SIMBAD references

We report on observations of the superbubbles (SBs) N11 and N51D in the Large Magellanic Cloud (LMC) with Suzaku and XMM-Newton. The interior of both SBs exhibits diffuse X-ray emission, which is well represented by thin thermal plasma models with a temperature of 0.2-0.3 keV. The presence of nonthermal emission, claimed in previous works, is much less evident in our careful investigation. The 3σ upper limits of 2-10 keV flux are 3.6x10^–14 erg/cm2/s and 4.7x10^–14 erg/cm2/s for N11 and N51D, respectively. The previous claims of the detection of nonthermal emission are probably due to the inaccurate estimation of the non-X-ray background. We conclude that no credible nonthermal emission has been detected from the SBs in the LMC, with the exception of 30 Dor C.