JAN20SUM.TXT

SUMMARY OF JAN 20'05 GAMMA ANALYSES


~Jan 20: Preliminary survey of Jan 17,19 and 20 events
            - some aspect gaps on 20th. 
            - no obvious map peaks in others at 2218-2228


Jan 24: For jan 20 event...
            remaining aspect gap 065446-070458 compromises preliminary maps


Jan 25: JAN20-LC1.ps ==> appropriate time interval Jan 20 0645-0702 at 2.2
                            but use 06:44 - 07:02 to include bremsstahlung <-------------
                             retained data as JAN20-LC1.SAV  
        JAN20-NC1.ps ==> good 6+9RN peak at               [803,274] +- 4.7
                            9R peak alone ==> peak at       [820,230] +- 22.5
                            837+418 6+9R counts between 2218-2228
        Note 2-sigma discrepancy between 6+9R and 9R location
        Also peak/grm ==> discrepancy between 6R and 9R imaged flux.

        Background determined between 2230-2280 ==> 208+169 6+9R counts
        Using SIM_BPSTAX as a new test to see if peaks are significant.
        Also explored possible new significance tools.


Jan 28: Investigated ULD mapping ==> inadequate statistics (s/n estimate ~0.6)


Feb 7: event_list_maker, 0627-0727, 150-15000 keV--> HESSI_DATA/JAN20_EVENTLIST_REAR.FITS
     
       High energy continuum imaging, 1000-7000 keV, 0644-0654
            9R--> excellent image, s/n=19.9 !, peak at  [822.4, 275.9] +- 4.1 
            6R --> no peak consistent with this....

        3500-7000 --> good 9R peak at                   [822.0, 273.3] +- 8.6
        1500-2000 --> good 9R peak at                   [826.8, 267.2] +- 8.1
                        (but no dominant 6R peak)
        7000-15000 --> no dominant 9R peak

        250-500   --> good 9R peak at                   [834.8, 260.7] +- 2.0
                    and good 6R peak at                 [818.9, 251.9] +-1.7
                NOTE DIFFERENCE BETWEEN 6R AND 9R LOCATIONS !!
                Also, 6R visibility was relatively low - possible NS elongation ?
            5-9RU --> clear double source at [816.5, 272.5], [819.5,236.5] with
                            possible weak source at [852.5, 266.5]
                            saved as JAN-20IM1.ps

Mar 26: Tried 511 line imaging, 5-9RU, 0644-0654, 508-514 kev --> no apparent source
            Retry with natural weighting --> weak source at a bizarre location
            6-9RN --> peak, but at [758,224] which makes no sense and is not consistent
                            from subcoll to subcoll.  Result saved as JAN20-IM2.ps
            7-9RN --> a peak at similar location, which was cleaned (although this did not
                            do much good)             Result saved as JAN20-IM3.ps



May 10: Wrote nc_stax_plot.pro to compare 2.2 statistics.  Noted that July 23 stax seemed low
            and Jan 20 seemed to have extra D6 counts at 2.2 MeV.
        Also summarized results to date.

        CONCLUSIONS / STATUS:
            250-500 keV, dominated by eb shows double (possible triple) source.
                            Weighted centroid of individual sources is ~[825, 256]
                            9R is located at [834.5, 260.7] +-2.0
                            This is displaced by ~11 arcsec from calculated centroid, in
                                a limbward direction, consistent with an albedo contribution.
                                NEED TO COMPARE SUMMED FLUXES TO CONFIRM THIS HYPOTHESIS.
                            1000-7000 keV continuum seems to favour the northerly source component.
                                    at the 4 sigma level of significance.
                            Note the discrepancy between the 2.2 9R peak and 1000-7000 9R peak

        NEXT:   * Understand the 'extra' counts in D6 at 2.2 MeV
                * Understand the bizarre results at 511 keV 
                * Understand the discrepancy between 9R 2.2 and 9$ 1000-7000 keV locations.
                * Further explore use of 9R to view the nuclear continuum location
                * Cross check with EIT/TRACE
                * Try dividing 2.2 9R peak by energy and time.
                * Try 1000-7000 keV with D6R



May 12 - Jun 3:  Extensive analyses in preparation for Locarno.  See 5/11, 5/13 emails to RPL for status.

Nov 22:

Nov 23: Use GAMMA_LC_GEN to create JAN20-LC3.SAV (889kB) with light curve/spectral matrix from 06:40-07:10

        Use GAMMA_S2N_PRED to optimize s/n in 9R 2.2 line.  Optimizing a mix of statistical s/n and ratio of
            source to bkgd ==> use 2215-2231 keV and 06:44-06:54 UT.

        Use GAMMA_AVTIME_PLOT to plot average arrival time vs energy.  NC peak delay is quite evident, but
            delays also extend toward higher energies and at lower energies.  Is this due to unintentional
            inclusion of background or due to energy-dependent fluxes?

            Could resolve this by a light curve of 9R visibility amplitudes.

---------------------------------------------

March 16, 2005 SUMMARY OF 511 LINE IMAGING

    Mar 26'05 - Initial attempts with 5-9RU, 6-9R and 7-9R, 0644-0654 UT. 508-514 keV. center=[800,280]
                    Results in JAN20-IM2,3.  Source, if any was way off to the SE.

    May 29'05 - Retry with 5-9RN, 0656-0726 UT. 508-514 keV. Peak, if any, was at odd location.
                    9R,6R, 5-9FN, 9F -> no really convincing peak

    May 31'05 - Consider GS flux estimates, which predict s/n of 3.2,3.4 for rear, front.

    THEREFORE DISREGARD 511 IMAGING UP TO THIS POINT SINCE NON-OPTIMIZED TIME, ENERGY.

    Jun 1'05  - Use JAN20LCinterpol to optimize s/n ==> use 500-520keV and 0644-0726.
                   9R -> peak at [834,223]=-16" S/N=5.0. JAN20-IM5
                   Tried 9F, but without /use_rate switch.

    Jun 2'05  -  9F with /use_rate, 500-520, 0644-0726. -> peak at [848,253]+-15", s/n=5.4.  JAN20-IM6.ps,.fits