's Cerro Tololo Inter-American Observatory (CTIO) , obtained using two special filters that reveal the glow of oxygen and hydrogen , with X-ray data from Chandra and XMM-Newton , which are overlaid in blue. Photo credit: X-ray: NASA/CXC/Univ.Potsdam/L. Oskinova et al & ESA/XMM-Newton; Optical: AURA/NOAO/CTIO/Univ.Potsdam/L. Oskinova et al Note: For more