2015-11-201 脉冲星研究的现状与展望 乔国俊 北京大学文理学院天文学系...

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脉冲星研究的现状与展望

乔国俊北京大学文理学院天文学系

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脉冲星研究的现状与展望

I. 简介

II. 引力波的检测

III. 新天体的搜寻 IV. 对“磁星”的挑战 V. 广阔的前景、（守时性和导航）

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近近 5050 年来的发现年来的发现 Many discoveries over the Many discoveries over the

past 50yrpast 50yr– 脉冲星脉冲星– 微波背景微波背景– Cosmic EvolutionCosmic Evolution– Dark Matter in galaxiesDark Matter in galaxies– QuasarsQuasars– Jets + Superluminal Jets + Superluminal

motionmotion– 引力辐射间接验证引力辐射间接验证– Aperture SynthesisAperture Synthesis– Cosmic MasersCosmic Masers– Giant Molecular CloudsGiant Molecular Clouds

脉冲星的发现

大约 70% 脉冲星是 Parkes 射电望远镜发现的

脉冲辐射的产生：灯塔模型

谢 谢 !

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PSR 0329+54, P=0.715s

PSR 0833-45, P=89 毫秒

PSR 1937+21, P=1.558 毫秒

PSR 1937+21: P=0.001,557,806,448,872,75(3) 秒

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SGRs,AXPs

High BRadio

Pulsars

MillisecondRadio

Pulsars

V. Kaspi 2006

GRB

Observations of gamma-ray pulsars

8

Pulses at1/10th true rate

Where we are…Gamma Only

MSP

Radio+Gamma

Thompson, astro-ph/0312272 Abdo et al. 2010,ApJS

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脉冲星研究的现状与展望I. 研究历史简介

II. 引力波的检测

1 ）间接检测 2 ）直接检测 3 ）作为引力波源被检测

III. 新天体的搜寻 IV. 对“磁星”的挑战

V 、广阔的前景

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脉冲双星 B1913+16

Hulse & Taylor , 1975

23/4/20 12 Taylor, J.Astrophys.Astr. 1995

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Post-Keplerian Timing Parameters ： PSR B1913+16 Taylor, J.Astrophys.Astr.1995

PSR B1913+16

Weisberg, 2005

Weisberg &Taylor, 2004 astr-ph/0407149

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Weisberg &Taylor, 2004 astr-ph/0407149

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Rate of orbital period change in other gravitational theories, normalized to G.R

Weisberg 2005

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PSR J0737-3039

Kramer et al. 2005,astr-ph/0503386

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PSR J0737-3039 ： the advantages of Double PSR

Lyne 2005

The future fate of B1913+16 in 50 Million Year Timesteps

Size of Sun

Now250 M.Y.

Weisberg 2004

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Double Pulsar J3037-3039

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脉冲星研究的现状与展望I. 研究历史与已有成果

II. 引力波的检测 1 ）间接检测 2 ）直接检测 3 ）作为引力波源被检测

III. 新天体的搜寻 IV. 脉冲星是中子星还是夸克星？ V. 脉冲星 - 磁星 - 伽玛暴

23/4/20 24 Kip,S.T. 2001

大爆炸（年）

0.00001 1

100,000

1,000,000

1,000,000,000 1

5,000,000,000

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Direct Observations of gravitational waves (GW)

The Laser Interferometer Space Antenna (LISA)

Base line:5 million KM, Frequency: 10 － 1 to 10 － 4HzObjects: Massive BH merging …

GW: nanometers

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Direct Observations of gravitational waves (GW)

Laser Interferometer Gravitational-wave Observatory (LIGO) in the USA consisting of two facilities, one at Hanford (WA) and the other at Livingston (LA), hosting two 4-km and one 2-km interferometers

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Possible detections of GW

Possible GW

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Gravitational wave backgroundGravitational wave background

Pulsars=arms of huge gravitational wave Pulsars=arms of huge gravitational wave detectordetectorSearch for spatial patterns in timing residuals!Search for spatial patterns in timing residuals!

