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

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）

近 50 年来的发现 Many discoveries over the past 50yr Many discoveries over the past 50yr – 脉冲星 – 微波背景 –Cosmic Evolution –Dark Matter in galaxies –Quasars –Jets + Superluminal motion – 引力辐射间接验证 –Aperture Synthesis –Cosmic Masers –Giant 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

PSR , P=0.715s PSR , P=89 毫秒 PSR , P=1.558 毫秒 PSR : P=0.001,557,806,448,872,75(3) 秒

SGRs, AXPs High B Radio Pulsars Millisecond Radio Pulsars V. Kaspi 2006 GRB

Observations of gamma-ray pulsars

8 Pulses at 1/10 th true rate Where we are…

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

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

脉冲双星 B Hulse & Taylor, 1975

Taylor, J.Astrophys.Astr. 1995

Post-Keplerian Timing Parameters ： PSR B Taylor, J.Astrophys.Astr.1995

PSR B Weisberg, 2005

Weisberg &Taylor, 2004 astr-ph/

Weisberg &Taylor, 2004 astr-ph/

Rate of orbital period change in other gravitational theories, normalized to G.R Weisberg 2005

PSR J Kramer et al. 2005,astr-ph/

PSR J ： the advantages of Double PSR Lyne 2005

The future fate of B in 50 Million Year Timesteps Size of Sun Now 250 M.Y. Weisberg 2004

Double Pulsar J

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

Kip,S.T. 2001

大爆炸（年） ,000 1,000,000 1,000,000,000 15,000,000,000

Direct Observations of gravitational waves (GW) The Laser Interferometer Space Antenna (LISA) Base line:5 million KM, Frequency: 10 － 1 to 10 － 4 Hz Objects: Massive BH merging … GW: nanometers

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

Possible detections of GW Possible GW

Gravitational wave background Pulsars=arms of huge gravitational wave detector Search for spatial patterns in timing residuals! Manchester & Lyne, 2003

Error in Earth Velocity Manchester & Lyne, 2003 Dipole - Opposite sign in opposite directions Quadrupole -Opposite sign in orthogonal directions

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

Neutro-star/Neutron-star Inspiral Kip,S.T. 2001

Binary Black Hole Mergers Kip,S.T. 2001

Kip S. Thorne,2001 Rogan,et al. astro- ph/

Gravitational wave background from Big Bang For example, van Straten et al. (2001) ： over 40months of observing PSR J  obtained a residual root-mean-square of only 130 ns To be improved. ～ 3GHz or higher DM(dispersion measure)

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

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

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 Zhang X.N., 2005

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

Accretion induced collapse (AIC) of WD => 0.1ms SS Du,Xu,Qiao,Han,. MN ， 2009 If a pulsar: P Quark Star!

Possible test of SS and NS 1. Rotational period: SS can reach sub-millisecond 2. 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?

Neutron Stars v.s. Quark Stars Pulsars: Neutron or quark stars? “To probe pulsars by GW” R. X. Xu

Milestones in detecting PSRs faster and faster Spin frequency 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 1739 P = 0.89ms (2007)? Only possible in QS model ! “To probe pulsars by GW” R. X. Xu

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

反常 X 射线脉冲星（ AXP ） & 软伽玛重复暴（ SGR ） SGRs, AXPs High B Radio Pulsars Radio Pulsars Millisecond Radio Pulsars V. Kaspi 2006

Basic observations: AXP  spin periods  P : s, 10 Know  P dot ≈ to s/s, spinning down  Large timing noise  E dot < L X  spin down time scales: 10 3 —10 5 yr  very soft X--ray spectra  lack of bright optical counter parts  SNR Mereghetti, et al. astroph/

Basic observations: SGR  super-outbursts  reg/s (low-energy gamma-ray and X-ray bursts)  Observations for AXP:  spin periods P: s  P dot ≈ 10^-13 to s/s  Large timing noise  E dot <L X  soft X--ray spectra  secular spin down on time scales: 10 3 —10 5 yr  lack of bright optical counter parts  SNR Mereghetti, et al. astroph/

Models E dot < L X ==  1)Accretion => energy 2)B => energy: Magnetar 3)Glitch NS => energy 4)Quark star => energy

对 magnetar 模型的挑战 射电脉冲星 J ● A nti-Magnetar: PSR J PSR J 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 AXP 1E , 射电 《 ≠ 》弱磁场 B ～ 5.9 × 10^13 G

对 magnetar 模型的挑战

AXP XTE J1810–197 : p= 5.54 s, B=1.7x10^14 G Camilo at al. ApJ. 2007,669,561

AXP XTE J1810–197 Camilo et al.2007,ApJ.659 ， L37 polarimetric profiles over time and frequency.

AXP 1E –8.4 GHz. 8.4 GHz. Camilo et al.2008,ApJ. P = s, B = 2.2 × 10^14 G, 100% linearly polarized

几种脉冲星的比较

Rea et al.,arXiv:

persistent thermal emission requires an interior energy reservoir total internal magnetic energy B=10 15 G, E B =1.7×10 47 erg 57

SGR & AXP : Magnetars or Quark Stars? M crust  10^-6 M sun ---10^-5 M sun 58

59 SGR & AXP : Magnetars or Quark Stars? M crust  10^-6 M sun ---10^-5 M sun

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

Conclusion: there is bright future Gravitational wave background from Big Bang 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 Bang

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.

Simulated Galactic pulsar population Discovered in a SKA survey of the entire sky. 20, 000 pulsars will be found!!! Cordes et al. astr- ph/

For a background of SMBH binaries: h c = A f -2/3.1  s 5 years Expected Regime 1  s, 1 year (Current ability).1  s 10 years SKA 10 ns 5 years 40 pulsars Jenet,F. A., 2005

Thank you ！

Double Binary PSR J Kramer et al 2005

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

Other sources of GW

AXP XTE J1810–197 ： 1.4G P^dot 及流量随时间的变化 Camilo et al.2007,ApJ.663 ， 497

Casares, stro-ph/ ,