...
Model | RA(°) | DEC(°) | Semi Major Axis (°) | Semi Minor Axis (°) | Pos.Ang.(°) |
283,990 | 1,355 | 0,300 | 0,190 | 327,000 | |
Pass 6 | 284.015(+/-0.004) | 1.392(+/-0.005) | 0.335(+0.117 -0.086) | 0.207 (+0.023 -0.021) | 330+/- 25 |
Pass 7 | 284.000(+/-0.006) | 1.374(+/-0.006) | 0.332(+0.109/-0.079) | 0.205 (+0.021/-0.017) | 327 +/-22 |
...
The best fit using gtlike provided the following parameters and statistical errors alpha = 3.5 +/- 0.2, beta = 0.6 +/- 0.1, Eb ? 1.2 GeV, and N_0 = (3.1 +/- 0.5) X 10^{-12} photons/MeV/cm^2/s.
HESS 1857+026 Morphology above 10GeV
We made an analysis of the morphology of HESS 1857+026 above 10GeV. Three hypotheses were tested : point source, gaussian and disk.
Search for pulsed emission
A.LYNE, B. STAPPERS and C.ESPINOZA kindly provided us timing solution of PSR J1856+0245 which powers HESS J1857+026.
Marie-Helene searched for pulsation concidering 43 pulsars in 3° around the HESS position but found no pulsed emission from PSR J1856+0245. H-Test <<2. 
Fig.6 TS map above 10GeV using Pass6_V11. HESS J1857 is not included in the model. white contours are those obtained using HESS data. Cyan : Pulsars monitored by radio-telescopes. Green : Other pulsars (from the ATNF database)
Only one good candidate was found : PSR J1856+0113 located in W44 : 
Fig. 7. Light curves and H-Test obtained looking at PSR J1856+0113 above 50 MeV and 300MeV.
HESS 1857+026 Morphology above 10GeV
To avoid any contamination from other sources or diffuse emission from the Galactic plane we tested for extension above 10 GeV. All the sources previously announced were taken into account (18 months -> Pass 6, 2FGL +1 ->Pass 7)No significant extension was found as can be seen in the following table. The delta show that we do not detect any extension of the source.
Hypothesis | Point | Gaussian | Disk | ||
|---|---|---|---|---|---|
TS | 33.38 | 41.35 | 42.21 | ||
?TS | - | 7.97 | 8.83 |
|
Table 2. TS and Loglike
...
-48201.50
...
-48197.55
...
-48197.98
...
found above 10GeV for a point source, a gaussian and a Disk. Pass 6 analysis.
Hypothesis | Point | Gaussian | Disk |
|---|---|---|---|
TS | 14.6 | 20.1 | 18.3 |
?TS | - | 5.5 | 3.7 |
Table 3Table 2. TS and Loglike found above 10GeV for a point source, a gaussian and a Disk. Pass 7 analysis.
Analysis | RA(°) | DEC(°) |
|---|---|---|
HESS | 284.3 | 2.68 |
Pass 6 | 284.28 | 2.74 |
Pass 7 | 284.31 | 2.76 |
Table 4. Fited positions.
Fig. 48. Excess TSMap of a 10° * 10° roi around HESS 1856+026.Fig. 5 Zoom of the previous TS map with a factor of 5. The green square represent an 2° * 2° roi and the green contours are those of HESS sourceResidual TSMap in which HESS J1857 is not fitted. Pass 6 analysis. + HESS contours
Fig 9. Residual TSMap in which HESS J1857 is not fitted. Pass 6 analysis. + HESS contours. Green crosses represents 2FGL sources.
Bibliography :
(1) Abdo et al., Science, 327, 1103-1106, 2010