qiao

Slide1: 

Radio pulsars & Anomalous X-ray pulsars(AXP) Qiao G.J. Astronomy Dept. of Peking Univ.

Slide2: 

Radio pulsars & Anomalous X-ray pulsars(AXP) 1.Radio pulsar ☆ Basic observational facts & derived parameters ☆ Radiation models for radio emission ☆ Radiation models for Gamma-ray emission 2.Anomalous X-ray pulsar(AXP) ☆ Basic observations & Comparison ☆ Accretion Models of AXP & Test of obs. ☆ Accretion models for radio pulsars

Slide3: 

Radio pulsars: observational facts ● Basic observational facts ☆ Individual and integrated pulse profiles ☆ Polarization ☆ Mode changing ☆ Drifting sub-pulses ● Basic parameters ☆ P,Pdot,DM: observed ☆ ,B: derived

Pulsar radiation : 

Pulsar radiation

Slide5: 

脉冲星的个别脉冲 和平均脉冲

Slide6: 

Interstellar Dispersion Ionised gas in the interstellar medium causes lower radio frequencies to arrive at the Earth with a small delay compared to higher frequencies. Given a model for the distribution of ionised gas in the Galaxy, the amount of delay can be used to estimate the distance to the pulsar. P--period DM--dispersion measure

Slide7: 

“S” shape PA & Obs.

Slide8: 

Mean pulse shapes and polarisation Lyne & Manchester (1988) P.A. Stokes I Linear Stokes V

Slide9: 

Drifting subpulses PULSE LONGITUDE Drifting subpulses Taylor et al. (1975) Backer (1973)

The strength of the magnetic field: 

The strength of the magnetic field Pacini 1968: Ostriker&Gunn1969:  Xu & Qiao, 2001, ApJL, 561,L85

Slide11: 

Characteristic age of pulsars 

Slide12: 

Radio pulsars & Anomalous X-ray pulsars(AXP) 1.Radio pulsar ☆ Basic observational facts & derived parameters ☆ Radiation models for radio emission ☆ Radiation models for Gamma-ray emission 2.Anomalous X-ray pulsar(AXP) ☆ Basic observations & Comparison ☆ Accretion Models of AXP & Test of obs. ☆ Accretion models for radio pulsars

Slide13: 

Radio pulsars: models for radio emission ☆ The magnetosphere of neutron stars ☆ Inner vacuum gap(RS model) ☆ Space charge limited flow ☆ Inverse Compton Scattering model(ICS model)

Slide14: 

th=3/2 nkT g=GMNSmnh/r2 h=3kTr2/(2GMNS)1 cm  Pulsars: without atmosphere When: T=106 k m=mp, r=RNS=10 km

Slide15: 

Magnetospere of pulsars Goldreich & Julian, 1969,ApJ,157,869 

Slide16: 

The magnetosphere of a NS For Crab Pulsar:  Goldreich & Julian, 1969,ApJ,157,869

Slide17: 

Mono-generator For the Earth: For the Sun: For Crab Pulsar:

Inner gap: 

Inner gap Ruderman & Sutherland ,1975,ApJ

Slot gap model: 

Slot gap model Arons,J. 1983, ApJ

Outer gap: 

Outer gap

Slide21: 

Magnetospere of pulsars Am--mass of ion, Z-charge of ion Outer gap, 1 Space charge limited flow Inner gap

Slide22: 

Radio pulsars: models for radio emission ☆ The magnetosphere of neutron stars ☆ Inner vacuum gap(RS model) ☆ Space charge limited flow ☆ Inverse Compton Scattering model(ICS model)

Slide23: 

● Gamma-ray OBS. Of Radio Pulsars

Slide24: 

Emission beams in RS model

Slide25: 

Frequency Dependence of Mean Pulse Profile Phillips & Wolsczcan (1992) Geometry of magnetic pole model

Slide26: 

