2. Pulsarsand Collapsed Objects Pulsarsand ANDREA POSSENTI INAF – Osservatorio di Cagliari Medicina 1 st MCCT-SKADS Training School 28 September 2007 28 September 2007

3. Outline The absolute beginners - Discovery of the first pulsar (1967) Unveiling the mistery - Discovery of a pulsar associated with the Crab Nebula (1968) Fun for two - Discovery of the binary pulsar PSR B1913+16 (1974) Please put the pulsar in the recycle bin - Discovery of the millisecond pulsar PSR B1937+21 (1982) millisecond pulsar PSR B1937+21 (1982) Not only stellar mates - Discovery of the first planet pulsar PSR B1257+12 (1992) PSR B1257+12 (1992) Fun from two - Discovery of the first double pulsar PSR J0737-3039A/B (2003) PSR J0737-3039A/B (2003) Spinning in the crowds - Discovery of the first millisecond pulsar PSR B1821+24A in a globular cluster (1987) PSR B1821+24A in a globular cluster (1987) Fun for everyone – The present and future of radio pulsar science (from 2007 on…) science (from 2007 on…)

4. Basic References Manchester & Taylor 1977 “Pulsars” Manchester & Taylor 1977 “Pulsars” Lyne & Smith 2005 “Pulsar Astronomy” Lyne & Smith 2005 “Pulsar Astronomy” Lorimer & Kramer 2005 “Handbook of Pulsar Astronomy” Lorimer & Kramer 2005 “Handbook of Pulsar Astronomy” Books Review Articles Rickett 1990, ARAA - Scintillation Rickett 1990, ARAA - Scintillation Science, April 2004 – Neutron Stars, Isolated Pulsars, Binary Pulsars Science, April 2004 – Neutron Stars, Isolated Pulsars, Binary Pulsars Living Reviews articles: ( http://relativity.livingreviews.org/Articles) Living Reviews articles: ( http://relativity.livingreviews.org/Articles) Stairs 2003: General Relativity and pulsar timing Stairs 2003: General Relativity and pulsar timing Lorimer 2005: Binary and millisecond pulsars Lorimer 2005: Binary and millisecond pulsars Will, 2006: General Relativity theory and experiment Will, 2006: General Relativity theory and experiment SKA science: New Astron. Rev. 48 (2004) SKA science: New Astron. Rev. 48 (2004) Cordes et al.: Pulsars as tools Cordes et al.: Pulsars as tools Kramer et al.: Strong-field tests of General Relativiy Kramer et al.: Strong-field tests of General Relativiy

5. Jocelyn Bell Anthony Hewish periodic pulses ! periodic pulses ! P = 1.33 sec P = 1.33 sec dt = 25 ms dt = 25 ms The absolute beginners : discovery of White Dwarfs oscillation ? White Dwarfs rotation ? Neutron Star rotation ? pulsars (1967)

6. Unveiling the mistery: discovery of a pulsar associated with the Crab Nebula (1968) (Staelin & Reifenstein 1968) A period of P = 33 ms, increasing by 36 ns/day ESO-VLT

7. Formed in Type II supernova explosion - core collapse of red giant when the mass exceeds “Chandrasekhar Mass” Diameter 20 - 30 km Mass ~ 1.4 Msun (Lattimer & Prakash 2004) Neutron stars do exist …

8. Energy release ~ 3GM 2 /5R ~ 3 x 10 53 erg ~ 0.1 Mc 2 En.Kinetic of SNR ~ 10 51 erg; 99% of grav energy in ν and anti-ν Asymmetry in neutrino ejection gives kick to NS Measured pulsar proper motions: = 211 km s -1 = 4 /  = 2 for isotropic velocities (Hobbs et al. 2005) Guitar Nebula PSR B2224+65 (Cordes et al. 2003) ~ 30 young pulsars associated with a SNR …and neutron stars/pulsars are born in supernova explosion !

