Seyfert galaxies

The observation that both quasars and Seyfert galaxies appear to be exploding objects that release massive amounts of matter, ostensibly from nowhere [105] - p.343, in a mini-creation event, provides this mechanism. To complete the cycle it is only necessary to identify the black-hole singularity with the origin of the quasar emission. It becomes a viable possibility if the black hole and the quasar are on opposite sides of an interface between two regions of space-time. 

Emission lines are observed in the light from so-called active galaxies, also known as Seyfert galaxies. Emission spectra are also emitted by quasars or quasi-stellar objects (QSO). Like the absorption lines of normal galaxies these emission lines are also redshifted. 

The final word on nucleogenesis has obviously not been spoken. There are just too many loose ends and imwarranted assumptions to provide a consistent picture. Too many alternative mechanisms are ignored without mention or comment. The role of black holes, quasars, Seyfert galaxies and white holes, all of which could participate in a chain of nuclear synthesis, is not understood and therefore ignored. Even cosmic ray abundances, matched on the scale of solar abundances show up some important discrepancies. Both H and He have low abundances in cosmic rays, whereas the elements Li, Be and B are 5 orders of magnitude more abimdant. The relatively low... 

Many sources with prominent emission spectra, such as Seyfert galaxies and quasars, which could be of this type, have been observed. According to this interpretation cosmic matter is neither dispersed nor created in time, but recycled. The constant two-way flow across the interface has reached a steady state which gives the universe the appearance of being static. 

Figure 3 Simulation of an observation by SAX-NFI of a Seyfert 1 galaxy (MCG-6-30-16) with several of the features observed in the last 10 years by Afferent satellites a soft excess below 1 keV (EXOSAT), an edge of ionized oxygen at 0.8 keV (ROSAT, ASCA), a broad iron Hne (FWHM = 0.7 keV) at 6.4 keV and a high energy bump between 10 and 200 keV (GINGA). The spectrum is fitted with a simple power law and the residuals clearly show all those components. In the blow-up in the bottom of the figure the residuals of the MEGS around the broad iron line are plotted, showing that the line is well resolved by the detector.

NGC 1068 is the prototype for Class II Seyfert galaxies, in which the forbidden lines and the Balmer lines have the same widths... 

Upper limits have been obtained on 7 other extragalactic sources. Observations by Telesco al. (1976b) place 2a upper limits of - 50 Jy at lOOp on the class I Seyfert prototype NGC 4151, NGC 4705, M 51, M 33, the archetype of normal galaxies M 31, and the most luminous galaxy MKN 231. A similar limit was obtained for MKN 231 by Harvey and Hoffman (1976). Telesco et al. (1976b) have also obtained a 2a upper limit of 4 Jy at lOOy on 3C 273. 

Fig. 7.16 An artist conception of water maser emission in the accretion disk of the accretion disk and radio jet around the black hole in the heart of the Seyfert galaxy NGC 4258. This accretion disk material lies within a few tenths of a parsec from a supermassive black hole. The disk is warped, rotating differentially according to Kepler s laws. The inset at the bottom of the graphic is a radio spectrum (intensity as a function of frequency or velocity) of the water maser emission. The white glints on the disk surface show the locations of regions where maser emission has been detected. Image courtesy of NRAO/AUl and Artist John Kagaya (Hoshi No Techou)...

Initial Results of a Survey of Seyfert 1 Galaxies and Quasars With the UCLA 2.1-micron Array Camera... 

Three galaxies, Mrk 231, IRAS 05189-2524, and IRAS 07598-1-6508, possess optically active nudei (Seyfert or LINER types) and show evidence in the near-infrared of a circumnudear starburst. On physical scales of 4kpc these galaxies have very red near-infrared colors, with H-K >0.8. These... 

In contrast, the Seyfert 1 galaxy Mk 1239 appears unresolved at 10.3. The measured fiux density of 0.63 Jy is in excellent agreement with the IRAS value and a canonical spectral shape, indicating a dominance of the active nucleus and no contribution from an extranuclear source. Properties of the complete sample will be discussed in a separate publication. 

The most distingtdshing diaracteristic of quasi-stellar objects (QSOs) and type 1 Seyferts, compared to the rest of active galaxies, is the presence of broad emission lines. These lines represent a key element in the study of these objects, both because of their similarity when comparing objects with a wide range of luminosities, and because they can be completely absent in some objects with otherwise strikingly similar characteristics to those with broad lines. 

Line emission from [FdQ] is produced by dectron collisions from fast shocks and possibly hard photoionization (PJ.). As wdl as the correct ionization conditions, we seem to require an enhanced abundance of Iron in the gas phase (Greenhouse ei aX. 1991). Such a grain destruction medianism would result from a SN blast wave, or other fast shocks. The non-thermal radio emission from starburst galaxies is due to SNRs and superwinds, fri Seyfert galaxies this emission is often associated with jets or lobes powered by processes at very small scales (possibly a black hole). It can be difficult to separate these different mechanisms by radio emission or spectral index alone. 

Fig. 1 shows the [Fell] vs 6cm radio emission from the nuclear region of active galaxies, using data from the literature and our own work (Forbes Ward 1993). For starburst galaxies this correlation is simply q>lained in terms of SN activity. The [FeD] emission can therefore provide an independent estimate of the SN rate. For Seyfert galaxies th re may be an additional component due to radio jet induced shocks. High resolution line imaging will provide an important test. 

Fig. 1. Nndear legion [Felll 1.64 m line vs 6cm radio emission fox active galaxies. A verjr strong correlation (a = 0.27) is seen over several orders of magnitnde. Filled circles, triangles and squares represent starbu or LINER galaxies, galaxies with composite spectrum and Seyfert galaxies req>ectively.

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