12

unified model

Question 13

a galaxy that is a strong source of radio signals

Answer 13

radio galaxy

Question 14

otherwise typical but with an unusually luminous small core, that fluctuates in brightness

Answer 14

Seyfert Galaxy

Question 15

emit radio energy from two regions (lobes) outflow from the galaxy

Answer 15

Double-Lobed Radio Source

Question 16

small, powerful source of energy in the active core of a very distant galaxy

Answer 16

quasar (quasi-stellar object, QSO)

Question 17

a galaxy whose centre emits large amounts of excess energy, often in the form of radio emissions. They have massive black holes in their centres into which matter is flowing

Answer 17

active galaxy

Question 18

the centres of active galaxies that are emitting large amounts of excess energy

Answer 18

active galactic nuclei (agn)