Radio pulsars: model for radio emission ☆ The magnetosphere of neutron stars ☆ Inner vacuum gap(RS model) ☆ Space charge limited flow ☆ Mode changing & death line ☆ Inverse Compton Scattering model(ICS model)

Slide27: 

脉冲星的模式变化

Slide28: 

Zhang,Qiao,Lin,Han, 1997, ApJ Mode changing

Slide29: 

Qiao,Xue,Zhang,Xu,Ye,Wang,2003

Slide30: 

ω=2γ2ω0(1-βCosθi) Assumption 2: The low frequency wave can Propagate near the surface Qiao & Lin, 1998,A&A

ICS Model: emission beams----Core +cones: 

ICS Model: emission beams----Core +cones Qiao ， 1992,

Slide32: 

ICS: shift of emission beams Different emission location→shift of the emission beams Qiao & Lin, 1998,A&A

Slide33: 

Polarization of integrated pulse in ICS V—circular poln L—Linear poln I—Total Intensity Position angle Xu et al. ApJ.2000

Slide34: 

Obs. & ICS : Type IIa ICS Obs. Qiao,Liu,Zhang & Han, 2001,AA Phillips & Wolsczcan (1992)

Slide35: 

Obs. & ICS: Type Ib Obs. ICS Qiao,Liu,Zhang & Han, 2001 Cramer 1994, AAs

Slide36: 

Obs. & ICS: Type IIb Obs. Qiao,Liu,Zhang & Han, 2001,A & A Cramer 1994, AAs

Slide37: 

Accelerators: Inner vacuum gap (Ruderman & Sutherland 1975) requiring high binding energy of charges on stellar surface Drifting sub-pulses Xu,Qiao Zhang, 1999,ApJL,522,L112 Deshpannde & Rankin, 1999,ApJ, 524,1008

Slide38: 

Radio pulsars & Anomalous X-ray pulsars(AXP) 1.Radio pulsar ☆ Basic observational facts & derived parameters ☆ Radiation models for radio emission ☆ Radiation models for Gamma-ray emission 2.Anomalous X-ray pulsar(AXP) ☆ Basic observations & Comparison ☆ Accretion Models of AXP & Test of obs. ☆ Accretion models for radio pulsars

Pulsar Gaps: 

Pulsars are broad-band emitters (gamma-ray, X-ray, optical, radio) Pulsars must be particle accelerators Two preferred acceleration regions: --- Polar cap region --- Outer gap region Pulsar Gaps

Slide40: 

Muslimov & Harding, 2003 Slot gap model

Slide41: 

Cheng et al. (1986); Romani (2000) Rotating neutron-star model: magnetospheric gaps Inner (polar cap) gap Outer gaps Regions of particle acceleration! W.B = 0

Slide42: 

Dyks & Rudak,2003 Caustic Model

Slide43: 

The problems of the current models for Gamma-rays ● The problems ☆ Polar cap models:   200 ☆ Outer Gap models: Gamma-ray cut off ? ● Where the problems come from? ☆ Polar cap models: did not taking the null surface into account ☆ Outer Gap models: can not correlated with the inner gap ● The way to resolve these problems Inner vacuum gap + Outer gap model ● What can we get? ☆ To result the difficulties in the models ☆ To get a model for radio + Gamma rays

Multiple acceleration model (WA model): 

Multiple acceleration model (WA model) Qiao,Lee,Wang,Xu, 2003

Slide45: 

Observations & theories of MA model MA model Observations

Observations and theories of AXP: 

Observations and theories of AXP Basic observations &Comparison : AXP( Anomalous X-ray Pulsars) SGR: Soft Gamma-ray Repeaters X-ray Pulsars, Radio Pulsars; Accretion Models of AXP & Test of obs. Accretion models for radio pulsars

Basic observations: AXP: 

Basic observations: AXP  spin periods P: 6-- 12 s  Pdot 10-11 s/s Large timing noise  Edot LX  spin down time scales: 103—105 yr  very soft X--ray spectra  lack of bright optical counter parts  SNR Mereghetti, et al. astroph/0205122

