Page History

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A single point source: Crab_Pulsar

Using DC1 irfs:

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Here is a FITS image of the count map, summed over energies, used in these fits.

Using DC1 irfs:

• PKS0528+134
  

  Prefactor			Index
  true value	MC dist	KS prob	true value	MC dist	KS prob
  13.65	14.37 +/- 1.70	6.31e-25	-2.46	-2.55 +/- 0.13	1.87e-73

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These analyses use this ROI file.

Crab_Pulsar

DC1 irfs:

Glast 25 irfs:

Image Added

Markov Chain Monte Carlo (MCMC)

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Error estimates for any single fit are given by taking the square root of the diagonal elements of the covariance matrix, which in turn is estimated as the inverse Hessian of the -log-likelihood. Note that the definition of the confidence interval corresponds to a specified change in the log-likelihood along a given direction in parameter space. The estimates obtained from the inverse Hessian are only accurate insofar as the likelihood surface at the local minimum can be represented as a quadratic function of the model parameters.

Using DC1 irfs:

The blue curves are the best-fit parameter values and error estimates obtained from the inverse Hessian represented as Gaussian functions. The red curves are Gaussians fit to the histograms.

PKS 0528+134, Crab, & Geminga

DC1 irfs:

• PKS0528p134
  

  Prefactor			Index
  true value	MC dist	KS prob	true value	MC dist	KS prob
  13.65	14.62 +/- 1.75	3.13e-40	-2.46	-2.52 +/- 0.11	5.13e-40

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• Geminga
  

  Prefactor			Index
  true value	MC dist	KS prob	true value	MC dist	KS prob
  23.29	24.38 +/- 1.74	4.84e-59	-1.66	-1.68 +/- 0.03	4.37e-58

Glast 25 irfs:

• PKS0528p134
  

  Prefactor			Index
  true value	MC dist	KS prob	true value	MC dist	KS prob
  13.65	13.61 +/- 1.21	2.04e-01	-2.46	-2.46 +/- 0.09	1.31e-02

Image Added

• Crab
  

  Prefactor			Index
  true value	MC dist	KS prob	true value	MC dist	KS prob
  27.00	26.97 +/- 1.42	7.77e-01	-2.19	-2.19 +/- 0.05	7.37e-01

Image Added

• Geminga
  

  Prefactor			Index
  true value	MC dist	KS prob	true value	MC dist	KS prob
  23.29	23.39 +/- 1.32	1.96e-01	-1.66	-1.66 +/- 0.03	2.49e-02

Image Added

MCMC results for a single trial

As before, the blue curves are the best-fit parameter values and error estimates obtained from the inverse Hessian represented as Gaussian functions; the red curves are Gaussians fit to the histograms.

Using DC1 irfs:

Extragalactic Diffuse

The ROI file.

Using DC1 irfs:

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