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81.
Marc Elmouttie Bärbel Koribalski Scott Gordon Keith Taylor Sally Houghton Tracy Lavezzi Raymond Haynes & Keith Jones 《Monthly notices of the Royal Astronomical Society》1998,297(1):49-68
The TAURUS-2 Fabry–Perot interferometer, mounted on the 3.9-m Anglo-Australian Telescope, has been used to observe the Circinus galaxy. We have mapped the intensity and velocity distribution of the ionized hydrogen in the galaxy using the Balmer series Hα spectral line.
The semiresolved core (observed with a seeing disc of 30 pc) appears amorphous in shape, which is commonly observed in Seyfert 2 galaxies. Its peak coincides with the core position measured in the radio continuum, suggesting that ionized gas surrounds a non-thermal source.
A circumnuclear ring or spiral of radius 220 pc and a rotational velocity of 350 km s−1 (assuming circular motions) surrounds the core. The inclination angle of this feature, i =40°±10°, is less than that of the previously observed radio continuum disc. The velocity channel maps obtained for the Hα ring show that the kinematics resemble those of a rotating ring and the intensity displays a complex structure indicative of several, unresolved, H II regions. We believe the ring to represent a circumnuclear starburst.
Our Hα data also show the presence of the previously detected [O III ] ionization cone to the north-west of the core, measuring more than 400 pc in length. We suggest that the ionization cone lies in a different plane from that of the starburst ring and is directed away from us. Several kinematic components of the core are derived and we calculate an outflow velocity in excess of 150–200 km s−1 for gas above the core of Circinus. We also present evidence for inflowing ionized gas at the centre of Circinus.
The correlation of the Hα and radio continuum features is discussed, as well as the possible presence of a starburst-driven superwind in the Circinus galaxy. 相似文献
The semiresolved core (observed with a seeing disc of 30 pc) appears amorphous in shape, which is commonly observed in Seyfert 2 galaxies. Its peak coincides with the core position measured in the radio continuum, suggesting that ionized gas surrounds a non-thermal source.
A circumnuclear ring or spiral of radius 220 pc and a rotational velocity of 350 km s
Our Hα data also show the presence of the previously detected [O III ] ionization cone to the north-west of the core, measuring more than 400 pc in length. We suggest that the ionization cone lies in a different plane from that of the starburst ring and is directed away from us. Several kinematic components of the core are derived and we calculate an outflow velocity in excess of 150–200 km s
The correlation of the Hα and radio continuum features is discussed, as well as the possible presence of a starburst-driven superwind in the Circinus galaxy. 相似文献
82.
Dr. Richard F. Wright Prof. Albert Matter Marc Schweingruber Ulrich Siegenthaler 《Aquatic Sciences - Research Across Boundaries》1980,42(2):101-126
A 2-year study of sedimentation in Lake Biel reveals that three major factors can account for the spatial and temporal patterns
of tripton sedimentation. Allochthonous inputs of particulate matter mostly derived from the Aare river during spring snowmelt
and other high-water periods, provide about 50% of the carbonate and 50% of the siliceous matter collected in sediment traps.
Phytoplankton activity in this eutrophic, hard-water lake accounts for the rest of the carbonate and siliceous matter, the
latter being mostly diatom frustules. Sedimentation rates are thus highest during periods of maximum river flooding, maximum
phytoplankton activity and following the breakdown of the thermocline, at which time trapped particles settle out. Resuspension
of sediment is important in at least one basin. Resolution of carbonate appears to be minor. 相似文献
83.
Marc Schoeller 《Journal of Hydrology》1976,28(1):45-52
The relationship line between two chemical constituents dissolved in groundwater does not always begin at the graph origin, but at a fixed coordinates point. This allows the separation between rain water, infiltrating water and groundwater. Besides, this relationship line is not always linear. Equations are given for the curvilinear case. 相似文献
84.
85.
G. Steinmann 《International Journal of Earth Sciences》1929,20(2):136-145
Ohne Zusammenfassung 相似文献
86.
87.
88.
Steinmann 《International Journal of Earth Sciences》1916,6(7-8):427-428
Ohne Zusammenfassung 相似文献
89.
Salomon Wilheim Salomon Cloos Steinmann Otto Wilckens Donath E. Spengler Jurasky Wilckens 《International Journal of Earth Sciences》1928,19(2):146-153
Ohne Zusammenfassung 相似文献
90.