SIMBAD references

We study the properties of hot gaseous halos in 10 nearby ultraluminous IRAS galaxies observed with the ACIS instrument on board Chandra. For all sample galaxies, diffuse soft X-ray emissions are found within ∼10 kpc of the central region; their spectra are well fitted by a MEKAL model plus emission lines from α-elements and other ions. The temperature of the hot gas is about 0.7 keV and metallicity is about 1 Z_☉. Outside the central region, extended hot gaseous halos are found for 9 out of the 10 ultraluminous infrared galaxies (ULIRGs). Most spectra of these extended halos can be fitted with a MEKAL model with a temperature of about 0.6 keV and a low metallicity (Z∼0.1 Z_☉). We discuss the implications of our results on the origin of X-ray halos in elliptical galaxies and the feedback processes associated with starbursts.