1. Pulsars
Presented by
Rico Bürgler & Shuting Ling

2. What is a pulsar? Stands for pulsating radio star
Is a type of neutron star
Heavily magnetized
Very high rotation speed
Continuous radiation, emits beams across the spectrum
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Pulsars, Rico Bürgler & Shuting Ling

3. Discovery
First observation in 1967 by Jocelyn Bell Burnell and Anthony Hewish in the UK
Pulses in 1.33s intervals
LGM-1 à CP1919 à PSR B
Theories on how the radiation is emitted exist
“We did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission. It is an interesting problem - if one thinks one may have detected life elsewhere in the universe how does one announce the results responsibly? Who does one tell first?”
Lesson descriptions should be brief.
Pulsars, Rico Bürgler & Shuting Ling

4. Illustration Cones = beam, located on the magnetic axis
Golden lines: magnetic field lines
Purple line: rotational axis
Pulsars, Rico Bürgler & Shuting Ling

5. The beam’s origin (rotation-powered pulsars)
Electric field is created
Accelerates protons and electrons on surface
Intense electromagnetic beam results
Loss of energy à slowing down
«death-line» after ~10-100M yrs
Pulsars, Rico Bürgler & Shuting Ling

6. Other categories Accretion-powered pulsars Magnetars
Millisecond pulsars
Pulsars, Rico Bürgler & Shuting Ling

7. Accretion-powered Binary star system Accounts for most X-ray pulsars
Energy source: Gas/Matter from stellar companion.
Stellar wind
Gravitational pull due to distance
Short visible pulsars
Pulsars, Rico Bürgler & Shuting Ling

8. Millisecond Pulsar Rotational period of 1-10ms How are they born?
Recycled/Accretion powered with additional angular momentum
Breaking the chandrasekhar limit
Great clocks
Great for observing nearby matter
Pulsars, Rico Bürgler & Shuting Ling

9. Magnetars Pulsar with high magnetic field Rotation period of 1-12s
Non-periodic flares also generating weaker after flares
Soft Gamma Repeater(SGR)
SGR , found close to Sagittarius A* in Mily Way
B-Field 1'000x of neutron stars 10^8T
Flares: Radiation of energy of about 10k years worth the suns
Pulsars, Rico Bürgler & Shuting Ling

10. Crab pulsar Relatively young neutron star Center of Crab nebula
Pulses in 33ms intervals, roughly 30 times per second
Remnant of SN 1054, observed in 1054
Pulsars, Rico Bürgler & Shuting Ling

11. Applications Probes of the Interstellar Medium
Gravitational Waves Detectors
Clocks
Pulsars, Rico Bürgler & Shuting Ling