1 / 11

Pulsar Blind search on DC2 data

Gamma-ray Large Area Space Telescope. Pulsar Blind search on DC2 data. Marcus Ziegler Bill Atwood Brian Baughman Robert Johnson. Basic Idea. Calculate the Fourier-Transform of the time differences of the photon arrival times D t n. take only differences with D t < max_diff

charlotte-walton
Download Presentation

Pulsar Blind search on DC2 data

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. Gamma-ray Large Area Space Telescope Pulsar Blind search on DC2 data Marcus Ziegler Bill Atwood Brian Baughman Robert Johnson

  2. Basic Idea Calculate the Fourier-Transform of the time differences of the photon arrival times Dtn. take only differences with Dt < max_diff max_diff used for DC2 data = 20 000s

  3. Data Selection As input all sources listed in the LATSourceCatalog_v1 were used (=> 380 sources) • James Chiang and Johann Cohen helped to write a Python script to: • Pick a source from the catalog • Select all photons within a 2° radius around the source (no energy dependent cut yet!) • Correct the photon arrival time • Output the data into a text file -> Calculate differences and Perform the FFT

  4. Finding a Pulsar Candidate -> Calculate differences and Perform the FFT Source MRF0035 -> Scan takes about 5s Look for frequency with the highest power Found F0 = 19.371213 1/s DC2 Catalog = 19.371221 1/s

  5. Update on Blind Search Catalog with reprocessed DC2 Data https://confluence.slac.stanford.edu/display/SCIGRPS/Pulsar+Blind-Search+Catalog+from+UC+Santa+Cruz

  6. Scan in Frequency derivative No F1 correction F1 corrected for Crab -> Scan takes about 15 min Found 2x Crab F0 = 59.81810 1/s F1 = -7.5370E-10 -> 1x Crab F0 = 29.90905 1/s F1 = -3.7685E-10 DC2 Catalog F0 = 29.90928 1/s F1 = -3.7638E-10

  7. The most significant sources MRF0054

  8. Light curve for source MRF0168 (Vela) Vela Radio Position Ra = 128.83 Dec = -45.18MRF0168 Position Ra = 128.842 Dec = -45.168701 Light curve: Barycenter time correction for MRF0168 position. Pulsar spin parameter from radio position. Barycenter time correction for MRF0168 position. Optimized pulsar spin parameter for MRF0168 pos. Radio :Ep= 220838550 F0= 11.19723954 F1=-1.5664e-011 F2= 6.26E-22 Optimized :Ep= 220838550 F0= 11.19723929 F1=-1.5578e-011 F2= -2.30E-20

  9. MRF0182 Light Curve (PSR J1638-5226) Epoch_MET = 220838550 f0= 2.9368316221087056 f1= -1.8719736560833061e-014 f2= 4.8 e-021

  10. MRF0054 Light Curve (unknown pulsar with high significance) Epoch_MET = 220838550 f0= 5.8859283239692282 f1= -1.3062300560768745e-012 f2= 1.0 e-021

  11. Summary + Future plans - Scan found 12 Pulsars that were listed in the DC2 pulsar database - The scan found one unknown high significance pulsing source • Things to improve • Use photon selection criteria based on the GLAST PSF • Use a longer integration time (increase the maximum difference) to increase the sensitivity.

More Related