The Quasar 3C345
Quasars: The most tremendous Energy Monster of the UniverseA Quasar is the Active-Galactic-Nuclei (AGN) of a special galaxy. This galaxy nucleus has about the size of our solar system. This means that the dimension of such an AGN is about 300 micros of its host galaxy. The particularity of a Quasar is that this relatively tiny area emits 100-1000 more light than all stars together in the host galaxy. With other words: Up to 1000 times more light (compared with all stars of the host galaxy) is generated in an area which is only about 300 micros of the host galaxy size. To generate such an amount of energy in such a relatively tiny area one needs a very special mechanism. Astronomers believe to 99.9% that the central engine of a Quasar is a super-massive Black Hole which swallows up continuously matter (e.g stars). This matter is accelerated and heated up so much that this relatively tiny nucleus can radiate as 1 trillion suns together. A star like our sun, which exists about 10 Billion years, is "eaten up" by such a super-massive black hole in less than one year. The matter is absorbed in a vortex (whirlpool) which is called accretion disc and the mass of the super-massive black hole grows continously. It can reach a mass which has a weight like a few billion suns together. With other words: One has to compress about 1 quadrillion Earth like planets in an area which has only the small dimension of our solar system. Huge vast Plasma-Beams generated by super-massive Black HolesA part of the matter which is attracted by the super-massive black hole does not fall into the black hole but is deflected by strong magnetic fields into huge vast plasma-beams (called jets). These jets which consist of electrons, positrons and protons, are shot out of the nucleus with almost the speed of light and emit a special kind of radiation (synchrotron radiation). This radiation can be observed by radio-telescopes. The picture shown here of the quasar 3C345 shows such a plasma-jet which is emitted nearby a super-massive black hole. In the lower left corner of the picture below one sees the observable origin of the jet (the red ellipse). With distance to the super-massive black hole the jet becomes diffuse (visible as the blue and purple jet color). It is remarkable that the jet is not straight but curved. 
A Telescope with Earth sizeSince quasars are far away from Earth (the light needs some billion years to reach us) and the tiny dimension of the nucleus where the jet is emitted, one would need a radio-telescope which has the size of the Earth to observe these jets. Obviously one can not build such a huge telescope but astronomers developed a powerful technique to synthesize such a huge telescope. One simultaneously observe the astronomical object with many radio-telescopes around the world. The received signals are stored on tapes (amount of Terra-bytes) and are put together later on (correlated) with a super-computer. The picture is generated afterwards by the astronomer using special mathematical algorithm on a workstation. The received picture has the resolution like one has observed the astronomical object with one telescope which has the size of the Earth. This technique is called Very-Long-Baseline-Interferometry (VLBI). 38 Radio-Telescopes all over the world were used simultaneously to made the image of the Quasar 3C345 shown above. The participating telescopes were the Very-Large-Array with 27 telescopes in New Mexico, USA, the Very-Long-Baseline-Interferometer with 10 telescopes spread over the whole USA and the 100m radio-telescope in Effelsberg nearby Bonn, Germany.   
A Telescope 4 times bigger than EarthIf one wants to look deeper into the jet as with the technique mentioned above one needs a telescope which is bigger than the Earth. The only possibility to do this is to place a radio-antenna in space. Japanese astronomers built such a space radio-telescope and placed it successful in an orbit. 
To obtain the left image in the picture below, this space-telescope HALCA was used additionally to the 38 ground-telescopes on Earth and increased the image resolution 3-4 times. One sees immediately the gain of resolution. One can look into the observable jet origin (seen in the right image as the red ellipse) and several so-called plasma-components (the orange and turquoise ellipses) are revealed in the left image.
The particular Quasar 3C345 (are there 2 Black Holes?)We have observed the quasar 3C345 several times within a couple of years which enabled to trace and to study the evolution of these plasma components (e.g.: they move from left to right and change their strength). With these observations we can learned a lot about these most tremendous energy monster of the universe. One particularity of the Quasar with the catalogue number 3C345 is that the jet points almost towards us. This is responsible to a curious effect. The plasma components move with an apparent speed of 3-20 times of the speed of light (called: superluminal motion). But attention: This is just an illusion (a projection effect) and the true speed of the components in the jet is "just" about 99.9% of the speed of light. Another peculiarity is that these plasma components travel on curved trajectories, like the helical geometry of the DNS (the components of life). Furthermore, these trajectories differ from one component to the other and several aspects of this jet seems to repeat after 8 to 10 years. This rise up many questions and we want to know what is the mechanism behind these observed peculiarities. Might it be that this quasar contains 2 super-massive Black Holes which revolve each other? I will give possible answers here soon. A MOVIE of the Plasma-Jet in the Quasar 3C345Since we have a big number of observations of this quasar we are able to make a movie out of it. With at least 3 (better more) observations per year on can interpolate between these pictures and produce a movie. This gives the opportunity to observe the ejected plasma components in their evolution. The brightness of single jet-components is proportional to the flux density which gives additional physical information beside the kinematical ones. The colors are selected in a way to get a better "feeling" of the ejected plasma. If you click on the following picture, an animated gif (1.2MB) will be loaded and started. 
Coming soonPublications:This image of the quasar 3C345 made by me was published in: 
Upper Left: Article in Science, Volume 287, 18 February 2000, Page 1195 Upper Middle: Highlight Poster of the VSOP Mission (Space mission with Very-Long-Baseline-Interferometry) Upper Right: Japanese Calendar 2001 of the Institute of Space and Astronautical Science, Sagamihara, Japan Lower Left: Advertising Poster of Space Very-Long-Baseline-Interferometry Lower Right: Proceedings Book: Astrophysical Phenomena revealed by Space Very-Longe-Baseline-Interferometry You can read my scientific publications about this quasar here: A sharper view into the parsec-scale jet of 3C345 (pdf, 444Kb) The quasar 3C345 at highest resolution with mm- and space-VLBI (pdf, 296Kb) Quasi-Periodic Changes in the Parsec-Scale Jet of 3C345 (pdf, 75Kb) There is a link to my Ph.D. thesis at the server of the Universität- und LandesBibliothek Bonn: Quasi-Periodicity of the Parsec-Scale Jet in the Quasar 3C345 - A High Resolution Study using VSOP and VLBA - pdf: The publications and the Ph.D. thesis are readable and printable with the free 
of Adobe.
|