BRIGHTEST CLUSTER GALAXIES (BCGS) RESIDING IN THE HEARTS OF GALAXY CLUSTERS ARE LUMINOUS AND MASSIVE ELLIPTICALS WITH LITTLE STAR FORMATION. A RECENT STUDY HINTED THAT MASSIVE EXTENDED BLUE STAR-FORMING GALAXIES (SUPER SPIRALS) MAY BE THE BCGS OF SEVERAL GALAXY CLUSTERS. CLEARLY SUCH A BCG POPULATION WOULD BE AT ODDS WITH OUR UNDERSTANDING ABOUT THE FORMATION OF THESE GALAXIES. HOWEVER BASED ON THE PRESENTLY AVAILABLE DATA IT COULD NOT BE UNEQUIVOCALLY DEMONSTRATED THAT SUPER SPIRALS ARE TRULY BCGS. THEREFORE WE REQUEST EXPLORATORY XMM-NEWTON OBSERVATIONS TO MAP THE MORPHOLOGY OF THE INTRACLUSTER MEDIUM MEASURE THE OFFSETS BETWEEN THE PEAK OF THE DIFFUSE X-RAY EMISSION AND THE POSITION OF THE CANDIDATE BCGS AND HENCE DIRECTLY PROBE IF SUPER SPIRALS ARE TRUE BCGS.

Smithsonian Institution, Washington DC

Investigators