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1.
5个新发现的X选BL Lac天体 总被引:1,自引:0,他引:1
利用ROSATVLA方法筛选,从ROSATX射线源中选出了一批新的BLLac天体和类星体的候选体.1996年12月8日至17日,利用北京天文台2.16m望远镜和新从美国引进的OMR摄谱仪,对这批新候选体进行了光谱认证.经SUN工作站处理,又发现了5个新的X选BLLac天体.此外,还对去年作者在OMR引进之前发现的BLLac天体进行了检验,结果发现,去年发现的7个BLLac天体中,2322+343的CaIIH&K“Breakstrength”为26.9%,稍大于判据25%,因此,2322+343到底是BLLac天体还是射电星系还有待于进一步测光及偏振观测的验证. 相似文献
2.
Guinevere Kauffmann Timothy M. Heckman Simon D. M. White Stéphane Charlot Christy Tremonti Jarle Brinchmann Gustavo Bruzual Eric W. Peng Mark Seibert Mariangela Bernardi Michael Blanton Jon Brinkmann Francisco Castander Istvan Csábai Masataka Fukugita Zeljko Ivezic Jeffrey A. Munn Robert C. Nichol Nikhil Padmanabhan Aniruddha R. Thakar David H. Weinberg Donald York 《Monthly notices of the Royal Astronomical Society》2003,341(1):33-53
3.
The host galaxies of active galactic nuclei 总被引:2,自引:0,他引:2
Guinevere Kauffmann Timothy M. Heckman Christy Tremonti Jarle Brinchmann Stéphane Charlot Simon D. M. White Susan E. Ridgway Jon Brinkmann Masataka Fukugita Patrick B. Hall eljko Ivezi Gordon T. Richards Donald P. Schneider 《Monthly notices of the Royal Astronomical Society》2003,346(4):1055-1077
We examine the properties of the host galaxies of 22 623 narrow-line active galactic nuclei (AGN) with 0.02 < z < 0.3 selected from a complete sample of 122 808 galaxies from the Sloan Digital Sky Survey. We focus on the luminosity of the [O iii ]λ5007 emission line as a tracer of the strength of activity in the nucleus. We study how AGN host properties compare with those of normal galaxies and how they depend on L [O iii ]. We find that AGN of all luminosities reside almost exclusively in massive galaxies and have distributions of sizes, stellar surface mass densities and concentrations that are similar to those of ordinary early-type galaxies in our sample. The host galaxies of low-luminosity AGN have stellar populations similar to normal early types. The hosts of high-luminosity AGN have much younger mean stellar ages. The young stars are not preferentially located near the nucleus of the galaxy, but are spread out over scales of at least several kiloparsecs. A significant fraction of high-luminosity AGN have strong Hδ absorption-line equivalent widths, indicating that they experienced a burst of star formation in the recent past. We have also examined the stellar populations of the host galaxies of a sample of broad-line AGN. We conclude that there is no significant difference in stellar content between type 2 Seyfert hosts and quasars (QSOs) with the same [O iii ] luminosity and redshift. This establishes that a young stellar population is a general property of AGN with high [O iii ] luminosities. 相似文献
4.
Using ALSM to map sinkholes in the urbanized covered karst of Pinellas County,Florida—1, methodological considerations 总被引:1,自引:0,他引:1
Larry D. Seale Lee J. Florea H. L. Vacher Robert Brinkmann 《Environmental Geology》2008,54(5):995-1005
Comparison of a database of interpreted sinkholes made using airborne laser swath mapping (ALSM) with databases of sinkholes
made from interpretation of aerial photographs reveals substantial disagreement. The discrepancies involve the location, number,
areas, and circularity of interpreted sinkholes. Methodological factors that contribute to the discrepancies include blockage
of ALSM laser returns in thick vegetation, multi-path reflections, and misrepresentation of the true extent of sinkholes.
Comparison of two ALSM-derived databases made (1) independently from versus (2) in combination with earlier air photo analysis
in undeveloped regions had the following result: one-fourth of the sinkholes interpreted by using the composite method were
missed by the independent analysis, and one-third of the sinkholes that were interpreted from the independent analysis were
not interpreted as sinkholes using the composite method. Subjective interpretation leads to a high level of uncertainty such
that the results of the remote sensing studies are suspect, if not invalid. 相似文献
5.