9. Radiopulsars are rapidly rotating and highly magnetized neutron stars anisotropically emitting radiowaves Light-house effect

10. Radio emission mechanism is poorly known yet, but certainly a coherent process ! Source power is very large, but source area is very small Specific intensity is very large Pulse timescale gives limit on source size ~ c  t (Manchester & Taylor 77)

11. The rotational energy pays the energy bill Spin-down Luminosity: Radio Luminosity: Assuming magneto-dipole braking in vacuum : L dipole ~ B 2 surf Ω 4 and by equating L dipole = L sd one can get (Manchester & Taylor 77)

12. Period Time Observed P and  c = 1 P 2 Magnetic dipole energy loss …pulsar Ages and Magnetic fields. B surf  (P P) 1/2..P P..P P. P

13. The observed P and P translates in the fundamental PvsP diagram Galactic disk pulsars ATNF Pulsar Catalogue (www.atnf.csiro.au/research/pulsar/psrcat)....

14. PSR 0329+54 P = 714 ms PSR 0833-45 P = 89 ms … since 1967 until 27 september 2007 … 1765 PULSARs !

15. An immediate use of so many pulsars… …investigating the interstellar medium

16. Dispersion in InterStellar Medium nene Free electrons in ISM t 2  t 1  ( 2 -2  1 -2 ) DM DM = n e dl  L L 0

17.  t DM = 1.2 10  4  3 DM @ 430 MHz  100  s for DM=1 pc/cm 3 δν=1 MHz @ 1400 MHz  3  s for DM=1 pc/cm 3 δν=1 MHz Dispersion smearing Frequency Frequency Frequency time

18. Dispersion & Pulsar Distances For pulsars with independent distances (parallax, SNR assoc, HI absorption) one can detemine mean n e along path. Typical values ~ 0.03 cm -3 From many such measurements can develop model for Galactic n e distribution, e.g. NE2001 model [ Cordes & Lazio 2002] Can then use the model to determine distances to other pulsars

19. A model for DM in the Galaxy [ Taylor & Cordes 1993 ]

20. Smearing due to multi-path scattering  t scatt  1 4

21. A model for t scatt in the Galaxy at 1.0 GHz [ Taylor & Cordes 1993 ]

22. ISM Fluctuation Spectrum (Armstrong et al. 1995) Spectrum of interstellar electron density fluctuations Follows Kolmogorov power-law spectrum over 12 orders of magnitude in scale size (from 10 -4 AU to 100 pc) Mostly based on pulsar observations

23. Faraday Rotation & Galactic Magnetic Field

24. (Han et al. 2005)

25. Fun for two - The discovery of the binary pulsar B1913+16 (1974) P = 59 ms but not a steady slow down

26. time Time residual How one can measure with high precision the pulse period…

27. Pulsar Timing: which other parameters can be determined… Spin parameters: Astrometric parameters: position, proper motion, parallax

28. Pulsar Timing: Binary pulsars 5 Keplerian-parameters: 5 Keplerian-parameters: P orb, a p, e, , T 0 P orb, a p, e, , T 0 Estimate of companion mass if inclination known Estimate of companion mass if inclination known Minimum companion mass for i=90 deg Minimum companion mass for i=90 deg Mass function: Mass function:

29. First possibility of studying relativistic effects on the orbital evolution ! From the determination of the mass function of PSR B1913+16, it appeared probable that the radiopulsar was in a binary system with a second neutron star as a companion

30. The modification in the shape of the orbit periastron precession Pulsar Timing: relativistic pulsars

31. The modifications in the Time Of Arrival (TOA) of the pulses Shapiro Delay

32. Gravitational redshift & time dilation The modifications in the Time Of Arrival (TOA) of the pulses

33. The modification of the shape of the orbits Orbital decay

34. What do we learn observing these relativistic effects (PK parameters) ? Periastron precession Time dilation & gravitational redshift Shapiro delay (amplitude) Shapiro delay (shape) Orbital period decay …where… e orbital eccentricity (observed!) e orbital eccentricity (observed!) P b orbital period (observed!) P b orbital period (observed!) x projected semimajor axis (observed!) x projected semimajor axis (observed!) m p pulsar mass m p pulsar mass m c companion star mass m c companion star mass M = m p + m c total system lagrangian mass M = m p + m c total system lagrangian mass Observing the values of only 2 PK parameters One can measure the pulsar and companion star masses with unrivalled precision Once more than 2 relativistic PK parameters are known, one derives the masses of the 2 bodies and hence predicts the further PK par on the basis of a given Gravity Theory A test for Gravity Theories

35. PSR B1913+16 Pulsar + Neutron Star ( 2 PK par  masses ) Radiative prediction of the General Relativity matches the results of 30 yrs of observations at 0.2% level NOBEL Prize 1993 Taylor & Hulse The measurements done by Russell Hulse & Joe Taylor… The prediction of the General Relativity for P b ….

