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19 July 2011

The following analysis of Cassiopeia A was done using pointlike with a 15 degree ROI and a LogParabola fit. The energy range used in the analysis is 100MeV to 100GeV, although the SEDs are shown only in the range of 1-100GeV since there is no reliable measure of their flux at lower energies.

Home directory: /u/st/ariel/cassa2FGL

The galactic diffuse model used: ring_2year_P76_v0.fits

The isotropic spectra models used: isotrop_2year_P76_source_v0.txt (For front and back events), isotrop_2year_P76_source_v0_front.txt (For front only events), isotrop_2year_P76_source_v0_back.txt (For back only events)

Catalog used: gll_psc_v04.fit

Instrument response function: P7SOURCE_V6

SEDs	1st half of time window MET Start = 239557417 seconds (2008-08-04T15:43:37) Stop = 284206459 seconds (2010-01-03T10:14:19)	2nd half of time window MET Start = 284206459 seconds (2010-01-03T10:14:19) Stop = 328855431 seconds (2011-06-04T04:43:49)	Full time window MET Start = 239557417 seconds (2008-08-04T15:43:37) Stop = 328855431 seconds (2011-06-04T04:43:49)
Front only events	Norm : 1.37e-13 Index : 2.15 beta : 0.0935 E_break : 6.78e+03 Ph. Flux : 3.68e-08 (DERIVED) En. Flux : 5.77e-11 (DERIVED) TS: 237.1	Norm : 4.51e-10 Index : 1.75 beta : 0.0394 E_break : 98.9 Ph. Flux : 5.28e-08 (DERIVED) En. Flux : 7.58e-11 (DERIVED) TS: 264.5	Norm : 5.83e-12 Index : 1 beta : 0.237 E_break : 659 Ph. Flux : 1.26e-08 (DERIVED) En. Flux : 4.2e-11 (DERIVED) TS: 508.4
Back only events	Norm : 1.15e-07 Index : 2.19 beta : 1.21e-08 E_break : 12.6 Ph. Flux : 1.05e-07 (DERIVED) En. Flux : 1.08e-10 (DERIVED) TS: 116.2	Norm : 9.31e-26 Index : 2.19 beta : 1.16e-09 E_break : 2.14e+09 Ph. Flux : 9.15e-08 (DERIVED) En. Flux : 9.11e-11 (DERIVED) TS: 94.629082599	Norm : 9.13e-11 (Failed fit) Index : 1.16 beta : 0.16 E_break : 163 (Failed fit) Ph. Flux : 3.43e-08 (DERIVED) En. Flux : 4.99e-11 (DERIVED) TS: 213.2
Front and back events	Norm : 3.29e-11 Index : 1.65 beta : 0.0904 E_break : 378 Ph. Flux : 3.96e-08 (DERIVED) En. Flux : 5.75e-11 (DERIVED) TS: 330.2	Norm : 4.02e-14 Index : 2.14 beta : 0.0285 E_break : 1.15e+04 Ph. Flux : 5.83e-08 (DERIVED) En. Flux : 7.51e-11 (DERIVED) TS: 358.6	Norm : 2.26e-12 Index : 1.53 beta : 0.23 E_break : 1.6e+03 Ph. Flux : 1.56e-08 (DERIVED) En. Flux : 4.28e-11 (DERIVED) TS: 676.030199235

The following counts maps were also done in pointlike.

Counts maps	1st half of time window MET Start = 239557417 seconds (2008-08-04T15:43:37) Stop = 284206459 seconds (2010-01-03T10:14:19)	2nd half of time window MET Start = 284206459 seconds (2010-01-03T10:14:19) Stop = 328855431 seconds (2011-06-04T04:43:49)	Full time window MET Start = 239557417 seconds (2008-08-04T15:43:37) Stop = 328855431 seconds (2011-06-04T04:43:49)
Front only events
Back only events
Front and back events

Observations

1) The analysis was done with separate isotropic spectra files for the front and back of Fermi to check to see if both observation sets overlapped on a particular source.

2) The analysis was also done with two different time windows to try and get a statistical check on any of the features observed in the SEDs for the full timeframe.

20 July 2011

Between 100MeV and 1GeV there appears to be significant variation in the flux observed by the Fermi satellite depending on which type of events (Front, back, or both) are used in producing the SEDs. The SEDs, using close to three years of observation data, are as follows:

Full time window MET Start = 239557417 seconds (2008-08-04T15:43:37) Stop = 328855431 seconds (2011-06-04T04:43:49)	Back only events	Front only events	Both
	Norm : 6.25e-12 Index : 0.976 beta : 0.24 E_break : 635 Ph. Flux : 1.3e-08 En. Flux : 4.33e-11 TS: 412.8	Norm : 6.25e-12 Index : 0.976 beta : 0.24 E_break : 635 Ph. Flux : 1.3e-08 En. Flux : 4.33e-11 TS: 412.8	Norm : 6.25e-12 Index : 0.976 beta : 0.24 E_break : 635 Ph. Flux : 1.3e-08 En. Flux : 4.33e-11 TS: 412.8