Week 10 Compact Objects

Question 1

define a compact object

Answer 1

stellar objects formed at the end of the life of a star

Question 2

what are the three types of compact object in ascending mass order

Answer 2

white dwarf
neutron star
black hole

Question 3

what models the pulsation of neutron stars

Answer 3

lighthouse model

Question 4

define interpulses

Answer 4

multiple pulses separated due to the inclination angle of the pulses

Question 5

when does spin down occur

Answer 5

energy is lost from the system largely due to magnetic dipole radiation

Question 6

why is spin down useful

Answer 6

the spin down rate allows you to define the KE loss rate and hence the magnetic field strength of the neutron

Question 7

what is a spin-up glitch

Answer 7

when the difference in spin between the crust and interior builds up the superfluids couples to the crust and angular momentum gets transferred leading to spin up for brief moment

Question 8

what are the 4 types of neutron star

Answer 8

magnetars
young newly formed pulsars
normal bulk of population
milli second pulsars

Question 9

describe the four types of neutron star

magnetars, young newly formed pulsars, normal bulk of population, milli second pulsars

Answer 9

> Magnetars - slow rotating with large spin down rate due to very strong mag field
Young - Large change in E field, fast spinning with low characteristic age
Bulk - Standard Neutron
MSP - very fast spin with mass transfer from companion star