36. PSR B1534+12 after a dozen yrs of observations non-radiative predictions of GR verified at 0.05% level

37. P = 1.557 ms V = 0.13 c !! Extreme physical conditions occur in millisecond pulsars tangential velocity Please,put the pulsar in the recycle bin Discovery of the millisecond pulsar B1937+21 (1982) [Backer et al. 1982] First promise of putting constraints to the Equation of State for nuclear matter !

38. ATNF Pulsar Catalogue (www.atnf.csiro.au/research/pulsar/psrcat).. How to explain this new group of pulsars ?

39. A newly born pulsar A newly born pulsar has high magnetic field and relatively short spin period 1000 yr death line Hubble time

40. Medium age pulsars A young pulsar evolves relatively fast and slows down The magnetic field of an old pulsar might eventually decay 1000 yr death line Hubble time

41. Died pulsars Slow pulsars with low magnetic fields are not observable as radio sources any more 1000 yr death line Hubble time

42. A died pulsar could be spun up and rejuvenated by an evolving binary companion 1000 yr death line Hubble time

43. A newly born fast spinning pulsar 1000 yr Hubble time death line A recycled pulsar

44. Many Millisecond Pulsars are extremely good clocks The spin period of the original millisecond pulsar PSR B1937+21: P = 0.0015578064924327  0.0000000000000004 sec In this pulsar, after few years of pulse timing, we can predict the time of arrival of pulses within  1  s over 1 year ! A clock stability comparable to the best time standards!!! the best time standards!!!

45. Spinning in the crowds - Discovery of the first millisecond pulsar PSR B1821+24A in a globular cluster (1987) [Lyne et al. 1987] M 28 (NGC 6626 in Sagittarius )

46. … animation of 22 pulsars in 47 Tucanae © K r a m e r a t J B O Pulsars in Globular Clusters

47. Ionized gas in 47 Tucanae 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 M sun. (Freire et al. 2001). First detection of intra-cluster gas in a globular cluster!

48. Millisecond pulsars in other clusters NGC 6266 NGC 6397 NGC6544 NGC 6752 PSR J1701-30 PSR J1740-53 PSR J1807-24 PSR J1910-59 P 5.24 ms 3.65 ms 3.06 ms 3.27 ms P b 3.81 d 1.35 d (eclipse) 0.071 d (1.7 h) 0.86 d M c >0.19 M sun >0.18 M sun >0.009 M sun (10 M Jup ) >0.19 M sun d 6.7 kpc 2.2 kpc 2.5 kpc 3.9 kpc [ D’Amico et al. 2001 ]

49. Probing the central M/L in NGC 6752 [D’Amico et al 2000] [D’Amico et al 2002] 5 pulsars discovered and timed @ Parkes [D’Amico et al 2000] [D’Amico et al 2002] the negative (dP/dt)/P of two MSP located in the central regions is dominated by the cluster potential well a unusually high M/L>6-7 in the central regions of the cluster ~ 3400 M sun of low-luminosity matter in the inner 0.076 pc [D’Amico et al 2002 ] [Ferraro et al 2003 ]

50. An energetic encounter for PSR-A in NGC 6752 [D’Amico et al 2000] [D’Amico et al 2002] PSR-A is the most offset pulsar ever detected in a globular cluster and PSR-C the second most offset [D’Amico et al 2000] [D’Amico et al 2002] [Sigurdsson 2003] [Colpi, Mapelli, Possenti 2004] [Sigurdsson 2003] [Colpi, Mapelli, Possenti 2004] a double black-hole of mass [10-50 M sun ] appears the most probable center of scattering [Colpi, Possenti & Gualandris 2002] both pulsars probably ejected in the halo by a dynamical encounter in the cluster core occurred less than ~ 0.7 Gyr ago [Colpi, Possenti & Gualandris 2002]

