Old or Young Giant Bulge-Dominated Low-Surface Brightness Galaxies

Low surface brightness galaxies (LSBs) might appear optically unimpressive, butthe largest LSBs contain as many stars as the largest normal elliptical andspiral galaxies. Very little is known about their Xray properties. We proposeshort XMMNewton observations of three giant, bulgedominated LSBs that coverover a factor of four in Kband luminosity to create the first Xray LSB sample,and compare their L_X/L_K scaling relation with normal earlytype spiralbulges/ellipticals. We will also search for AGN in the nuclei and ULXs in thefaint disks of these intriguing systems. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]