Basic observations: SGR: 

Basic observations: SGR  super-outbursts  1044reg/s (low-energy gamma-ray and X-ray bursts)  Observations for AXP:  spin periods P: 5-- 8 s  Pdot  10-11 s/s  Large timing noise  Edot  LX  soft X--ray spectra  secular spin down on time scales: 103—105 yr  lack of bright optical counter parts  SNR Mereghetti, et al. astroph/0205122

Observations and theories of AXP: 

Observations and theories of AXP Basic observations: AXP( Anomalous X-ray Pulsars) SGR: Soft Gamma-ray Repeaters Comparison: Radio Pulsars; X-ray Pulsars Accretion Models of AXP & Test of obs. Accretion models for radio pulsars

High mass X-ray binaries: 

High mass X-ray binaries

Low mass X-ray binaries: 

Low mass X-ray binaries

Comparison: Radio Pulsars/X-ray pulsars: 

Comparison: Radio Pulsars/X-ray pulsars  Radio Pulsars: 0.0016s-8.5s Pulsars in HMXB: 0.069s--1400s SGR: 5s--8s AXP: 6s---12s

Compression between AXP and other objects: 

Compression between AXP and other objects

CCO & DTN: 

CCO & DTN

AXP: Lx  Edot : 

AXP: Lx  Edot

Lx & E_dot: 

Lx & E_dot (Guseinov et al. 2002).

Radio pulsars, AXP & SGR : 

Radio pulsars, AXP & SGR Camilo et al.2000,ApJ

Pulsars with High-B: 

Pulsars with High-B Camilo et al.2000,ApJ

PSR(1814-1744)--AXP(2259+586): 

PSR(1814-1744)--AXP(2259+586) Bradio BAXP

Observations and theories of AXP: 

Observations and theories of AXP Basic observations: AXP( Anomalous X-ray Pulsars) SGR: Soft Gamma-ray Repeaters Comparison: Radio Pulsars; X-ray Pulsars Accretion Models of AXP Test of obs. Accretion models for radio pulsars

X-ray Bursts from AXP 1E 1048 : 

X-ray Bursts from AXP 1E 1048

Magnetars & Disks: 

Magnetars & Disks

Evolutionary tracks in the P-Pdot diagram: 

Evolutionary tracks in the P-Pdot diagram (1) B12 = 1.8, M0,dot = 5 10^28 g /s (2) B12 = 2.8, M0,dot = 1 10^28 g /s (3) B12 = 5.5, M0,dot = 5 10^27 g /s (4) B12 = 8, M0,dot = 3.2 10^28 g /s (5) B12 = 6, M0,dot = 2 10^27 g /s Eksi & Alpar,astroph/0309029

Period evolution of AXPs: 

Period evolution of AXPs (1) B12 = 1.8, M0,dot = 5 10^28 g /s (2) B12 = 2.8, M0,dot = 1 10^28 g /s (3) B12 = 5.5, M0,dot = 5 10^27 g /s (4) B12 = 8, M0,dot = 3.2 10^28 g /s (5) B12 = 6, M0,dot = 2 10^27 g /s Eksi & Alpar,astroph/0309029

Test of observations: 

Test of observations NS: different B B: obs. ?(Sanwal et al. 2002; Xu et al.2002) Disk: Observed ? Near-IR obs. & Opt obs. (Hullemant et al.2000,2002) Disk: precession?(Qiao et al,2003) NS or Strange star ? SGR: disk+cloud(Xu et al.2001)

CYCLOTRON ABSORPTION LINES: 

CYCLOTRON ABSORPTION LINES Bignami et al. 3002,Nature 423,725

CCO & DRQNS: 

CCO & DRQNS Line: 0 .7, 1.4 and 2.1 keV(Bignami et al.Nature,2003) electron: Bl=61010G, ; proton: Bl=1.6 1014 G (Sanwal et al. 2002) Bp,dp/dt=3×1012G,(Xu et al.2002)

