Thursday, February 14, 2019
Quasars Essay -- Essays Papers
QuasarsSince their discovery, the nature of quasars has been adept and only(a) of the most intriguing and pose problems as evidenced by the following quotations the problem of sagaciousness quasi-stellar objects is one of the most important and fascinating tasks in all physics - G.Burbidge and Hoyle. The quasar continues to rank both as one of the most baffling objects in the universe and one most capable of inspiring heated parametric quantity - Morrison. The redshift problem is one of the most critical problems in astronomy nowadays - G. Burbidge. Quasars still remain the profoundest mystery in the heavens - Hazard and Mitton. The formulaic interpretation of the spectral lines observed in quasars is based on the redshift shot. trine hypotheses oblige been advanced to account for the supposed redshifts 1. Cosmological hypothesis the redshifts are due to the expansion of the universe, 2. Gravitational hypothesis, 3 Local-Doppler hypothesis in this hypothesis the redshifts are due to the Doppler effect, but the quasars are relatively nearby and take for nothing to do with the expansion of the universe. Of these hypotheses, the first one is the most publicise one. One is led to attribute to quasars very many an(prenominal) mysterious properties if one assumes the redshift hypothesis to be correct. A patient analysis of the data on quasars over the years has led to the conclusion that the real source of the interrupt is in the assumption that the spectra of quasars have redshifts.In the early 1960s quasars were realizen as intercommunicate stars because the method used to discover the first quasars was based on coincidences amid a cockeyed radio source and a point-like optical source. Since all(prenominal) radio source was associated with a star it was originally thought that quasars were objects indoors the galaxy hence the term radio stars. Quasars or quasi-stellar radio source, from the method by which they where originally di scovered as stellar optical counterparts to small regions of healthful radio emission. With increasing spatial resolution of radio telescopes the strong radio emission often seemed to come from a pair of lobes surrounding many of these faint star-like emission line objects.The initial method of selection was strong radio emission, and then later any object with blue or ultraviolet excess wa... ... between galaxies, either through direct collisions or near encounters, can be important in turning on a quasar, by dumping fuel onto a black hole. in time some quasars look unperturbed, so there may be other, more(prenominal) subtle mechanisms for feeding the black hole. Some of the galaxies we observed dont appear to know they have a quasar in their core.3. Quasars that are radio quiet down are often in elliptical galaxies, not always in spiral galaxies, as previously believed. Advanced instruments planned for Hubble should also do pin down more details. The Near Infrared Camera and Multi-Object mass spectrometer (NICMOS), to be installed in 1997, and the Advanced Camera, to be installed in 1999, will have coronagraphic devices which will block out the glare of a quasar, allowing astronomers to see juxtaposed into a galaxys nucleus. By viewing galactic structures in infrared shed light on , the NICMOS should be able to provide important new details about the host galaxies of quasars. The continued study of quasars and the information that it will provide us with may help us to develop a better understanding of space and how we fit in to this great puzzle.
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