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Searching Potential X-Ray Counterparts of GeV Sources J1837-0610

Searching Potential X-Ray Counterparts of GeV Sources J1837-0610. 盧亭霓 Lu Ting-Ni 2006.11.21. Outline. Introduction - Science purpose - GeV J1837-0610 Data - download data - data reduction - analysis Results Conclusion Reference. Introduction. Science purpose

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Searching Potential X-Ray Counterparts of GeV Sources J1837-0610

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  1. Searching Potential X-Ray Counterparts of GeV Sources J1837-0610 盧亭霓 Lu Ting-Ni 2006.11.21

  2. Outline • Introduction - Science purpose - GeV J1837-0610 • Data - download data - data reduction - analysis • Results • Conclusion • Reference

  3. Introduction • Science purpose - try to find next γ-ray pulsar. • Gev J1837-0610 - an unidentified γ-ray source. - with a X-ray counterpart candidate AX J1837.5-0610 (Roberts M. S. E. et al, 2001, ApJS, 133, 451-456).

  4. Roberts M. S. E. et al, 2001, ApJS, 133, 451-456

  5. Roberts M. S. E. et al, 2001, ApJS, 133, 451-456

  6. Introduction • GeV J1837-0610 Roberts M. S. E. et al, 2001, ApJS, 133, 451-456

  7. Data • Download data - constrain: a. center offset < 25 arcmin. b. exposure time > 10 ksec.

  8. Data • Download data

  9. Data • Data reduction - abandon ROSAT data: cannot find any point-like source near the area with RA~18h37m, Dec~-06h10m.

  10. The green circle is the region with center at (RA, Dec)=(18:37:29.000,-6:09:38.000), radius=90arcsec.

  11. Data • Data reduction - abandon SIS data of ASCA: there’s only FAST mode data can be used to do timing analysis, but the FAST mode data isn’t offered by the archieve data. - abadon LECS data of Beppo-SAX: the exposure time is too short. Also, there’s not any point-like source near the area with RA~18h37m, Dec~-06h10m

  12. Data • Data reduction

  13. Data • Data reduction - filter region and determine position: a. ASCA: *The point spread function (PSF) of GIS alone is a Gaussian with a FWHM of 0.5×(5.9/E〔keV〕) arcmin. *The main energy band of the photons is at between 2.3keV and 7.1keV.

  14. The corresponds of the PI channel of ASCA to the energy band.

  15. Data • Data reduction - filter region and determine position: b. BeppoSAX: Originated from the cookbook for BeppoSAX NFI spectral analysis V1.2

  16. Originated from the cookbook for BeppoSAX NFI spectral analysis V1.2

  17. The corresponds of the PI channel of BeppoSAX to the energy band.

  18. Data Data reduction - filter region and determine position: besides, the region need to encloses the most photons of source but least photons of background.

  19. Data • Data reduction - filter energy: a. ASCA: http://heasarc.gsfc.nasa.gov/docs/asca/gis_sis_effective_area.html

  20. Data • Data reduction - filter energy: b. BeppoSAX: Originated from the cookbook for BeppoSAX NFI spectral analysis V1.2

  21. Data

  22. Data • Data reduction - barycentric time correction: to make the time on satellite be accordance with the time on earth.

  23. Exampleof ASCA data (1998-04-02) Left: before doing barycentric time correction; Right: after doing barycentric time correction.

  24. Data • Analysis - a. epoch folding. b. Zm2-Test. c. H-Test.

  25. Data

  26. Data Trial periods at which H value is larger than about 35

  27. Data • Analysis - search counterpart periods of data: use the condition that the age of a pulsar should be larger than 1000 years to find possible periods in other data (which is observed at different time).

  28. Result Tentative counterpart periods in ASCA and BeppoSAX data Periods are reported with digits accurate to about one tenth of corresponding Fourier widths. The random probability (r.p.) is for one single trial only.

  29. Result Properties of the six tentative counterpart periods Periods are reported with digits accurate to about one tenth of corresponding Fourier widths. Here used the period that has larger H value. The Τc is the characteristic age and equals to P/2P’. S.P.E. is the spin down energy .

  30. Comparison between the six tentative counterpart periods and the high energy pulsar

  31. Conclusion • Age: the age of Crab is about 1300 years, but P1, P4 and P6 is young than Crab. • Period: the period of existent γ-ray pulsar is at the scale of millisecond, but P6 has period of 2 seconds. • S.P.E.: the S.P.E. of existent γ-ray pulsar is about 1034~1038 (erg s-1), but the S.P.E. of P1 is about 1039 (erg s-1). • Compare with existent γ-ray pulsar, I thought P2 is more possible period within the six case, and infered from above that Gev J1837-0610 may be a crab-like pulsar.

  32. Reference • Roberts M. S. E., et al, 2001, ApJS, 133, 451-456 • Gottfried Kanbach, 2002, 2002nsps. Conference • P. M. Wallace and N. J. Griffis, et al, 2000, APJ, 540: 184-191 • M. Tavani, et al, 1997, APJ, 479: L109-L112 • Takanori Sakamoto, 2001, 2001ASPC, Vol. 251 • http://www.atnf.csiro.au/research/pulsar/psrcat/ • http://heasarc.gsfc.nasa.gov/docs/asca/gis_sis_effective_area.html

  33. THANK YOU VERY MUCH~~~!!

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