Difference between revisions of "Fermi LAT Main OP313"
Davidsanchez (talk | contribs) |
Davidsanchez (talk | contribs) |
||
| Line 154: | Line 154: | ||
[[File:LSTGTISED_OP313_LogParabola.png|thumb|centre|400px|Fermi-LAT SED in LST GTI (December 2023]] | [[File:LSTGTISED_OP313_LogParabola.png|thumb|centre|400px|Fermi-LAT SED in LST GTI (December 2023]] | ||
| + | |||
| + | |||
| + | === January === | ||
Revision as of 14:17, 19 February 2024
The Fermi LAT analysis has been performed on a large time scale to derive a long-term light curve and run a Bayesian block analysis to defined bocks of observation
Contents
Parameters
RA = 197.6324 degrees Dec = 32.3547 degrees Start = 715617241.0 MET (s) Stop = 727281241.0 MET (s) ROI = 10.0 degrees E min = 100.0 MeV E max = 300000.0 MeV E min ext = 50.11872336272722 MeV E max ext = 598578.6944906638 MeV IRFs = P8R3_SOURCE_V3 evclass = 128 evtype = 3
Long term Fermi-LAT Light curve
This plot is the Fermi-LAT LC with the final bayesian block description. The block are given in the table after
In the High state, I used bins of around 12 hours, 1 day in the Mid state and 3 days in the low state
| Date | MET start | MET stop | N bins |
| high | 722300909 | 722984524 | 16 |
| 723877193 | 724823786 | 22 | |
| Mid | 722104724 | 722300909 | 2 |
| 722984524 | 723877193 | 10 | |
| 724823786 | 725266164 | 5 | |
| 726394414 | 726767552 | 4 | |
| Low | 716277470 | 722104724 | 22 |
| 725266164 | 726394414 | 4 | |
| 726767552 | 727281241 | 2 |
SEDs
For each SED, a powelaw and a logparabola model were tested
Low
The spectrum is best described by a logparabola with a TS = 7
Decorrelation energy : 4.14e+02 MeV TS : 1356.0178181243173 norm : 108.86 +/- 6.16 [ -6.05, + 6.27 ] 1e-12 alpha : 2.03 +/- 0.08 [ -0.08, + 0.07 ] 1e+00 beta : 0.08 +/- 0.04 [ -0.03, + 0.04 ] 1e+00 Eb : 414.00 1e+00
Mid
The spectrum is best described by a logparabola with a TS = 8 Decorrelation energy : 4.66e+02 MeV TS : 2584.4997249984517 norm : 238.16 +/- 11.60 [ -11.40, + 11.80 ] 1e-12 alpha : 1.79 +/- 0.05 [ -0.06, + 0.05 ] 1e+00 beta : 0.06 +/- 0.02 [ -0.02, + 0.02 ] 1e+00 Eb : 466.00 1e+00
High
The spectrum is best described by a logparabola with a TS = 80
Decorrelation energy : 5.66e+02 MeV TS : 8991.45 norm : 467.06 +/- 14.19 [ -13.97, + 14.41 ] 1e-12 alpha : 1.57 +/- 0.03 [ -0.03, + 0.03 ] 1e+00 beta : 0.10 +/- 0.01 [ -0.01, + 0.01 ] 1e+00 Eb : 564.00 1e+00
All in a SED
This plot show the same 3 SED but in one plot
Sanity checks
I ran a Fermi-LAT analysis in each block to see differences within each block
Fermi-LAT analysis on the LST GTI
The Fermi-LAT pipeline allow to run an analysis based on pre-defined GTI. This has been done using the LST observation time. For this the December and January data set were separated since they correspond to 2 different flux states.
GTI correspond to the LST observation time after data selection, plus or minus 1 hour
December
- GTI definition :
723873640.4679999 723885814.544 723961205.0 723972636.3690003 724045627.3670001 724058152.8549998 724131722.0 724143939.893 724218276.9149997 724231900.1550002 724304640.2630002 724318201.9809997 724390555.44 724404422.1790001 724477321.222 724491352.339 724563718.779 724577641.8430002 724650067.315 724663888.9659998
- results
The spectrum is best described by a logparabola with a TS = 8
Decorrelation energy : 6.36e+02 MeV TS : 485.58040012843094 norm : 319.83 +/- 42.96 [ -37.51, + 0.00 ] 1e-12 alpha : 1.47 +/- 0.14 [ -0.15, + 0.14 ] 1e+00 beta : 0.15 +/- 0.06 [ -0.06, + 0.07 ] 1e+00 Eb : 631.00 1e+00