51. t int = 54 h! (Hessels et al. 2006) (Ransom et al. 2005) GBT Search of Globular Cluster Terzan 5 5.9h obs with 82  s sampling S min ~ 15  Jy 600 MHz bandwidth at 2 GHz 32 pulsars discovered!! 34 total in cluster (www.naic.edu/~pfreire/GCpsr.html) Two eccentric relativistic binaries; N-star ~ 1.7 M  ? PSR J1748-2446ad - fastest known pulsar! P = 1.3959 ms, f 0 = 716.3 Hz, S 2000 ~ 80  Jy Binary, circular orbit, P b = 1.09 d Eclipsed for ~40% of orbit m c > 0.14 M  PSR J1748-2446ad Interpulse

52. t int = 54 h! (Hessels et al. 2006) (Ransom et al. 2005) GBT Search of Globular Cluster Terzan 5 5.9h obs with 82  s sampling S min ~ 15  Jy 600 MHz bandwidth at 2 GHz 32 pulsars discovered!! 34 total in cluster (www.naic.edu/~pfreire/GCpsr.html) Two eccentric relativistic binaries; N-star ~ 1.7 M  ? PSR J1748-2446ad - fastest known pulsar! P = 1.3959 ms, f 0 = 716.3 Hz, S 2000 ~ 80  Jy Binary, circular orbit, P b = 1.09 d Eclipsed for ~40% of orbit m c > 0.14 M  PSR J1748-2446ad Interpulse

53. Not only stellar mates - Discovery of the first planet pulsar PSR B1257+12 (1992) [Wolcszczan & Frail 1992] A: 3.4 Earth masses, 66.5- day orbit B: 2.8 Earth masses, 98.2- day orbit C: ~ 1 Moon mass, 25.3- day orbit

54. High-mass MS companion: P medium-long, P b large, highly eccentric orbit, youngish pulsar 4 known, e.g. B1259-63 Double neutron-star systems: P medium-short, P b ~ 1 day, highly eccentric orbit, pulsar old 8 + 2? known, e.g. B1913+16 Young pulsar with massive WD companion: P medium-long, P b ~ 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. B1257+12 Intermediate-Mass systems: P medium-short, P b ~days, circular orbit, massive WD companion, old pulsar 12 + 2? known, e.g. B0655+64 Low-mass systems: MSP, P b hours to years, circular orbit, low-mass WD, very old pulsar ~105 known, ~55 in globular clusters, e.g. J0437-4715, 47Tuc J Binary Pulsars Zoology Binary Pulsars Zoology [ Stairs 2004 ]

55. An intriguing zoo for stydying stellar and binary Evolution [ Stairs 2004 ]

56. Fun from two Discovery of the first double pulsar J0737-3039 (2003) [Burgay et al. 2003] [Lyne et al. 2004] © Saverio Ceravolo

57. The discovery of PSR J0737-3039A (April 2003) Binary pulsarBinary pulsar P = 22.7 msP = 22.7 ms Orbital period = 2.4 hr Eccentricity = 0.08Orbital period = 2.4 hr Eccentricity = 0.08 Orbital parameters suggest that the system is relatively massive, probably consisting of two NSsOrbital parameters suggest that the system is relatively massive, probably consisting of two NSs Huge periastron advance (16.88 deg/yr)Huge periastron advance (16.88 deg/yr) [ Burgay, D’Amico, Possenti et al. 2003]

58. Pulsations from PSR J0737-3039B (Oct 2003) The first double pulsar ever known ! [ Lyne, Burgay, Kramer, Possenti et al. 2004] © Howe – ATNF

59. 22.7 ms 1.7 x 10 -18 210 Myr 6 x 10 9 G 1,080 km 5 x 10 3 G 6 x 10 33 erg s -1 301 km s -1 A 2.77 s 0.88 x 10 -15 50 Myr 1.6 x 10 12 G 1.32 x 10 5 km 0.7 G 1.6 x 10 30 erg s -1 323 km s -1 PP SpinDown age B surf R LC B LC E rotational Mean Orbit Velocity B Basic Parameters..

60. The basic parameters Period, SpinDown age and B surf fit with the evolutionary path to the double pulsar systems suggested since long ago [van den Heuvel & deLoore 1975] © Howe – ATNF

61. Mass-mass diagram for J0737-3039A&B © Kramer - JBO

62. Mass function A Mass-mass diagram for J0737-3039A&B © Kramer - JBO

63. Mass function B Mass-mass diagram for J0737-3039A&B © Kramer - JBO

64. Kepler’s 3 rd law To 1PN order, relative separation given by: …so that for “any” theory of gravity to 1PN order: Ratio is independent of strong (self-)field effects! Different to other PK parameters, which all depend on strong-field modified “constants” like G AB which differs from G Newton depending on strong-field effects in theory! Different to other PK parameters, which all depend on strong-field modified “constants” like G AB which differs from G Newton depending on strong-field effects in theory!

