Table 1: Numerical summary $^\dagger ~ ^\ddagger$ for the VHE and E>100 MeV sources in the W 28 region including positional and spectral information.
  Best fit position (J2000.0)     Spectral analysis  
Name RA [deg] Dec [deg] 1 $\sigma_{\rm src}$ [deg] 2S [$\sigma $] (evts) 3 k $^4 \Gamma$ 5 L
HESS J1801-233 270.426 $\pm$ 0.031 -23.335 $\pm$ 0.032 0.17 $\pm$ 0.03 +7.9 (281) 7.50 $\pm$ 1.11 $\pm$ 0.30 2.66 $\pm$ 0.27 1.5
HESS J1800-240A$^\S$ 270.491 $\pm$ 0.001 -23.962 $\pm$ 0.001 0.15 +6.0 (180) 7.65 $\pm$ 1.01 $\pm$ 0.50 2.55 $\pm$ 0.18 1.5
HESS J1800-240B$^\S$ 270.110 $\pm$ 0.002 -24.039 $\pm$ 0.009 0.15 +7.8 (236) 7.58 $\pm$ 0.90 $\pm$ 0.15 2.50 $\pm$ 0.17 1.4
HESS J1800-240C 269.715 $\pm$ 0.014 -24.052 $\pm$ 0.006 0.02 $\pm$ 0.15 +4.5 (71) 4.59 $\pm$ 0.89 $\pm$ 0.20 2.31 $\pm$ 0.35 0.8
HESS J1800-240$^{\S\S}$ 270.156 $\pm$ 0.044 -23.996 $\pm$ 0.022 0.32$^{\rm RA}$ $\pm$ 0.05 +10.3 (652) 18.63 $\pm$ 1.85 $\pm$ 1.20 2.49 $\pm$ 0.14 3.6
      0.17 $^{\rm Dec}$ $\pm$ 0.03        
GRO J1801-2320 270.360 $\pm$ 0.150 -23.340 $\pm$ 0.150 - +13.2 3.35 $\pm$ 0.52 2.16 $\pm$ 0.10 480.0
$\dagger$ VHE photon spectra are derived from a region of radius $\theta = \sqrt{0.1^2+\sigma_{\rm src}^2}$ centered on each source's position unless otherwise indicated.
$\ddagger$ In spectra, a function ${\rm d}N/{\rm d}E = k E^{-\Gamma}$ ph cm-2 s-1 TeV-1 is fitted. E is in TeV units (HESS data); GeV units (EGRET data).
1. Fitted intrinsic source size (Gaussian std. dev.).
2. Statistical significance and excess events in brackets; for HESS sources using Li & Ma (1983); for EGRET sources given by $S=\sqrt{T_{\rm s}}$ for $T_{\rm s}$ defined by Mattox et al. (1996).
3. For HESS sources: $\times 10^{-13}$ ph cm-2 s-1 TeV-1 at 1 TeV (with statistical and systematic errors); For EGRET sources: $\times 10^{-2}$ ph cm-2 s-1 GeV-1 at 1 GeV (with statistical errors).
4. Only statistical errors indicated. Systematic error is estimated at $\pm$0.2.
5. Luminosity $\times 10^{33}$ erg s-1 at 2 kpc (0.3 to 3 TeV for HESS; 0.04 to 6 GeV for EGRET).
$^\S$ Due to cross contamination between components A & B, a fixed value of $\sigma_{\rm src}= 0.15^\circ$ estimated visually from Fig. 1 was used.
$^{\S\S}$ Spectrum extracted from a 0.8 $^\circ \times 0.6^\circ$ elliptical region encompassing all components A, B, C, and matching the size of the corresponding molecular cloud.

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