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UW “Source Detection” Status. Disclaimer: We are not really in the source-detection game: this is not a good method for finding seeds Toby Burnett, for Sean Robinson. What we have. New, simple PSF, Aeff parameterization Multiple point source generator Input: specified logN/logS distribution

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Uw source detection status

UW “Source Detection” Status

Disclaimer: We are not really in the source-detection game: this is not a good method for finding seeds

Toby Burnett, for Sean Robinson

UW source detection status Sep 29, 2004 - T. Burnett


What we have
What we have

  • New, simple PSF, Aeff parameterization

  • Multiple point source generator

    • Input: specified logN/logS distribution

  • Multichromatic continuous wavelet transform (MCWT)

    • Projection of a set of photon positions and energies

    • A peak is an estimator of:

      • Signal size

      • Source position

      • Significance (with separate estimate of total)

  • One-year AGN study

    • Use model of Stecker & Salamon for AGN population

    • Quick MC to generate photons according to PSF.

    • Estimate number of sources, sensitivity

UW source detection status Sep 29, 2004 - T. Burnett


New psf parameterization
New PSF parameterization

Two parameters: : scale factor, corresponds to rms for gaussian : exponent

UW source detection status Sep 29, 2004 - T. Burnett


Example fits
Example fits

UW source detection status Sep 29, 2004 - T. Burnett


Multiple point source generator
Multiple point source generator

  • Behaves like a standard flux source

  • Input: logN/logS function

UW source detection status Sep 29, 2004 - T. Burnett


Multichromatic continuous wavelet transform mcwt
Multichromatic Continuous Wavelet Transform (MCWT)

Continuous

Multichromatic

UW source detection status Sep 29, 2004 - T. Burnett


Estimators from peak of mcwt
Estimators from peak of MCWT

  • Value: the rate

  • Position

  • Significance (from auxiliary measurement of background)

UW source detection status Sep 29, 2004 - T. Burnett


Wavelet estimator performance
Wavelet estimator performance

Background to signal ratio

The wavelet sigma is ~10% worse than full ML.

UW source detection status Sep 29, 2004 - T. Burnett


Agn population model
AGN population model

  • The inspiration: this plot from Stecker and Salamon.

    • Data points:EGRET identified and presumed AGN population

    • Solid line: their model

    • Dashed line: -3/2 power

    • GLAST sensitivity: from AO document

  • Question: is observed high-lattitude diffuse consistent with undetected AGN’s?

UW source detection status Sep 29, 2004 - T. Burnett


Ingredients in the calculation
Ingredients in the calculation

  • The logN/logS function from S&S, input to the special source generator.

  • Constant fluxes, with fixed spectral index 2.15.

  • The instrument model (PSF, Aeff)

  • Only front section used

  • One year observation

UW source detection status Sep 29, 2004 - T. Burnett


Sean s result detect 2673
Sean’s result: detect 2673

UW source detection status Sep 29, 2004 - T. Burnett


Conclusions outlook
Conclusions, outlook

  • This wavelet technique provides robust and accurate estimation of point sources

  • Multiple AGN generation according to model works fine

  • Have a preliminary estimate of number of AGNs a 1-year survey would see, and corresponding limit on remaining diffuse

  • Both tools need refinement, documentation

UW source detection status Sep 29, 2004 - T. Burnett


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