Manchester & Lyne, 2003

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Error in Earth Velocity Manchester & Lyne, 2003

Dipole - Opposite sign in opposite directions

Quadrupole -Opposite sign in orthogonal directions

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脉冲星研究的现状与展望

I. 研究历史与已有成果

II. 引力波的检测 1 ）间接检测 2 ）直接检测 3 ）作为引力波源被检测

III. 新天体的搜寻 IV. 脉冲星是中子星还是夸克星？ V. 脉冲星 - 磁星 - 伽玛暴

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Neutro-star/Neutron-star Inspiral

Kip,S.T. 2001

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Binary Black Hole Mergers

Kip,S.T. 2001

23/4/20 34Kip S. Thorne,2001Rogan,et al. astro-ph/0605034

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Gravitational wave background from Big BangGravitational wave background from Big Bang

For example, van Straten et al. (2001) ： over 40months of observing PSR J0437-4715

obtained a residual root-mean-square of only 130 ns

To be improved. ～ 3GHz or higher

DM(dispersion

measure)

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脉冲星研究的现状与展望

I. 研究历史与已有成果

II. 引力波的检测

III. 新天体的搜寻 脉冲星 - 黑洞；亚毫秒脉冲星； IV. 脉冲星是中子星还是夸克星？ V. 脉冲星 - 磁星 - 伽玛暴

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The BH-PSR system

1). Strong gravitational effects; 2). Gravitational microlensing effects (Self-lensing by binary, Gould,1995)

3). Effects of event horizon!4). Particle beam action with the BH

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Stellar mass BH: a compact object with Mass>3Msun

– neutron star neutron degeneracy pressure balances gravity • Oppenheimer

– black hole so massive that nothing can balance gravity

collapse to a point singularity Mass of an invisible star > 3 M⊙ :

black hole !

Supernova

sunNS 3MM

Zhang X.N., 2005

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Difficulties to search for BH-PSR system

Several groups have been searching for BH-PSR system, but It does not find one!

● For shout orbit period binary: it is very difficult to find it! DM, P, Tobt, e,…

●Can we find it at X-ray bands?

Zhang, Qiao, Han, 1998,PABei,16,274

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Accretion induced

collapse (AIC) of WD

=>0.1ms SS

Du,Xu,Qiao,Han,. MN ， 2009

If a pulsar: P<0.5ms? =>

Quark Star!

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Possible test of SS and NS

1. Rotational period: SS can reach sub-millisecond2. Mass-radius. 3. Solid strange star or NS?4. Binding energy of the surface. Bare strange star. Can we take a test from radiation: The difference between vacuum gap and free flow?

23/4/20 43http://chandra.harvard.edu/photo/2002/0211/0211_illustration.pdf

Neutron Stars

v.s.

Quark Stars

Pulsars: Neutron or quark stars?Pulsars: Neutron or quark stars?

“To probe pulsars by GW” http://vega.bac.pku.edu.cn/rxxu R. X. Xu

Milestones in detecting PSRs faster and fasterMilestones in detecting PSRs faster and fasterMilestones in detecting PSRs faster and fasterMilestones in detecting PSRs faster and fasterSp

in

freq

uen

cy

P ~ 1s (1967)

Sub-ms periods (P < 1 ms)

Keplerian frequency (Mass-shedding limit)

Stable axis-symmetric spin (GW radiation)

P = 33ms (1968)

P = 1.6ms (1982)

P = 1.4ms (2006)

PSR 1937

Crab

PSR 1748

XTE 1739P = 0.89ms (2007)?

Only possible in QS model !

