1 / 24

IS PULSAR B0628-28 REALLY AN EXCEPTION?

IS PULSAR B0628-28 REALLY AN EXCEPTION?. Cuilan Qiao Mentor:Pro. Xiangdong Li Dec.7, 2005. OUTLINE. 1 Introduction 2 Data analysis for spin-powered pulsars 3 Theoretic discussion 4 Conclusion. 1 Introduction. Observation of pulsar B6028-28 Chandra:

nicholas-sherman
Télécharger la présentation

IS PULSAR B0628-28 REALLY AN EXCEPTION?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. IS PULSAR B0628-28 REALLY AN EXCEPTION? Cuilan Qiao Mentor:Pro. Xiangdong Li Dec.7, 2005

  2. OUTLINE • 1 Introduction • 2 Data analysis for spin-powered pulsars • 3 Theoretic discussion • 4 Conclusion

  3. 1 Introduction • Observation of pulsar B6028-28 Chandra: ► Was observed twice:first on Nov.4,2001 and again on 2002 Mar.25 for 2000 and 17000s respectively;1.141s exposures. ► position is XMM-Newton: ► Was observed on 2004 Feb. 28 for a total on time of 48ks;47ks exposures. ► position is

  4. Properties of pulsar B6028-28 ► The longest period radio pulsar detected in X-rays (P=1244ms). ► The Chandra data yielded a luminosity 2 orders of magnitude greater than what is expected for a spin-powered pulsar(logLx=30.34). ► From Tepedelenlioglu et. al ,APJ astro-ph/0505461

  5. Old pulsars • Other 41 spin-powered pulsars(Possentiet al.2002) MSPs Giminga-like

  6. Vela-like Crab-like

  7. 2 Data analysis for spin-powered pulsars • Clustering analysis-with Nearest Neighbor method in matlab ► Zscore-----data standardization ► Pdist-----calculate space between two objects by Euclidean distance ► Squareform-----Euclidean distance matrix ► Linkage-----nearest neighbor method ► cluster-----cluster data ► find----- find elements of every group ► Dendrogram-----draw clustering graph

  8. 42 spin-powered pulsars clustering diagrams • clustering result with logτ and logLx

  9. 2 clustering result with logdP/dt、logτ and logLx

  10. clustering result with logP、logdP/dt、logτand logLx

  11. clustering result with logP、logdP/dt、logτ、logLsd and logLx

  12. clustering result with logP and logLx

  13. clustering result with logLsd and logLx

  14. Fitting • 42 spin-powered pulsars fitting graphes with errorbars logLx~logτ B0628-28

  15. B0628-28 logLx~logLsd

  16. 42 spin-powered pulsars fitting parameter

  17. 3 Theoretic discussion • Model ---a one-zone shocked wind model (Chevalier,2000) • The central pulsar generates a highly relativistic,particle-dominated wind that passes through the medium in the supernova remant,forming a shock front. The electrons and positrons in the wind acruire a power-law energy spectrum in the shock front and radiate synchrotron emission in the sownstream region. The basic simplification is that the emitting region can he treated as one zone One-zone model that does not attemp to account for the spatial structrue of the nebulae.

  18. 3 Theoretic discussion

  19. 4 Conclusion • 42 spin-powered pulsars can be grouped into 2 groups; • Lx~τ-2,Lx~Lsd; • Pulsar B5028-28 is under the groups of spin-powered pulsars.

  20. Thanks!

More Related