Neutron Stars

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Neutron Stars
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Neutron Stars

• Discovery of neutron (1932)
• Neutron Star (1934)
• Landau (unpublished)
• Baade Zwicky With all reserve we advance the
  view that supernovae represent the transitions
  from ordinary stars into neutron stars, which in
  their final stages consist of extremely close
  packed neutrons
• Oppenheimer Volkoff (1938)
• Recognition of the importance of accretion power
  (Salpeter, ) in early sixties

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References

• Padmanabhan (Volume 2)
• Shapiro Teukolsky
• Lattimer Prakash Science (astroph/0405262)
• This is an excellent review
• Kaspi et al. (astroph/0402136)
• Good phenomenological review
• Kaplan 2004 PhD thesis
• For local flavour

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Manifestations of NS
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Manifestations of Neutron Stars

• Low Mass X-ray Binaries (Rocket Flt, Sco X-1)
• Pulsars (IPS Array, CP1919)
• High Mass X-ray Binaries (UHURU, Cen X-3?)
• Binary Pulsars (Arecibo, 191316)
• Soft gamma-ray repeater (Satellites, 5 March
  1979)
• Millisecond Pulsars (Arecibo, 1937214)
• Cluster Pulsars (Jodrell Bank, M28)
• Anomalous X-ray Pulsars (Einstein, 1E2259)
• Thermally emitting NS (ROSAT, RXJ 1856)
• Enigmatic source in Cas A (Chandra)

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A Young Pulsar in G11.2-0.3
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Of Crabs, Shells and Plerions
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Pulsar P-Pdot Diagram
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Nearby X-ray NS

• Cooling NS
• Middle-aged magnetars (decay of B field)
• Accreting from ISM (see Accretion lecture)

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Magnetic Fields

• Cyclotron Frequency omega eB/mc
• Electron cyclotron
• nu 3 Hz B(micro Gauss)
• Energy 10 keV (B/1012) G
• BQED 4x1013 Gauss

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Magnetic Fields

• Cyclotron lines in accreting pulsars (usually
  confirmed by harmonics)
• Features in nearby X-ray bright NS (confused
  state of affairs)
• Some are interpreted as proton cyclotron
• Features are broad in some cases
• See review by Kaspi et al. astroph/0402136

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Masses of Neutron Stars
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Neutron Star Masses
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Radius (Rotation) of NS
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Coherent Oscillations from LMXBs
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Maximum Spin Rate

• 642 Hz Is this the limiting period?
• Neutron stars cannot be spun up (grav radiation
  -gt LIGO)
• Limiting period is fundamental to the equation of
  state of dense matter

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Radius of NS constraints from spin period
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Formation of NS
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Do most SN produce NS?
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Enigmatic Source in Cas A
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What is in the center of SN 1987A?
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Kaplans thesis what is in the centers of shells?
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