M. Krämer Ri. Müller H. Bovensmann J. Burrows J. Brinkmann E. P. Röth J.-U. Grooß Ro. Müller Th. Woyke R. Ruhnke G. Günther J. Hendricks E. Lippert K. S. Carslaw Th. Peter A. Zieger Ch. Brühl B. Steil R. Lehmann D. S. McKenna 《Journal of Atmospheric Chemistry》2003,45(1):51-77
Several stratospheric chemistry modules from box, 2-D or 3-D models, have been intercompared. The intercomparison was focused on the ozone loss and associated reactive species under the conditions found in the cold, wintertime Arctic and Antarctic vortices. Comparisons of both gas phase and heterogeneous chemistry modules show excellent agreement between the models under constrained conditions for photolysis and the microphysics of polar stratospheric clouds. While the mean integral ozone loss ranges from 4–80% for different 30–50 days long air parcel trajectories, the mean scatter of model results around these values is only about ±1.5%. In a case study, where the models employed their standard photolysis and microphysical schemes, the variation around the mean percentage ozone loss increases to about ±7%. This increased scatter of model results is mainly due to the different treatment of the PSC microphysics and heterogeneous chemistry in the models, whereby the most unrealistic assumptions about PSC processes consequently lead to the least representative ozone chemistry. Furthermore, for this case study the model results for the ozone mixing ratios at different altitudes were compared with a measured ozone profile to investigate the extent to which models reproduce the stratospheric ozone losses. It was found that mainly in the height range of strong ozone depletion all models underestimate the ozone loss by about a factor of two. This finding corroborates earlier studies and implies a general deficiency in our understanding of the stratospheric ozone loss chemistry rather than a specific problem related to a particular model simulation. 相似文献
6.
W. L. F. Brinkmann Dr. R. Knickel Dipl.-Biol. J. W. Fachbereich Geowissenschaften 《GeoJournal》1987,14(3):361-366
Lake Seeloch is a wind-protected, small and shallow forest lake near Hanau, Rhine-Main area, that has neither surface inflow nor outflow. Wet and dry deposition of atmospheric pollutants and groundwater, but primarily the biochemical degradation of organic matter in the lake generates the bulk of dissolved constituents. Forest derived organic materials (pollen; debris; autumn-shed leaves) are the main sources of supply. Except for nitrate-nitrogen, all essential plant nutrients are available in very high, almost excessively high concentrations. Temporal and spatial distribution patterns of elements are established as a continuous recharge/release system at the water/sediment interface and in the lake water column, where processes related to organic matter decay play a dominant role. 相似文献
7.
W. L. F. Brinkmann Dr. H. Hahn H. Schick J. W. Fachbereich Geowissenschaften 《GeoJournal》1987,14(3):331-338
Two lakes, Lake Gänseweiher (LGW) and Lake Fechenheimer Weiher (LFW) occupy groundwater filled abandoned gravel pits which serve as fishing grounds and are part of recreational areas, respectively.Both lakes are cut into a near-surface groundwater aquifer, which is located in the pleistocene River Main gravel terrace t6. They are sealed at the base by miocene clays and above by overlying flood deposits of the River Main. The latter provide protection from pollutants derived from wet and dry deposition of atmospheric contaminants.Groundwater chemistry determines the pool of dissolved constituents in lake water. The temporal and spatial distribution patterns of chemical compounds in lake water are brought about by endo-biogenic processes, of which the indicators are nitrate-nitrogen and dissolved silica. The latter illustrates an instantaneous response to pulses of diatom blooms.Both lakes are eutrophic (polytrophic) according to the classification guidelines presented in literature. 相似文献
8.
9.
10.