65. Mass ratio Mass-mass diagram for J0737-3039A&B © Kramer - JBO

66. Periastron advance GR! Theory dependent! Mass-mass diagram for J0737-3039A&B © Kramer - JBO

67. Grav. Redshift + 2 nd order Doppler GR! Theory dependent! Mass-mass diagram for J0737-3039A&B © Kramer - JBO

68. Shapiro delay in PSR-A arrival times [ Lyne, Burgay, Kramer, Possenti et al. 2004]

69. Shapiro s GR! Theory dependent! Mass-mass diagram for J0737-3039A&B © Kramer - JBO

70. Shapiro r GR! Theory dependent! Mass-mass diagram for J0737-3039A&B © Kramer - JBO

71. Mass-mass diagram for J0737-3039A&B © Kramer - JBO

72. Mass-mass diagram for J0737-3039 @ Feb 2004

73. at June 2007 @ Kramer M B =1.249(1)M  M A =1.338(1)M  Observed shape of Shapiro delay in agreement with GR at 0.05% level 4 independent tests of GR! Mass-mass diagram for J0737-3039 @ Jun 2007

74. What will be feasible to measure: Geodetic Precession Precession periods only ~70 years [ Burgay et al. 2003 ] ~ 4 time shorter than in any other double neutron star: much easier to be detected, thence imposing strong constraints to the geometry of the pulsar beam © Kramer - JBO

75. What will be feasible to measure: Aberration Aberration affects pulse profiles and influences the Time of Arrivals of the pulses. Unfortunately the related PK parameters ( A & B ) are usually absorbed in Roemer delays [ Damour & Deruelle 1986 ] Measuring masses, orbital semi-major axes and eccentricities of two sources in the same binary we should be able to disentangle the aberration contribution!

76. What could be feasible to measure: Neutron Star Structure Total periastron advance to 2PN level: 1PN 2PN Spin A Spin B Neutron star dependent Equation-of-State for the nuclear matter!! [ Damour & Schaefer 1988 ] [ Lattimer & Schutz 2004 ] [ Morrison et al. 2004] A 10% accuracy on I would exclude most EoS

77. The unique occurrence of strong interactions between the energetic flux from A and the magnetosphere of B ( 1 st evidence ) The signal of PSR A displays eclipses for ~20 s at superior conjunction… … and the nature of the occulting medium is dependent on the rotational phase of B The signal of PSR A displays eclipses for ~20 s at superior conjunction… … and the nature of the occulting medium is dependent on the rotational phase of B Superior conjunction Superior conjunction B phase 1.00 B phase 0.75 B phase 0.25 [Breton et al. 2007]

78. The unique occurrence of strong interactions between the energetic flux from A and the magnetosphere of B ( 2 nd evidence ) The intensity and pulse profile of B strongly vary along the orbit … … and during a portion of the phases of high brightness, the radio emission from B matches the ~ 44 Hz electromagnetic pulses arriving from A The intensity and pulse profile of B strongly vary along the orbit … … and during a portion of the phases of high brightness, the radio emission from B matches the ~ 44 Hz electromagnetic pulses arriving from A [McLaughlin et al. 2004]

79. [Burgay, Possenti et al. 2005] Nov04 Jul04 Apr04 Jan04 Sep03 Jul03 High brightess phases of B are changing ! Possibility of removing degeneracy between different models checking their predictions about evolution in a human- scale time !

80. Spin-Powered Pulsars: A Census Number of known pulsars: 1765 Number of millisecond pulsars: 170 Number of binary pulsars: 131 Number of pulsars in globular clusters: 129 Number of extragalactic pulsars: 20 Data from ATNF Pulsar Catalogue, V1.25 (www.atnf.csiro.au/research/pulsar/psrcat; Manchester et al. 2005) [ @ Manchester – ATNF ]

81. Pulsars are excellent clocks, leading to many interesting experiments in astrophysics and fundamental physics: gravity theories, nuclear matter, plasma physics. Pulsars are excellent probes of the interstellar medium and are widely distributed in the Galaxy. A few especially interesting objects with unique properties will probably be found in a large-scale survey. Leads to a better understanding of the Galactic distribution and birthrate of pulsars, of binary and stellar evolution, of their relationship to other objects such as supernova remnants, and of the emission physics. Why searching more pulsars?

