Diversity across the P P Diagram

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Diversity across the P P Diagram
R. N. Manchester
Australia Telescope National Facility, CSIRO
Sydney Australia
Summary
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• The P P diagram extended
• Accretion-powered pulsars
• Globular-cluster pulsars
• Magnetars, high-energy pulsars and SNR
  associations
• Binary pulsars
• Ordinary pulsars

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The P P Diagram
Galactic Disk pulsars
P Pulsar period P dP/dt slow-down rate
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• For most pulsars P 10-15
• MSPs have P smaller by about 5 orders of
  magnitude
• Most MSPs are binary, but few normal pulsars are
• P/(2P) is an indicator of pulsar age
• Surface dipole magnetic field (PP)1/2

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Great diversity in the pulsar population!
Data from ATNF Pulsar Catalogue, V1.36
www.atnf.csiro.au/research/pulsar/psrcat
(Manchester et al. 2005)
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The Extended P P Diagram
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Includes

• Globular cluster pulsars
• Accretion-powered pulsars LMXBs and HMXBs
• Non-degenerate stellar pulsars (Brown dwarfs,
  Magnetic A stars)

Many GC pulsars and accretion-powered pulsars
have P lt 0 (square symbol)
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Pulse Period Histogram

• Currently1886 known (published) pulsars
• 1674 rotation-powered disk pulsars
• 192 MSPs
• 108 in globular clusters
• 56 accretion-powered pulsars
• 13 AXP/SGR
• 7 XDINs
• 4 non-degenerate pulsars
• 20 extra-galactic pulsars

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The Non-Degenerate Stellar Pulsar CU Vir

• Magnetic chemically-peculiar A star
• Rotation period 44988.746 seconds
• Two sharp radio pulses per period
• Broad-band 100 circular emission
• Probably electron cyclotron maser emission
  coherent emission in direction perpendicular to
  electron motion, i.e., along field line (Melrose
  Dulk 1982)
• Magnetic-pole model radius-to-frequency
  mapping(!)
• Step increases in period, a few seconds every
  10-15 years P 10-13

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• Three other NDG pulsars known
• All brown dwarfs
• Periods in range 2.1 3.5 hours

(Trigilio et al. 2008)
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Accretion-Powered Pulsars

• Two main groups LMXBs and HMXBs
• Distinct group of MSPs all LMXBs
• Two classes of MSP persistent and burst
  (but note that persistent class often seen only
  in bursts!)
• X-ray emission in persistent type from
  accretion column (AMSP)
• X-ray emission in burst type from nuclear
  burning on NS surface (Type I burst) (NMSP)

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High-mass X-ray Binary Pulsars

• Neutron star with O- or B-star companion,
  typically 10 30 solar masses often Be star
• Companion generally identified optically
• 30 with known pulsation period
• Periods range from few seconds to few hundred
  seconds
• Orbital periods range from few days to few
  hundred days
• Wind-fed accretion spin-up and spin-down
• Cen X-3 is an example
• Comp. V779 Cen, O6 star
• Highly modulated X-ray emission power-law
  spectrum with absorption
• P 4.82 s, Pb 2.08 d

Cen X-3
(Suchy et al. 2008)
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Low Mass X-ray Binaries Long-Period Systems

• Neutron star with companion of low mass,
  generally lt 1 Msun
• Pulse periods in range 1 s to 100 s
• Orbital periods in the range 0.02 300 days
• X-ray spectrum power-law plus blackbody
• 4U 1626-67 is an example
• An ultra-compact system Pb 42 min
• Pulse period 7.7 s
• Episodes of spin-up and spin-down with similar
  P
• Companion mass 0.04 Msun
• Optically identified (17 mag) optical emission
  strongly modulated at pulse period

4U 1626-67 7.7 sec
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(Krause et al. 2007)
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Accretion-Powered (Persistent) MSPs

• Highly coherent pulsations
• Ten systems known
• Pulse frequencies in range 180 600 Hz
• Orbital periods in range 0.02 0.4 days (two
  systems dont yet have identified orbits)
• Four systems are ultra-compact these have
  truly persistent emission
• In the remaining systems, pulsations are only
  seen in transient outbursts lasting weeks
• Both spin-up and spin-down observed
• Accretion rates very low channelled by polar
  field lines modulation at NS spin period

Progenitors of radio MSPs!
(Wijnands 2005 Watts 2005 Galloway et al. 2005)
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Nuclear-powered (Type I) Burst MSPs
4U 1728-34

• Pulsations seen in short (few second) Type I
  bursts due to nuclear burning on the
  neutron-star surface
• Pulse frequency increases in initial phase of
  burst but stabilises toward the end

(Strohmayer et al 1996)

• 12 or 13 systems known (XTE J1739-285 with
  modulation at 1122 Hz is controversial)
• Pulse frequencies in the range 44 619 (or
  maybe 1122) Hz
• Type I bursts have been observed from five of
  the accretion-powered MSPs (not the ultra-compact
  systems)
• These detections confirm that the asymptotic
  frequency is the neutron-star spin frequency