Spectrum line of AXP : 

Spectrum line of AXP Line: 8.1 keV(astrph/0302490, 0309402) electron:B= 9 × 1011G proton: B=1.6 1015 G

IR Observations of AXP: 

IR Observations of AXP IR Observation astroph/0204233(1708) astroph/0209599(1048) Hulleman,et al. ApJ,2001,(2259) Hulleman,et al 2000(0142) Durant et al. astr-ph/0309801(0124;1048)

Optical Observations of AXP: 

Optical Observations of AXP Opt. Observation Hulleman,et al. Nature,2002,,(2259) Hulleman,et al Nature, 2000(0142) Durant et al. astr-ph/0309801(0124;1048)

X-ray Bursts from AXP 1E 1048 : 

X-ray Bursts from AXP 1E 1048 Mereghetti et al.astroph/0205122

Accretion models for AXP: 

Accretion models for AXP Basic observations: AXP( Anomalous X-ray Pulsars) SGR: Soft Gamma-ray Repeaters Comparison: Radio Pulsars; X-ray Pulsars Accretion Models of AXP Accretion models for radio pulsars

Optical pulsations from the AXP 4U0142161: 

Optical pulsations from the AXP 4U0142161 Kern & Martin, 2002,Nature,417,527 The pulsed fraction of optical light (27 per cent) is five to ten times greater than that of soft X-rays  Magnetar there are no detailed models predicting the opt. emission from magnetars. Crab, Vela:LX /Lopt < 103-4 similar to 4U0142 

Precession observations of radio pulsars : 

Precession observations of radio pulsars Crab :astr-ph/0303369(103 yr) Vela: Sedrakian et al. 1999,ApJ. 524,241(104 yr) PSR 1642-03: Shabanova et al. 2001, ApJ. 552,321(3.4 Myr) PSR 1842-11: Stairs et al. Nature,2000,406,484(0.11 Myr)

Fallback Disk  --> precession? : 

Fallback Disk --> precession?

Free Precession of a Radio Pulsar : 

Free Precession of a Radio Pulsar B1828–11: Systematic timing residuals Periods of 1000, 500 and 250 days Pulse shape and torque correlated Stairs et al. 2000

Free Precession of a Radio Pulsar: 

Free Precession of a Radio Pulsar BUT: Free precession is not expected in case of pinned vortices in super-fluid interior!

An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL): 

An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL)

An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL): 

The gravitational potential The precession angular velocity The simplification An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL)

An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL): 

An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL)

Are there any other observational facts related to the fullback accretion disk? : 

Are there any other observational facts related to the fullback accretion disk?

Arrival time residuals for 1E 1048.1  astr-ph/0011368: 

Arrival time residuals for 1E 1048.1 astr-ph/0011368

Conclusion and discussion 1. Magnetar or disk: ?  same observational fact with different point of view !!! 2.More theoretical works and observations are needed.3. Our point of view: periods:5—10s , spin down age  SNR age & “free precession” and some other observations  are favorable to accretion model    : 

Conclusion and discussion 1. Magnetar or disk: ? same observational fact with different point of view !!! 2.More theoretical works and observations are needed. 3. Our point of view: periods:5—10s , spin down age  SNR age & “free precession” and some other observations are favorable to accretion model

At present no one can present an important evidence to distinguish these two models !!! Can we find a way to present an important evidence to distinguish these two models?: 

At present no one can present an important evidence to distinguish these two models !!! Can we find a way to present an important evidence to distinguish these two models?

PSR(1847-0130)--AXP(2259+586): 

PSR(1847-0130)--AXP(2259+586) A challenge to magnetar model: Bradio > BAXP

B1847-0130 > Bmagnetar: 

B1847-0130 > Bmagnetar  AXP  Radio pulsar Mcloughlin et al.2003, ApJL

Slide89: 

Thank you！

Slide90: 

Thank you！