Table 4: Best-fitting models and X-ray fluxes at Earth for the brightest early-type stars in Westerlund 2. For each parameter, the lower and upper limits of the 90% confidence interval (derived from the ERROR command under XSPEC) are noted as indices and exponents, respectively. The normalisation factors are defined as $10^{-14}\int n_{\rm e} n_{\rm H} {\rm d}V/4\pi D^2$, where D, $n_{\rm e}$ and $n_{\rm H}$ are respectively the distance to the source (8 kpc), the electron and proton density of the emitting plasma. Abundances were fixed to solar except for the WR stars (for more details, see text).
Star Obs $N_{\rm int}^{\rm H}$ $N^{\rm H}$ ${\it kT}$ Norm $\chi^2_{\nu}$ (d.o.f.) $f_{\rm X}^{\rm abs}$ $L_{\rm X}^{\rm unabs}$
    1022 cm-2 1022 cm-2 keV 10-3 cm-5   10-13 erg cm-2 s-1 1033 erg s-1
WR20a Obs 1 1.13 $\rm 1.53_{1.20}^{1.89}$ $\rm0.87_{0.24}^{1.04}$ $\rm 1.57_{0.98}^{16.7}$      
      $\rm 5.74_{1.89}^{14.6}$ $\rm 1.96_{0.87}^{6.38}$ $\rm 1.07_{0.29}^{10.7}$ 1.15 (33) 4.51 4.95
WR20a Obs 2 1.13 $\rm 1.63_{1.40}^{1.92}$ $\rm0.42_{0.32}^{0.50}$ $\rm 4.96_{3.04}^{10.9}$      
      $\rm 5.48_{3.92}^{7.27}$ $\rm 1.30_{1.16}^{1.52}$ $\rm 2.61_{1.69}^{3.87}$ 1.26 (97) 4.10 4.88
WR20a Obs 3 1.13 $\rm 1.93_{1.62}^{2.24}$ $\rm0.35_{0.29}^{0.43}$ $\rm 9.60_{4.43}^{21.6}$      
      $\rm 3.28_{2.40}^{4.53}$ $\rm 1.55_{1.39}^{1.75}$ $\rm 1.88_{1.44}^{2.53}$ 1.02 (119) 5.04 5.69
WR20b Obs 1 1.04 $\rm 1.23_{0.67}^{1.88}$ $\rm 3.62_{2.44}^{8.05}$ $\rm0.26_{0.18}^{0.38}$ 1.24 (24) 2.06 1.88
WR20b Obs 2 1.04 $\rm 2.18_{1.67}^{2.86}$ $\rm 2.47_{1.94}^{3.13}$ $\rm0.41_{0.32}^{0.58}$ 1.30 (35) 1.97 1.77
WR20b Obs 3 1.04 $\rm 1.03_{0.67}^{1.48}$ $\rm 5.21_{3.70}^{6.72}$ $\rm0.22_{0.18}^{0.28}$ 1.97 (38) 2.29 2.05
MSP18 Obs 1 0.88 $\rm0._{0.}^{0.18}$ $\rm 3.24_{2.53}^{4.18}$ $\rm0.31_{0.28}^{0.36}$ 0.92 (18) 2.88 3.70
MSP18 Obs 2 0.88 $\rm0._{0.}^{0.13}$ $\rm 3.30_{2.81}^{3.64}$ $\rm0.27_{0.26}^{0.30}$ 1.10 (59) 2.54 3.24
MSP18 Obs 3 0.88 $\rm0._{0.}^{0.11}$ $\rm 3.04_{2.65}^{3.43}$ $\rm0.32_{0.31}^{0.36}$ 1.00 (56) 2.88 3.78
MSP167 Obs 1 0.98 $\rm0.35_{0.}^{0.88}$ $\rm 1.58_{1.07}^{2.27}$ $\rm0.11_{0.08}^{0.19}$ 1.02 (12) 0.52 0.77
MSP167 Obs 2 0.98 $\rm0._{0.}^{0.22}$ $\rm 2.32_{1.91}^{2.72}$ $\rm0.10_{0.09}^{0.12}$ 1.95 (21) 0.72 1.10
MSP167 Obs 3 0.98 $\rm0.68_{0.}^{1.15}$ $\rm 1.28_{0.91}^{2.32}$ $\rm0.16_{0.09}^{0.28}$ 0.95 (11) 0.56 0.78
MSP188 Obs 1 0.96 $\rm0.45_{0.23}^{0.69}$ $\rm 1.22_{1.00}^{1.40}$ $\rm0.24_{0.20}^{0.33}$ 1.56 (26) 0.88 1.51
MSP188 Obs 2 0.96 $\rm0.36_{0.}^{0.52}$ $\rm 1.33_{1.20}^{1.86}$ $\rm0.22_{0.16}^{0.26}$ 0.73 (33) 0.88 1.49
MSP188 Obs 3 0.96 $\rm0.70_{0.56}^{0.84}$ $\rm0.97_{0.84}^{1.09}$ $\rm0.30_{0.25}^{0.38}$ 1.52 (30) 0.74 1.33
HD 90273 Mgd 0.22 $\rm0.01_{0.}^{0.38}$ $\rm0.41_{0.22}^{0.52}$ $\rm0.02_{0.}^{0.17}$ 0.88 (33) 0.16 0.28
MSP157 Mgd 0.92 $\rm0._{0.}^{0.51}$ $\rm 1.53_{1.08}^{1.92}$ $\rm0.010_{0.}^{0.018}$ 0.97 (8) 0.057 0.12
MSP165 Mgd 1.08 $\rm 1.77_{1.29}^{2.48}$ $\rm0.28_{0.20}^{0.38}$ $\rm 1.66_{0.}^{13.2}$ 0.59 (10) 0.088 0.20
MSP175 Mgd 0.91 $\rm 1.31_{1.18}^{1.88}$ $\rm0.21_{0.14}^{0.28}$ $\rm 2.25_{0.}^{59.8}$ 1.20 (15) 0.057 0.18
MSP183 Mgd 1.03 $\rm0.56_{0.36}^{0.85}$ $\rm0.63_{0.45}^{0.82}$ $\rm0.10_{0.}^{0.25}$ 0.94 (20) 0.14 0.45
MSP203 Mgd 0.95 $\rm0.19_{0.}^{0.47}$ $\rm0.99_{0.74}^{1.14}$ $\rm0.03_{0.02}^{0.05}$ 1.09 (21) 0.11 0.32
MSP263 Mgd 1.09 $\rm 1.09_{0.62}^{1.65}$ $\rm0.31_{0.18}^{0.53}$ $\rm0.25_{0.}^{5.98}$ 0.89 (7) 0.034 0.12
Src 2 Mgd 1.08 $\rm 1.42_{0.71}^{1.71}$ $\rm0.39_{0.33}^{0.68}$ $\rm0.40_{0.}^{0.77}$ 1.20 (16) 0.088 0.19


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