The supergiant shell LMC 2. II. Physical properties of the 10(6) K gas

LMC 2 has the highest X-ray surface brightness of all known supergiant shel ls in the Large Magellanic Cloud (LMC). The X-ray emission peaks within the ionized filaments that define the shell boundary but also extends beyond t he southern border of LMC 2 as an X-ray bright spur. ROSAT HRI images revea l the X-ray emission from LMC 2 and the spur to be truly diffuse, indicatin g a hot plasma origin. We have obtained ROSAT PSPC and ASCA SIS spectra to study the physical conditions of the hot (greater than or equal to 10(6) K) gas interior to LMC 2 and the spur. Raymond-Smith thermal plasma model fit s to the X-ray spectra, constrained by H I 21 cm emission line measurements of the column density, show the plasma temperature of the hot gas interior of LMC 2 to be kT similar to 0.1-0.7 keV and of the spur to be kT similar to 0.1- 0.5 keV. We have compared the physical conditions of the hot gas in terior to LMC 2 with those of other supergiant shells, superbubbles, and su pernova remnants (SNRs) in the LMC. We find that our derived electron densi ty for the hot gas inside LMC 2 is higher than the value determined for the supergiant shell LMC 4, comparable to the value determined for the superbu bble N11, and lower than the values determined for the superbubble N44 and a number of SNRs.