82. The sensitivity formula S min  T sys + T sky G N p   t WeWe P  W e   T sys = system noise temperature T sky = sky temperature G = antenna gain N p = number of polarizations  = total bandwidth  t = total integration time P = pulsar period W e = effective pulse width W e = W 2 +  t 2 +  t 2 DM +  t 2 scatt  t = sampling time  t DM = dispersion smearing  t scatt = scattering smearing

83. S min  T sys + T sky G N p   t WeWe P  W e    t DM = 1.2 10  4  3 DM  t scatt  1 4  t samp N ch =  /  …but… S   1.7 …but… N samp =  t/  t samp W e = W 2 +  t 2 samp +  t 2 DM +  t 2 scatt G  large aperture T sky   2.7 (r.a. & dec)  S psr   1.7 0

84. You are here Better use high  t DM   3  t scatt   4 T sky   2.7 Narrow beam  Ok Deep surveys in the disk In order to find many pulsars we have to search large volumes

85. You are here Better use low Large telescope beam ! S psr   1.7 Away from the Galactic plane: Low DM Scattering negligible T sky  30 °K Wide all-sky surveys In order to find many pulsars we have to search large volumes

86. Standard search technique time Radio frequency Power spectrum Fluctuation frequency DM k FFT Pulse phase Integrated pulse profile Folding

87. time Pulse phase Integrated pulse profile Folding s/n If the code picked up the correct apparent pulse repetition period P

88. time Pulse phase Integrated pulse profile Folding s/n If the code picked up a slighlty wrong apparent pulse repetition period P

89. time Pulse phase Integrated pulse profile Folding s/n If the apparent pulse repetition period P is not changing too quickly along the observation, the code can still pick P Knowning exactly how P changes, one can easily recover the pulse profile

90. But if the Doppler acceleration is too high, the signal is not picked up in the fluctuation spectrum ! time Power spectrum Fluctuation frequency FFT

91. time Power spectrum Fluctuation frequency FFT No pulsar suspect ! But if the Doppler acceleration is too high, the signal is not picked up in the fluctuation spectrum !

92. One way to take into account Doppler is to resample the time series according to a trial acceleration time Power spectrum Fluctuation frequency FFT Nr of FFTs = N DM x N acc

93. Coherent (linear) acceleration search [ Camilo et al 2000 ]

94. Segmented FFT procedure helps [ Faulkner, PhD Thesis 2004 ]

95. Segmented vs standard search [ Faulkner, PhD Thesis 2004 ] 9 ms pulsar

96. Dynamic spectrum search [ Chandler, PhD Thesis 2004 ]

97. Phase modulation search [ Ransom et al 2001 ]

98. Phase modulation VS segmented search [ Faulkner, PhD Thesis 2004 ] 9 ms pulsar

99. The choice of the observing parameters of the survey (wide or deep) and the amount of computational capabilities result in a different sampling of evolutionary stage of pulsars and hence of the P-P diagram.

100. Parkes 64 m radiotelescope Multibeam receiver System parameters: 13 beams T sys ~ 25 °K   288 MHz @ 1.4GHz  = 13 x 96 x 3 MHz  = 512 x 0.5 MHz The Parkes multibeam surveys

101. Parkes 64 m radiotelescope Multibeam receiver System parameters: 13 beams T sys ~ 25 °K   288 MHz @ 1.4GHz  = 13 x 96 x 3 MHz  = 512 x 0.5 MHz The Parkes multibeam surveys

102. PM Group: Jodrell Bank, ATNF, Cagliari, Columbia, McGill, … PH Group: Cagliari, Jodrell Bank, ATNF, Columbia, … Swin Group: Swinburne, Caltech PM Survey (PM Group) PH Survey (PH Group) SW Survey (Swinburne Group)

103. [ Manchester et al 2001, Morris et al 2002, Kramer et al 2003 Hobbs et al 2004, Faukner et al 2004, Lorimer et al 2006]

