| 1. |
- Chu, H.S., et al.
(författare)
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Discovery of Helical Magnetic Fields in AGN and CME and Ejection of Large Scale Magnetic Fields from AGN
- 2003
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Ingår i: Symposium - International astronomical union. - : International Astronomical Union. - 0074-1809. ; 214, s. 303-310
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic Fields are the crucial and most important ingredient involved in the processes of various violent activities in Active Galactic Nuclei and other celestial bodies. The generally accepted 2-sided symmetric-jets model of active galactic nuclei (AGN) does not include the magnetic fields. We present here the first direct detection of helical magnetic field in AGN, and the first direct detection of ejection of large scale magnetic fields from AGN. (CME) 2. The annular (helical) magnetic field is responsible for the collimation of the jet (through Pinch Effect) and may be of crucial importance for extraction of black hole rotational energy. 3. The CMEs are responsible for sporadic ejection of jet components in AGN, while the general accepted 2-sided jets pertain to the quiescent Jets. 4.Observations show that the CME with Asymmetric Jets can explain many phenomena and much of the morphological diversities in AGN.
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| 2. |
- Rantakyrö, F.T., et al.
(författare)
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Multifrequency interferometer and radio continuum monitoring observations of CTA 102
- 2003
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Ingår i: Astronomy and Astrophysics. - Berlin : Springer. - 0004-6361 .- 1432-0746. ; 42:5, s. 473-485
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Tidskriftsartikel (refereegranskat)abstract
- This paper represents the work of several years of observation of CTA 102 with both single dish telescopes andinterferometric arrays, covering wavelengths from 1.2 cm to 1.3 mm. The resolution of the maps covers an order of magnitudefrom 0.5 mas to 50 μas. The images presented demonstrate the rapid structural changes in this source. These rapid structuralchanges correlates with the outbursts seen in the total flux, turnover frequency and in the spectral index. We have calculated theBrightness Temperatures of the components (TB ) directly from the determined component sizes and also using the logarithmicvariability amplitudes and timescales to calculate the TB s. Both the methods yielded measurements of source frame T Bs nohigher than∼a few × 1012K. We find that the observed average proper motion is0.4 0.07 mas/yr, which corresponds to anapparent transverse velocity of 11± 2 c.
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| 3. |
- Witter, E, et al.
(författare)
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A study of the structure and metal tolerance of the soil microbial community six years after cessation of sewage sludge applications
- 2000
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Ingår i: Environmental Toxicology and Chemistry. - 0730-7268. ; 19:8, s. 1983-1991
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Tidskriftsartikel (refereegranskat)abstract
- Changes in soil microbial community structure and development of metal tolerance as a result of past applications of unamended sewage sludge and metal-amended sewage sludge were found in soils of a long-term field experiment at Braunschweig, Germany. Both the rate of sewage sludge application and metal amendment affected the size and activity of the microbial biomass and had caused changes in microbial community structure as seen by differences in phospholipid fatty acid (PLFA) profiles. Past sewage sludge additions and metal amendment had an effect on the microbial respiratory response to 15 different C substrates, but both the magnitude and the direction of this response were substrate dependent. Differences between the soils in the respiratory response to the substrates were therefore probably largely determined by differences in the composition of the microbial consortia utilizing the substrates. The level of metal tolerance of the soil bacterial community determined by the thymidine incorporation technique and that of the microbial consortium growing on glucose in situ (determined from respiration measurements) increased with the level of metal contamination of the soil. Metal tolerance measurements could identify the metal with the largest toxicity effect in this experiment with multiple metal-polluted sewage sludge.
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