The document discusses the formation and characteristics of black holes and neutron stars, covering their mass limits, types, and events like gravitational waves. It explains concepts such as the Chandrasekhar limit, event horizons, and the structure of black holes, including both rotating and non-rotating types. Additionally, it touches on the presence of black holes in galaxies, their evolution, and the ongoing research efforts to observe their effects, including Hawking radiation and the merging of black holes.

1. BLACK HOLES &
NEUTRON STARS

2. BLACK HOLES IN
POPULAR CULTURE

7. THE LIFE AND DEATH
OF STARS

9. SMALLER STARS (LIKE OUR SUN)
( Don’t worry, we have around 5
billions years left yet … )

11. CHANDRASEKHAR LIMIT
• Discovered by Subrahmanyan Chandrasekhar
• Awarded Nobel Prize for Physics 1983
• Maximum mass of stable white dwarf
• 1.4 x mass of our Sun
• Above that – Neutron star or Black Hole

12. TOLMAN–OPPENHEIMER–VOLKOFF LIMIT
• Calculated in 1939, derived from similar
equations to the Chandrasekhar limit
• Maximum mass of neutron star
• 2 - 3 x mass of our Sun ( from core remnant )
• Original star mass 15 – 20 solar masses
• Above that – Black Hole

13. ALL ABOUT MASS OF CORE REMNANT
< 1.4 Solar Masses = White dwarf
1.4 - ~3 Solar Masses = Neutron star
> 3 Solar Masses = Black hole

14. MASS OF ORIGINAL STAR
< 10 Solar masses = White dwarf
10 – 29 Solar masses = Neutron star
> 29 Solar masses = Black hole

15. SOME OTHER SCENARIOS….
• Some stars may just vanish to black hole instantly
• Some huge stars blow up entirely, leaving NOTHING
• Some may form Quark Stars

16. NEUTRON STAR
• All empty space of atoms squeezed away
• Density of an atom core
• Tight structure of neutrons
• Matchbox of material = 13m tonnes
• Cube of Earth 135m square

17. BLACK HOLE
• Core completely collapses in on itself
• Mass compacts down to singularity
• Infinite density
• 1 dimension only
• More on this soon…
• Event Horizon – giving black hole its name

18. VERY DENSE MASS…..

19. NON ROTATING BLACK HOLE
• “Schwarzschild Black Hole”
• No spin, no electric charge

20. SINGULARITY
• Infinite density
• 1 dimension – no real “size”
• Space-time curves infinitely
• Physics (esp relativity) breaks down entirely
• Combined quantum & relatively MAY explain one day
• No information can ever escape from singularity

21. EVENT HORIZON
• Shwarzschild radius – light can’t escape
• = Event Horizon
• No information can ever escape
• ( Except Hawking radiation! )
• Past this boundary, space time curves inwards
ONLY

22. GRAVITY – SPACETIME CURVATURE

23. GRAVITY – SPACETIME CURVATURE

24. GRAVITY – SPACETIME CURVATURE

25. GRAVITY – SPACETIME CURVATURE

26. NON ROTATING BLACK HOLE
• “Schwarzschild Black Hole”
• No spin, no electric charge

27. ROTATING BLACK HOLE

28. • Inner / outer horizon
• Static Limit
• ”Location at which space-time is flowing at
the speed of light, making stationary
particles that would be travelling at the
speed of light”
• Ergosphere – region between the two
ROTATING BLACK HOLE

29. ACCRETION DISK & JETS

30. • Strong gravity bends light
• Large scales, gravitational
lensing of distant galaxies
• Similar around black holes
• Interstellar
GRAVITATIONAL LIGHT DISTORTION

31. • Too close to event horizon, yes
• At more distance, same pull as
original star
• Replacing Sun with black hole
NOT VORACIOUS VACUUM CLEANERS!

32. • Micro
• Solar Mass
• Intermediate Mass
• Super Massive
TYPES OF BLACK HOLE

33. • Micro:
TYPES OF BLACK HOLE
• Theoretical, never observed
• May have been created shortly after Big Bang
• May be created in particle accelerators
• Exist for 10th of trillionth of trillionth seconds

34. • Solar Mass:
TYPES OF BLACK HOLE
• Ghost of massive stars
• Size range approx 5 – 64 solar masses
• ~ 100m within our galaxy, mostly invisible
• Observable when in binary pair with star
• Nearest 1600 light years away

35. TYPES OF BLACK HOLE

36. • Intermediate Mass:
TYPES OF BLACK HOLE
• Thought at center of some globular clusters

37. • Supermassive:
TYPES OF BLACK HOLE
• The true monsters!
• Centre of all spiral
& elliptical galaxies
• Largest 30bn –
40bn solar masses!

38. MILKY WAY CENTRE – SAGITTARIUS A*

41. • 2 ly = 51Bn Km
• Nearest star is 37 tr Km
• Fits in 730 times!
MILKY WAY CENTRE – SAGITTARIUS A*

42. • Event horizon estimate 44 M km
• 75% of distance of Mercury to Sun
• Mass 4m Solar masses
• Event Horizon Telescope – imminent!!
MILKY WAY CENTRE – SAGITTARIUS A*

43. • Avg – 0.1% mass of galaxy
• Largest in relation to galaxy 4% – 14%!
SUPERMASSIVE BLACK HOLES

47. • Scientists not yet sure
• Early galaxy gas clouds collapse
• Stellar black hole eats and enlarge
• Clusters of stellar holes combine
• Merging of galaxies combines cores
• Mystery how so big so early!
HOW FORMED?

48. • Ancient and distant
• 12 billion light years away
• Universe 1.8 bn years old
• But ENORMOUSLY bright!
• Dust/Gas rich early galaxies,
accretion disks
• > 200,000 known
• Blasars are where jets point
at us!
QUASARS & BLASARS

49. GRAVITATIONAL WAVES
• Orbiting and merging of
black holes
• Proposed by Einsten 1916
• Detected LIGO 2015
• Two 30 solar mass black
holes merging

50. GRAVITATIONAL WAVES
• eLISA – coming 2030!
maybe…..
• Pathfinder sent 2015
• Detect supermassive BH
mergers in early Universe
• Observe 25k compact
binaries in Milky Way

51. WHAT HAPPENS TO YOU
IF YOU GET CLOSE TO BLACK HOLE?

53. https://vimeo.com/8723702

55. Hawking Radiation
Something CAN escape the
Event Horizon! .. maybe ……
DEATH OF A BLACK HOLE?

57. To come….
NEUTRON STARS?
Future talk 
( There was so much to talk
about black holes! )
Ran out of time…..

58. QUESTIONS?