104. [ Manchester et al 2001, Morris et al 2002, Kramer et al 2003 Hobbs et al 2004, Faukner et al 2004, Lorimer et al 2006]

105. [ Manchester et al 2001, Morris et al 2002, Kramer et al 2003 Hobbs et al 2004, Faukner et al 2004, Lorimer et al 2006]

106. Parkes PM = 725 Parkes Swin = 69+25 Parkes PH = 18 Total = 837 Parkes GC search = 12 Parkes 47 Tuc search = 22 a real boom of pulsar discoveries ! Parkes discoveries Radio pulsars in the Catalog:  1765 131 Binaries 170 Millisecond (P<25ms) 26 Vela-like 26 Vela-like 8 Double Neutron star binaries 8 Double Neutron star binaries 1 Double pulsar 1 Double pulsar 129 in 24 Globular Clusters The total score:

107. A Arecibo Alfa Survey at 1.4 GHz  300-500 discoveries in 3-5 yrs ? P Parkes Perseus Arm Survey at 1.4 GHz 15-30 discoveries ? G GBT Pilot Surveys at 350 MHz 30-50 discoveries BT Drift Scan Survey at 350 MHz > > 100 discoveries ? MRT Survey at 610 MHz 5-10 discoveries ? BT Surveys of Globular Clusters at 2.1 GHz > 100 discoveries ? P Parkes Galactic MSP Survey at 1.4 GHz 50-100 MSP discoveries ?

108. Fun for everyone: Pulsar Astrophysics with the SKA (from 200x ) General science case covers lots of topics Galactic probes Galactic probes Extragalactic pulsars Extragalactic pulsars Relativistic plasma physics Relativistic plasma physics Extreme Dense Matter Physics Extreme Dense Matter Physics Multi-wavelength studies Multi-wavelength studies Exotic systems Exotic systems Gravitational physics (SKA KSP) Gravitational physics (SKA KSP) [ Cordes et al. 2004 ] Strong-field tests Strong-field tests of gravity using pulsar & black holes one of five SKA Key Science Projects identified as one of five SKA Key Science Projects

109. Galactic Census with the SKA D Discovery of almost every pulsars in Galaxy: in total  10000-20000 pulsars ~ ~ 1000 millisecond pulsars m more and more Double-Pulsar Systems [ Kramer et al. 2004 ]

110. Galactic Census with the SKA Timing of discovered binary and millisecond pulsars to very high precision: “Find them!” “Find them!” “Time them!” “Time them!” “VLBI them!” “VLBI them!” Not just a continuation of what has been done before Complete new quality of science possible! Complete new quality of science possible! [ Kramer et al. 2004 ]

112. Cosmological Gravitational Wave Background Pulsars discovered in Galactic Census also Pulsars discovered in Galactic Census also provide network of arms of a huge provide network of arms of a huge cosmic gravitational wave detector cosmic gravitational wave detector Perturbation in Perturbation in space-time can be space-time can be detected in timing detected in timing residuals residuals Sensitivity: dimensionless strain Sensitivity: dimensionless strain Pulsar Timing Timing Array Array PTA:

113. Cosmological Gravitational Wave Background With such an array of pulsars, Pulsar timing can detect a stochastic gravitational wave background stochastic gravitational wave background and also: merging massive BH binaries in early galaxy evolution in early galaxy evolutionSources: Inflation Inflation String cosmology String cosmology Cosmic strings Cosmic strings phase transitions phase transitions [ Kramer et al. 2004 ]

114. Cosmological Gravitational Wave Background LISA Pulsars Advanced LIGO Spectral range: nHz only accessible with SKA! Further by correlation: PTA limit: Improvement: 10 4 ! CMB complementary to LISA, LIGO & CMB [ Kramer et al. 2004 ]

115. Astrophysical black holes are expected to rotate BH have spin and quadrupole moment Both can be measured by high precision pulsar timing via relativistic and classical spin-orbit coupling Not easy! It is not possible today! Requires SKA sensitivity! [ Wex & Kopeikin 1999 ] Test Cosmic Censorship Conjecture & No-Hair Theorem! [ Kramer et al. 2004 ] The last not prohibited dream: a pulsar orbiting a Black Hole (200?)

116. Happy hunting, folks !!!