“To probe pulsars by GW” http://vega.bac.pku.edu.cn/rxxu R. X. Xu

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脉冲星研究的现状与展望

I. 研究历史与已有成果

II. 引力波的检测

III. 新天体的搜寻 IV. 对“磁星”的挑战 V. 广阔的情景

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反常 X 射线脉冲星（ AXP ） & 软伽玛重复暴（ SGR ）

SGRs,AXPs

High BRadio

Pulsars

RadioPulsars

MillisecondRadio

Pulsars

V. Kaspi 2006

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Basic observations: AXP

spin periodsP: 2-- 12 s , 10 Know Pdot≈ 10-13 to 10-11 s/s, spinning down

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

23/4/20 487-29-2009

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^-13 to 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

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Models

Edot < LX

==

1) Accretion => energy2) B => energy: Magnetar 3) Glitch NS => energy4) Quark star => energy

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对 magnetar 模型的挑战• 射电脉冲星 J1847-0130 ●Anti-Magnetar: PSR J1718-3718 PSR J1852+0040

B ～ 9.4 × 10^13 G ; Lx = 5.3×10^33 erg/s

B ～ 7.4 × 10^13 GX-ray E_dot = 3.0 × 10^32 erg s^−1

Bs = 3.1×10^10 G 强磁场≠》 X-ray 辐射 辐射≠》强磁场 • Radio: XTE J1810–197

AXP 1E 1547.05408 AXP 1E2259+586,

射电 《≠》 弱磁场 B ～ 5.9 × 10^13 G

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对 magnetar 模型的挑战

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AXP XTE J1810–197 :p=5.54 s, B=1.7x10^14 G

Camilo at al. ApJ. 2007,669,561

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AXP XTE J1810–197

Camilo et al.2007,ApJ.659 ， L37

polarimetric profiles over time andfrequency.

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AXP 1E 1547.05408

1.4–8.4 GHz. 8.4 GHz.

Camilo et al.2008,ApJ.

P = 2.069 s, B = 2.2 × 10^14 G,

100% linearly polarized

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几种脉冲星的比较

Rea et al. ,arXiv:1010.2781 56

persistent thermal emission requires an interiorenergy reservoir

total internal magnetic energy

B=1015G, EB=1.7×1047 erg

57

SGR & AXP : Magnetars or Quark Stars?

Mcrust 10^-6 Msun ---10^-5 Msun

58

59

SGR & AXP : Magnetars or Quark Stars?

Mcrust 10^-6 Msun ---10^-5 Msun

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脉冲星研究的现状与展望

I. 研究历史与已有成果

II. 引力波的检测

III. 新天体的搜寻 IV. 对“磁星”的挑战 V. 大设备、大前景

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Conclusion: there is bright future

There is a new chance for us: SKA, FAST▬▬▬► ♣ pulsar black-hole systems ♣ sub-millisecond pulsars ♣ timing highly-stable millisecond pulsars: Gravitational wave background from Big BangGravitational wave background from Big Bang

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The Square Kilometre Array (SKA)

SKA (Square Kilometre Array)• Cradle of Life, • Probing the Dark Ages, • The origin and evolution of Cosmic Magnetism, • Strong field tests of gravity using PSR and BH • Galaxy evolution, cosmology and dark energy,

FAST(The Five-Hundred-meter Aperture

Telescope) -Spectral Lines; -Pulsar Survey; -Pulsars and Gravitational Wave; -Galaxy;-Cradle of Life    Arecibo: effective aperture-200m ， FAST-300m, the sensitivity is 2.25times than Arecibo.

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Simulated Galactic pulsar population Discovered in a SKA survey of the entire sky. 20, 000 pulsars will be found!!!

Cordes et al. astr-ph/0505555

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For a background of SMBH binaries: hc = A f-2/3

.1 s5 years

Expected Regime

1 s, 1 year(Current ability)

.1 s10 years

SKA10 ns5 years40 pulsars

Jenet,F. A., 2005

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Thank you ！

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Double Binary PSR J0737-3039

Kramer et al 2005

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A Pulsar Timing Array

· Accurate timing for PSR at different directions Improve parameters of PSR ▬▬▬► * It can direct test the GW * Background GW of massive BH * PSR timing clock

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Other sources of GW

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AXP XTE J1810–197 ： 1.4G

P^dot 及流量随时间的变化

Camilo et al.2007,ApJ.663 ， 497

23/4/20 70Casares, stro-ph/0612312,