Source list (if applicable) NAME | 1/2FGL NAME | RA | DEC | Notes |
|---|
| | | | |
Data Set | Pass 7
| Event class | Source (evclsmin/max = 2) | Energy range | 100 MeV - 300 GeV | Time interval | UTC_Start -UTC_stop (MET 239557417 - ) | ROI size | 10° | Zenith angle (applied also to gtltcube?) | < 100° | Time cuts filter | DATA_QUAL==1 && LAT_CONFIG==1 && ABS(ROCK_ANGLE)<52 | Science Tools version | v9r21p0 | IRFs P7_V6_Source | Diffuse emission | ring_2years_P76_v0.fits, isotrop_2year_P76_source_v0.txt and limb_2year_P76_source_v0_smooth.txt
| Optimizer and tolerance | Minuit (1e-3 ABS) | Catalog/s | Preliminary 2-year (gll_psc24month_v2.fits) |
Spatial and Spectral AnalysisThe whole analysis is summarized here https://confluence.slac.stanford.edu/pages/viewpage.action?pageId=100515585. HESS data has shown an emission located at RA=284.3°, DEC=2.68°. It remained unidentified untill the detection of PSR J1856+026 in Arecibo PALFA survey (Hessels et al 2008). Here we tested the source for extension using pointlike then gtlike and found no significant extension.  Fig. 1 Residual TS map obtained between 10GeV and 300GeV. Here HESS J1857 is not included in the model. The green contours are those obtained using HESS data (Aharonian et al.,2008). The SED shown a hard spectrum consistent with those of HESS and MAGIC. The best fit between 300MeV and 300GeV yields to the following parameters : Int Flux(100MeV-100GeV) = (5.79 ± 0.75 ± 3.11) X 10^{-9} MeV/cm^2/s Gamma = 1.52 ± 0.16 ± 0.55 With a TS of 38.7.  Systematic Errors AnalysisThe systematics were estimated using the bracketting IRFS, fitting the source galactic background level at +/- 6% of the value of the best fit and the systematics on the shape of the source were computed using a template consistent with the extension derived using HESS data. Broad-Band modellingOther AnalysisHESS 1857 is powered by a young and energetic pulsar, with a gamma-ray efficiency of 3.7% consistent with those observed using HESS data (3.1%) and consistent with the other values observed for the PWNe detected by Fermi. An upper limit on the DC emission pulsar yield to a luminosity < 7.47 X 10^34 erg/s. | 
=Task completed
= To do