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Globular Cluster Pulsars

• 140 pulsars in 26 clusters
• All recycled, most with P lt 50 ms
• Observed P values are much larger on average
  than for disk MSPs and about half are negative
  acceleration in cluster gravitational potential

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Paulo Freires web page www.naic.edu/pfreire/GC
psr.html
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Two Rich Clusters
47 Tucanae

• 23 MSPs found at Parkes from 1990, 12 binary
• All very short period 2.6 5.8 ms
• Binary periods also short 0.1 2.4 days, all
  circular
• 19 detected as soft X-ray sources

X-ray IDs in 47 Tuc
Terzan 5

• 33 pulsars discovered, all but two at GBT since
  2005
• Much wider range of periods 1.396 ms (716 Hz)
  to 80 ms
• Also wider range of orbital periods 1.7 hours
  to 60 days
• Two highly eccentric systems 0.43 (I) and 0.35
  (J)

(Bogdanov et al. 2006)
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Ionized gas in 47 Tucanae
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• Correlation of DM and P
• P due to acceleration in cluster potential
• Pulsars on far side of cluster have higher DM
• Gas density 0.07 cm-3, about 100 times local
  density
• Total mass of gas in cluster 0.1 Msun

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(Freire et al. 2001)
First detection of intra-cluster gas in a
globular cluster!
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More Diversity!

• SGR/AXPs
• XDINSs
• High-B radio pulsars
• RRATs
• X-ray Gamma-ray pulsars
• SNR associations
• Double NS systems
• Ordinary pulsars!

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Soft Gamma-ray Repeaters (SGRs) and Anomalous
X-ray Pulsars (AXPs)

• SGRs intense bursts of soft gamma-ray emission
  with a modulated tail of weaker emission three
  known
• AXPs sources of modulated X-ray emission ten
  known
• Pulse periods in range 5 12 second no
  evidence for binary motion
• Very high P implies ultra-strong magnetic fields
  (1014 1015 G) and young age (most 1000 years)
  -
• Possible SNR associations for SGRs and one AXP
• X-ray/gamma-ray luminosities much higher than
  spin-down luminosity powered by decay of strong
  magnetic field magnetars
• Pulse timing very irregular glitches seen for
  both AXPs and SGRs

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SGR 1806-20
(Palmer et al. 2005)
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Transient Pulsed Radio Emission from Magnetars
XTE J1810-197 PSR J1808-2024

• 2003 outburst, X-ray pulsations at 5.54 s
• Detected as a radio source at VLA in 2005
• Observed in March 2006 at Parkes strong radio
  pulses detected!
• Pulse shape highly variable
• Very unusual flat spectrum - individual pulses
  detected in GBT obs at 42 GHz!

(Camilo et al. 2006)
1E1547.05408 PSR J1550-5418
Sandro Mereghetti talk!

• X-ray source centred in SNR G327.24 0.13
  tentatively identified as an AXP (Gelfand
  Gaensler 2008) no X-ray pulsations detectable
• Radio observations at Parkes detected strong
  pulsations with P 2.07 s
• Pulse shape highly variable
• P 2 x 10-11 magnetar!

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(Camilo et al. 2007)
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More Diversity!

• SGR/AXPs
• XDINSs
• High-B radio pulsars
• RRATs
• X-ray Gamma-ray pulsars
• SNR associations
• Double NS systems
• Ordinary pulsars!

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X-ray Dim Isolated Neutron Stars (XDINS)

• Very soft and low-luminosity X-ray sources
• Seven known (The Magnificent Seven)
• Blackbody spectrum
• X-ray emission periodically modulated, periods
  in the range 3 12 seconds
• All but one slowing down, P 10-12 10-14
  implying Bs 1013 G
• Optical IDs for most of them
• No radio counterparts and no SNR associations
• Consistent with nearby (50 -300 pc) isolated
  middle-aged neutron stars
• Not-quite magnetars?

RX J1308.62127 (P 10.31 s)
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Roberto Turolla talk!
(Schwope et al. 2005)
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High-B Radio Psrs and RRATs

• Parkes Multibeam Pulsar Survey detected two new
  classes of radio pulsar
• HBRPs are normal radio pulsars with long periods
  (1 7 s) and high P
• Located near AXPs on P P diagram, but very
  different properties
• RRATs have isolated strong radio pulses at
  intervals of minutes to hours
• Careful analysis revealed underlying periodicity
  with P in range 0.4 7 s

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Michael Kramer talk!
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More Diversity!

• SGR/AXPs
• XDINSs
• High-B radio pulsars
• RRATs
• X-ray Gamma-ray pulsars
• SNR associations
• Double NS systems
• Ordinary pulsars!

