Picture of the month
An enormous jet of matter expulsed from quasar PKS 1127-145 has been observed in the X-ray region by the Chandra satellite (right). This quasar is about 10 000 million light-years distant from the Earth (z = 1.187) and its jet extends over a distance of at least 1 million light-years, or about 10 times the diameter of our galaxy. The strong X-ray emission of the jet arises from interactions between relativistic electrons in the jet and photons of the cosmological microwave background. The image on the left, obtained using the Hubble Space Telescope in the visible region, shows the same field of view (40 x 32 arcsec). Distant galaxies appear, but the quasar is invisible. (X-ray: NASA/CXC/A Siemiginowska (CfA) and J Bechtold (U Arizona). Optical: NASA/HST/CfA/A Siemiginowska et al.)