GALAXIES: Inside the Universe's Star Cities

In the 1950s, radio observations revealed the presence of often millions of solar masses of interstellar gas, showing that some galaxies emitted much of their power at radio wavelengths, a process requiring massive injections of electrons moving at nearly the speed of light. These data and x-ray observations led to the recognition that multimillion solar mass blackholes lurk in the centres of most giant galaxies. With the confirmation of the Big Bang model, it was obvious that galaxies had to form in the early universe and then evolve into their present-day structures. However, theoretical model for galaxies consisting of only normal baryonic matter failed to produce credible results and the answer came from an unexpected quarter. An extra invisible component, the dark matter halos, evidently surround galaxies and make up most of their mass. In the late 20th century, the Hubble Space Telescope and ground-based 8-10m aperture telescopes opened the way to the study of useful galaxies. So where are we now? This book introduces the world of galaxies from a 21st century perspective with the help of fully realised why what we are seeing is one of nature's wonders. Very clear explanations, good graphics and wonderful galaxy pictures in colour, nice layout and typography. 22.3 x 25.9cm, small remainder mark. 256pp.