202139 Pulsar Workshop 2009 Beijng 4 202139 Pulsar
- Slides: 55
色 散 2021/3/9 Pulsar Workshop, 2009, Beijng 4
散射 导致脉冲轮廓展宽 2021/3/9 Pulsar Workshop, 2009, Beijng 5
散射 导致脉冲轮廓展宽 2021/3/9 Pulsar Workshop, 2009, Beijng 6
Apparent source diameters S 2021/3/9 d D－d Pulsar Workshop, 2009, Beijng 10
星际介质在空间的分布 β=11/3：Kolmogorov谱 当β≥ 4 时，陡谱模型 ( Bandford & Narayan 1985 ) 内尺度模型（inner scale）(Coles et al. 1987) 2021/3/9 Pulsar Workshop, 2009, Beijng 12
描述DISS动态谱(薄屏模型) Theory prediction of DISS parameters (Thin scattering screen model) β<4 β>4 Kolmogorov谱 (β=11/3)： 2021/3/9 Pulsar Workshop, 2009, Beijng 16
V iss: Pulsar transverse velocities derived from diffractive scintillation spectra： 脉冲星的自行为主导 地球公转速度沿视线 方向曲线变化 忽略介质速度 曲线变化
Gupta (1994): Thin screen, S d D－d 18
=11/3: Kolmogorov fluctuation spectrum =4 2021/3/9 Pulsar Workshop, 2009, Beijng 19
u=s. F/sd : describe the scattering strength s. F is the Fresnel scale at the scattering disk at which the geometric phase difference is 1 radian compared to the direct path; sd is a scale at the observer at which the average phase changes is 1 radian. u<1: weak scattering u>1: strong scattering
2021/3/9 Pulsar Workshop, 2009, Beijng 21
流量变化和调制指数 2021/3/9 Pulsar Workshop, 2009, Beijng 22
For nearby pulsars, the modulation is weak, and DISS will be main effect. For Kolmogorov spectrum, m u 5/6 → m<1 For larger DM, DISS effect is weaker, and m DM-1. But RISS is stronger, with m u-1/3. (u D, so m DM-1/3) 2021/3/9 Pulsar Workshop, 2009, Beijng 23
Oral presentation at IAUC 182 Submitted to CJAA Diffractive scintillation(DISS): Refractive scintillation(RISS): d : short long △ d: narrow wide
闪烁研究 五颗脉冲星在 1540 MHz的长期星际闪烁监测 l 每 9天观测一次，数据 2001年 1月2002年 6月 l 积分2－6 hr，子积分2－4 min l 被观测脉冲星： PSR B 0329+54 PSR B 1823+26 PSR B 1929+10 PSR B 2020+28 PSR B 2021+51 Pulsar Workshop, 2009, Beijng 25 2021/3/9 Wang, N. ; Manchester, R. N. ; Johnston, S. ; Rickett, Bet al. : 2005, MNRAS, 358, 270
PSR B 0329+54 的动态谱 DM＝ 26. 8 pc cm-3 D = 1. 06 kpc 3 hr 的观测 结果： Δtd～ 10 -30 min Δνd ～ 5 -15 MHz 2021/3/9 Pulsar Workshop, 2009, Beijng 26
闪烁二维动态谱 2021/3/9 Pulsar Workshop, 2009, Beijng 28
二维自相关函数 2021/3/9 Pulsar Workshop, 2009, Beijng 29
2021/3/9 Pulsar Workshop, 2009, Beijng 30
Modelling ACFs for PSR B 0329+54 strong scattering thin disk Kolmogorov spectrum
闪烁参数与频率的依赖关系 a. b. c. d. 2021/3/9 Bhat, Rao & Gupta 1999 Gupta, Rickett & Lyne 1994 Stinebring, Fainon & Mckinnon 1996 Our results Pulsar Workshop, 2009, Beijng 32
Daily Observations of Interstellar Scintillation in PSR B 0329+54 Obs: Mar 12— 31, 2004 Wang, N. ; Yan, Z. ; Manchetser, R. N. et al. : 2008, MNRAS
Daily Observations of Interstellar Scintillation in PSR B 0329+54
Modulation indices Observed > prediction !!
闪烁参数的互相关 Cross correlation Wang, N. ; Yan, Z. ; Manchetser, R. N. et al. : 2008, MNRAS, accepted
二次谱 Secondary Spectra, Two dimensional FFT of dynamic spectrum Observing the structure of central image !
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Kolmogorov Spectrum β=3. 67
折射式衍射特征时间 Theory prediction:
Structure Function
TC 93模型 Taylor & Cordes 1993 2021/3/9 NE 2001模型 Cordes & Lazio 2003 a, b Pulsar Workshop, 2009, Beijng 45
闪烁和自行速度的相关性 Harrison & Lyne 1993 2021/3/9 Gupta 1995 Pulsar Workshop, 2009, Beijng 46
2021/3/9 Putney & Stinebring 2006 Pulsar Workshop, 2009, Beijng 47
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Putney & Stinebring 2006