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High-Energy Pulsars

• Many young pulsars have high-energy non-thermal
  pulsed emission
• For Crab pulsar, pulse components aligned in
  phase, but not for Vela
• For some pulsars, no detectable radio emission,
  e.g. Geminga
• Thermal X-ray emission from NS surface also
  observed
• Emitted from hot polar-cap regions

Andy Shearer Werner Becker talks!
(Becker 2009)
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Fermi Gamma-Ray Observatory
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Fermi MSP Detections

• Fermi searched for pulsed gamma-ray emission
  from MSPs
• Data folded using radio timing ephemerides
• Pulsed emission detected from eight MSPs with
  high E (Abdo et al. 2009)
• Pulse profiles and spectra are remarkably
  similar to those of young pulsars
• Suggests that BLC is important in determining
  gamma-ray properties

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Tuesday mornings talks!
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Supernova Remnant Associations

• About 40 mostly-young pulsars are associated
  with SNR
• Includes five AXP/SGR
• Two associations are for pulsars with very large
  characteristic ages PSR J0821-4300 (Puppis A)
  and PSR J1210-5226 (G296.510.0)
• These are from the Compact Central Objects
  (CCO) group of X-ray sources
• Born with spin periods essentially the same as
  their current period

Pat Slaness talk!
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Pulsar Wind Nebulae

• Relativistic particles and magnetic fields
  ejected from many young pulsars form surrounding
  synchrotron nebula a pulsar wind nebula (PWN)
• Flows are very anisotropic jets and torii
  determine pulsar spin axis!

Thursday mornings talks!
G11.2-0.3 -- PSR J1811-1925
Crab
Vela
Red LE X-ray Green Radio Blue HE X-ray
(Roberts et al. 2003)
Chandra (Wiesskopf et al. 2000 Pavlov et al 2004)
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More Diversity!

• SGR/AXPs
• XDINSs
• High-B radio pulsars
• RRATs
• X-ray Gamma-ray pulsars
• SNR associations
• Binary pulsars
• Ordinary pulsars!

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Types of Binary Pulsars
(Stairs 2004)

• High-mass MS companion
• P medium-long, Pb large, highly eccentric orbit,
  youngish pulsar
• 4 known, e.g. B1259-63
• Double neutron-star systems
• P medium-short, Pb 1 day, highly eccentric
  orbit, pulsar old
• 8 2? known, e.g. B191316, J0737-3039A/B
• Young pulsar with massive WD companion
• P medium-long, Pb 1 day, eccentric orbit,
  youngish pulsar
• 2 known, e.g. J1141-6545
• Pulsars with planets
• MSP, planet orbits from months to years, circular
• 2 known, e.g. B125712
• Intermediate-Mass systems
• P medium-short, Pb days, circular orbit, massive
  WD companion, old pulsar 12 2? known, e.g.
  B065564
• Low-mass systems
• MSP, Pb hours to years, circular orbit, low-mass
  WD, very old pulsar
• 105 known, 55 in globular clusters, e.g.
  J0437-4715, 47Tuc J

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Pulsar period vs Binary period

• MS companion

• Double NS systems

• Intermediate-mass systems, high-mass WD companion

• Low-mass systems, low mass WD companion

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Companion Mass - Pulsar Period

• High-mass systems have little or no recycling
  long pulsar period
• Low-mass systems evolve slowly and are spun up
  to shorter periods
• GC systems dominate low-P, low-mass end
• Different evolution?
• Selection effect?
• Limiting pulsar period?
• Ablation with no accretion?

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DNS Systems

• Formed from high-mass binary systems
• First-born neutron star mildly recycled short
  orbital period
• Second SN doesnt disrupt the system but does
  make it eccentric
• Only one case where both NS are seen as pulsars
  the Double Pulsar
• Second-formed pulsar is long-period but
  relatively young just as expected!
• Great systems for tests of GR!

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PSR J0737-3039A/B Post-Keplerian Effects
R Mass ratio w periastron advance g
gravitational redshift r s Shapiro delay Pb
orbit decay
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GR is OK! Consistent at the 0.05 level!
Marta Burgay talk!
Non-radiative test distinct from PSR B191316
(Kramer et al. 2006)
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More Diversity!

• SGR/AXPs
• XDINSs
• High-B radio pulsars
• RRATs
• X-ray Gamma-ray pulsars
• SNR associations
• Binary pulsars
• Ordinary pulsars!

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Ordinary Pulsars

• Most of the known pulsars (1400)
• Great resource for studies of
• Galactic distribution and evolution of massive
  stars
• Supernovae neutron-star formation, kicks and
  initial spin
• Interactions in relativistic plasmas coherent
  emission mechanisms
• Neutron star interiors glitches and timing
  noise
• Interstellar medium free-electron densities
  and inhomogeneities and Galactic magnetic fields
• Precision astrometry
• Etc, etc.

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Summary

• Pulsars are a very diverse population
• single, binary, rotation-powered,
  accretion-powered, magnetically-powered,
  high-energy, low-energy
• The P P diagram is a great tool for
  distinguishing the different types of pulsar
  the pulsar Hertzsprung-Russell diagram!
• They are wonderful objects which have kept many
  of us fascinated over a lifetime of research!

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Thank you!