Prof. Dr. R. Brinkmann 《International Journal of Earth Sciences》1971,60(3):886-899
Zusammenfassung In Anatolien gibt es drei grö\ere Kristallin-Massive — Menderes, Kirehir und Bitlis — neben zahlreichen kleineren. Das Kirehir-Massiv ist ganz aus vordevonischem Altkristallin aufgebaut. Menderes- und Bitlis-Massiv enthalten altkristalline Kerne. Eine intra-mesozoische Metamorphose umgab sie mit Hüllen von palÄozoisch-altmesozoischen Phylliten und Marmoren. Die metamorphe Aureole des Menderes-Massivs lÄ\t sich in die ÄgÄis, die des Bitlis-Massivs nach ZentralIran hinein verfolgen. Die Kristallin-Aufbrüche Nord-Anatoliens sind Bruchstücke einer alten Masse, der Nordanatolischen Schwelle; sie besteht aus Altkristallin. Die Taurus-Geosynkline hat ihre SelbstÄndigkeit durch die Schwellenzone gewonnen, die durch die intramesozoische Metamorphose in ihrem Rücklande geschaffen worden ist.
Für förderliche Erörterungen habe ich den Kollegen E.Baarir, Izmir,St. Dürr, Marburg, H.Haude, Hannover, E.Izdar, Izmir, F.Karl, Kiel, K.-O.Kopp, München, W.Niehoff, Hannover, J.Papastamatiou, Athen, J.Stöcklin, Teheran, für Fossil-Bestimmungen dem Kollegen E.Flügel, Darmstadt, zu danken. Der Deutschen Forschungs-Gemeinschaft und dem Aratirma Ileri Kurulu (Nr. 966/11) bin ich für Förderung der Feldarbeiten verpflichtet. 相似文献
In Anatolia there are three large crystalline massifs — Menderes, Kirehir and Bitlis — apart from a number of minor ones. The Kirehir Massif consists entirely of pre-Devonian metamorphites. The Menderes and Bitlis massifs both contain cores of old crystalline rocks. In the course of an intra-Mesozoic metamorphism these cores have been surrounded by envelopes of phyllites and marbles derived from beds of Paleozoic and Older Mesozoic age. The aureoles of young metamorphism can be traced from the Menderes Massif into the Aegean Sea and from the Bitlis Massif into Central Iran. The crystalline domes of northern Anatolia are fragments of the North Anatolian Welt, an ancient block composed of crystalline schists of probably pre-Paleozoic age. The Taurus geosyncline came into virtual existence by the ridge built up in its hinterland by the intra-Mesozoic metamorphism.
Résumé En Anatolie il y a trois vastes massifs cristallins — Mendérès, Kiréhir et Bitlis — sans parler de nombreux autres moins étendus. Le massif de Kiréhir se compose entièrement de roches cristallines pré-dévoniennes. Les massifs du Mendérès et de Bitlis contiennent des noyaux de cristallin ancien. Au cours d'un métamorphisme intra-mésozoique ces noyaux furent entourés des enveloppes de phyllite et de marbre dérivées des couches du Paléozoique et du Mésozoique inférieur. L'auréole métamorphique du massif du Mendérès se poursuit dans la Mer Egée, celle du massif de Bitlis jusqu'à l'Iran central. Les nombreux bombements cristallins de l'Anatolie du Nord représentent des fragments du Seuil Nord-Anatolien, ancien massif constitué par des schistes métamorphiques probablement précambriens. Le géosynclinal du Taurus a gagné son individualité par le ride cristallin s'étendant dans son arrière-pays et formé par le métamorphisme intramésozoique.
: Menderes, Kirsehir Bitlis — . Kirsehir — -. Menderes Bitlis , , . Menderes , Bitlis — . - , . . , , . .
Für förderliche Erörterungen habe ich den Kollegen E.Baarir, Izmir,St. Dürr, Marburg, H.Haude, Hannover, E.Izdar, Izmir, F.Karl, Kiel, K.-O.Kopp, München, W.Niehoff, Hannover, J.Papastamatiou, Athen, J.Stöcklin, Teheran, für Fossil-Bestimmungen dem Kollegen E.Flügel, Darmstadt, zu danken. Der Deutschen Forschungs-Gemeinschaft und dem Aratirma Ileri Kurulu (Nr. 966/11) bin ich für Förderung der Feldarbeiten verpflichtet. 相似文献