Quasar

The search for radio galaxies led to the unexpected discovery of what became known as quasi-stellar objects, QSO s, or quasars. The first quasars to be discovered were all strong radio sources, but the majority known today are radio silent. More characteristically, most of them are X-ray sources. However, the most characteristic property of quasars is the unusually large redshifts of their optical emission spectra. Analyses of the physical properties of quasars and speculation about their nature are tainted by the conviction that these redshifts are fully accounted for by Hubble s law. 

Apart from redshift, the two most conspicuous properties of quasars are their small angular diameters and high optical luminosity. Should the Hubble distance be real the absolute optical Imuinosity of a quasar, although a thousand times smaller in diameter, exceeds the output of even the brightest galaxy by orders of magnitude. 

To complicate the picture, several quasars are observed to be variable in both radio and optical emission. The period of variation limits the physical size of the object to values far below the size implied by the angular diameter 

We shall return to further anomalies associated with quasars and their spectra. At this stage it is worth noting that Hubble s law applied to quasars, whatever they are, is an unsolved problem of astrophysics. 

Bergmann, P.G. (1976) Introduction to the theory of relativity, Dover edition, NY. 

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J. D. Kraus, Radio Astronomy, 2nd ed., Cygnus-Quasar Books, PoweU, Ohio, 1986. 

Visit gopher //quasar.tach.net 3020/71/msds. This is the Vermont state SIRI Web. You will find a searchable (manufacturer or product name) gopher index of MSDSs. 

Anderson, G.M. Braun, G. Braun, U. Nichols, D.E. and Shulgin, A.T. Absolute configuration and psychotomimetic activity. In Barnett, G. Trsic, M. and Willette, R., eds. Quasar Quantitative Structure Activity Relationships of Analgesics, Narcotic Antagonists, and Hallucinogens. National Institute on Drug Abuse Research Monograph 22. Rockville, MD the Institute, 1978. pp. 8-15. 

QUASAR QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIPS OF ANALGESICS, NARCOTIC ANTAGONISTS, AND HALLUCINOGENS. Gene Barnett, Ph.D. Milan Trsic, Ph.D. and Robert Willette, Ph.D. eds. 

Moreover, the extragalactic object 3cl23 was observed to look for the H,C236o. in absorption, and the upper level (3a) for Ti/Tc absorption of 1.5% is achieved. So far, that is rougher than Dr. Matveenko has observed (private communication, 27.04.04, at conference in Pushchino, Russia) the H78a absorption line toward 3c345 quasar (RT100, Bonn) with, probably, amplitude of 0.5%... 

The epoch and mode of galaxy formation are not well known, but both quasars and star-forming galaxies are known with redshifts up to about 7, corresponding to an era when the expanding Universe was only 1/8 of its present size, and the emission-line spectra of quasars indicate a large heavy-element abundance (solar or more Hamann Ferland 1999), suggesting prior stellar activity. The first stars, on the other hand, known as Population IIP, would have been devoid of metals whether they differed from normal stars in other basic characteristics, notably their mass distribution, is not known, since no completely metal-free stars have been... 

The term QSOs is used to cover both radio-loud quasi-stellar objects, commonly known as quasars , and radio-quiet objects that otherwise have similar characteristics. 

Observations of distant objects, notably high-redshift star-forming ( Lyman-break ) galaxies and absorption line systems on the line of sight to quasars, give some information on chemical evolution at epochs not too far from when the first stars and most galaxies were presumably formed. Other information comes from two related effects ... 

The IRAS galaxies provided some of the earliest evidence from redshift surveys, and from source counts as a function of observed flux, that the spiral galaxy population has undergone evolution (ORS see Fig. 12.2). This result is analogous to similar evidence from source counts of radio galaxies and quasars, as well as quasar redshifts, and a correlation that has been observed between radio and infrared luminosity suggests that the evolution could be similar in both cases. Typical simple models for such evolution include luminosity evolution according to... 

Fig. 12.7. Zn abundances in DLAs on lines of sight towards optically (faint symbols) and radio-selected (bold symbols) quasars open triangles denote upper limits. The optically selected objects come from a compilation by Kulkarni et al. (2005). After Akerman et al. (2005).

Discovery of first gravitational lens (the double quasar 0957+561). 

The Heisenberg/Bohr model allows us to simulate the physical universe of stars, galaxies, and quasars but it doesn t explain organisms or mind. We have to overlay that atomic model with different qualities in order to represent more complex phenomena. We must imagine an atom with new parameters if we wish to understand how we could exist, how thinking, tool-using, human beings could arise out of the universal substratum. 

A diffuse X-ray background is perceived between these brilliant sources. It comes for the greater part from remote regions outside our Galaxy, probably quasars and other active galaxies. Added to these more distant emissions is a galactic component emitted by the hotter interstellar gases. 

The VLT, centrepiece of the ESO, promises an exceptional harvest of astronomical data. Understanding the chemical evolution of the Universe requires a coordinated study of the most remote objects, ancient stars in the galactic halo and absorbent clouds in the line of sight of quasars. To this end, the high-resolution spectrograph UVES (Ultraviolet Echelle Spectrograph) was set at one focus of Kueyen, one of the four components of the VLT, perched at the top... 

FUSE (Far Ultraviolet Space Explorer) combs the sky in search of the spectra of hot bright background objects (quasars and stars) modified by absorption lines due to interposed clouds (both extragalactic and interstellar). Its main prey is deuterium, an atom of major cosmological significance. It shonld also establish a detailed breakdown of interstellar gases. FUSE is a NASA project with French participation. ... 

Along the line of sight towards a quasar he huge quantities of absorbing material, with varied composition and structure. Measured abundances concern only the gaseous component of this material. For this reason, abundances are distorted by dust, which subtracts atoms in varying amounts depending on their affinity for the sohd state. 

FIGURE 2. Calculated powder patterns for spin-1 (a) and spin-3/2 (b) nuclei with a dominating quadrupolar interaction (QUASAR simulation) tj is the asymmetry parameter of the quadmpolar interaction (equation (9))... 

J. P. Amoureux and C. Fernandez, QUASAR—Solid-State NMR Simulation for Quadrupolar Nuclei, LiUe, 1996. 

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